- Moisture Loving Fruit Trees – Fruit Trees That Grow In Wet Conditions
- Can You Grow Fruit Trees in Wet Soil?
- Damp Soil and Fruit Trees
- Use Cover Crops to Reclaim Wet Ground
- Do You Have Wet Soil?
- 6 Water-Loving Plants
- Consider Improving Your Drainage
- 9 Trees that Can Survive Flooding
- Managing Your Tropical Fruit Grove Under Changing Water Table Levels.
- Recovery from Flooding Stress
- Disease Control
- Geographic Location – Site Selection
- Soil Types
- Tropical Fruit Crops Flood and Drought Tolerance
- Land Preparation Practicies
- Six steps to good orchard site preparation
- How To Grow Fruit Trees
- Planting Fruit Trees
- Fruit Tree Planting Tips
- Pruning Fruit Trees
- Healthy Fruit Trees
- Growing Citrus Trees
Moisture Loving Fruit Trees – Fruit Trees That Grow In Wet Conditions
Most fruit trees will struggle or even die in soils that stay too wet for long periods of time. When soil has too much water in it, the open spaces that usually hold air or oxygen are obsolete. Because of this waterlogged soil, fruit tree roots are not able to take up the oxygen they need to survive and fruit trees can literally suffocate. Some fruit trees are also more susceptible to crown or root rots than others. These plants may take on significant damage from just short periods of wet feet. Continue reading to learn more about fruit trees that grow in wet conditions.
Can You Grow Fruit Trees in Wet Soil?
If you’ve found your way to this article, you probably have an area of the yard which retains too much
water. You may have even been given the advice that you should just plant a tree in that wet area so the roots can soak up all the excess moisture. While certain trees are excellent for wet soil and rainscaping, damp soil and fruit trees can be a bad mix.
Stone fruit, such as cherry, plum, and peaches, are highly sensitive to wet conditions and can develop many problems with rot or fungal diseases. Trees which have shallow roots, such as dwarf fruit trees, can also greatly suffer in damp soils.
When sites are flooded with excessively damp soils, you have about two options for growing fruit trees in the area.
- The first option is to berm up the area before planting fruit trees. This will allow you to plant any fruit tree in that site, while giving the fruit tree roots proper drainage. It is wise to berm the area up at least a foot high (30 cm.) to accommodate fruit tree roots.
- The other option is to select fruit trees that grow in wet conditions. While there is not an abundance of fruit trees that will grow in wet soils, there are some.
Damp Soil and Fruit Trees
Below are some moisture loving fruit trees, as well as fruit trees which can tolerate limited periods of excessive water.
Fruit Trees for Wet Soil
- Asian pears
- Anna apples
- Beverly Hills apple
- Fuji apple
- Gala apple
- Grafted citrus trees
- Surinam cherry
- Camu Camu
Trees That Tolerate Short Periods of Wet Soil
By: bowhunter18 Date:01-Oct-13
Does anyone have any advice on what apple trees to plant in my food plot when the soil is often wet? In spring there is about a half inch of standing water, but it dries out completely by mid august. So its generally pretty wet. Thanks, any advice is appreciated!!
By: Fuzzy Date:01-Oct-13
By: Fuzzy Date:01-Oct-13
What I am getting from my research (borne out by personal observation) is that apples (Malus) are more tolerant of “wet feet” than cherries/peach/plums (prunus) but that they aren’t going to thrive in swampy areas.
What you are describing is what soil scientists describe as a seasonal high water table (sometimes called a “perched water table”) that subsides through the primary growth months. This is less injurious to growth than a year round hydric condition ie: a “swamp”
Consider this: apple trees as a crop or food source exisist at a discrete landscape “point” while grasses and forbs are a “carpet” over the whole area… amending the soil and water table situation in a large area is difficult and costly (drain tile, site-grading, hauling in sandy or loamy material) but altering one or more “points” in the area is feasible even if only hand-labor is available.
If you have access to the site with a truck, “gator” or farm tractor with a bucket or trailer, you might bring in sand, gravel, compost and topsoil and build a raised mound or bed to plant in.
That way you can create an atificially deeper water table in the area where your tree(s) is/are. If your native soil is sandy/loamy (and many wettish areas do have well-drained soil types at the surface, with a restrictive layer of clay, rock, hardpan, or some other discontinuity underneath, “perching” the water table) you might just “borrow” native soil from the area around, to build the mound.
You can either build this mound to the diameter your tree roots will reach will reach when mature, or add diameter as the tree grows. Full-size (non-dwarf) apple trees will spread to about a 15 to 18 foot diameter crown when mature. The roots will reach about the same distance.
I am reading that most folks find a 24″ (two foot) separation to seasonal high water table is OK for apples, so you’ll want to find out where your seasonal high water table really is, and make up the difference with your mound of well-drained fill.
If you observe standing water at the surface for extended periods in the wet months, your seasonal water table is “zero” so you need to build up two feet.
If you only see standing water right after hard rains or swift snow melt, then this is a little tougher.
If you don’t have a soil investigation auger or Giddings probe (and who does except soil scientists?! LOL) Try digging a post hole, … look carefully at the soil as it comes out, and carefully note changes in texture : when wetted, it forms or does not form a firm ball… when wetted it is sticky or not sticky… when wetted it can or can not be pressed into a ribbon between thumb and finger that will not break under it’s own weight until over an inch and a half in length… note changes in density/compaction (digs hard, digs soft)… and color ie: uniform brownish, reddish, yellowish color that changes to gray-speckled, pale tan, , pale yellow speckled/mottled with, solid gray, blue-gray, or gray-brown, and/or splotches of red, orange, and maybe coatings of black material looking like charcoal (Manganese Dioxide) that fizz when you pour hydrogen peroxide (the medicine cabinet kind) on them.
All these changes are (usually) seasonal water table indicators. When/if you find them (or standing water, of course) then that’s your seasonal water table. Build your mound “plus that depth” to make up 24″ total and wide enough to accomodate the width your tree roots will reach.
This sounds like a lot of work, but an apple tree is a lifetime investment.
By: glacier Date:01-Oct-13
Good advice above… I would recommend building your mound as big as you want it to begin with, since you can suffocate roots by adding dirt later.
Apples will tolerate ‘wet feet’ for short periods (a week or two, MAYBE three) but the roots will suffocate if left in fully saturated soil for longer than that.
The mounds above are one solution, and keep in mind that the dirt in the mound will settle, so building mounds this year and planting a year or two later may help avoid future problems. How much it settles is very dependent on your soil type. At my house, I filled the 7 foot trench for my water line and really didn’t do any compacting, and two years later I had about 2 inches of settling. I filled that back to level and it has been fine now for 5 years. On the other end of the spectrum, my father in law filled a 7 foot trench for a water line, and ran a jumping jack compactor on it in 2 foot lifts, and the next spring he had about 18 inches of settling. He has been filling that trench every spring for three years, and this spring it was only about 5 inches low.
Depending on what the lay of the land is, you might be able to just dig some drainage ditches or trenches and lower that seasonal water table a foot or two. If it were me, I would probably use the native soil and dig pits and trenches to build my mounds. if the water table stays high, you could then have some areas that hold standing water, which may be a good thing if you are in a mostly arid area or it could just be a great place to raise mosquitoes…
Also, depending on your local laws, look into what you have to do if this is considered a ‘wetland’ before you start moving dirt…
By: r-man Date:01-Oct-13
its like this, if the area to plant may have standing water for long periods , say 6-7 days, you will need to crown up the area, that means besure that the crown is twelve inches above even short standing water, best to raise 6-8′ circle or provide ditch for water run off. root tip can tolerate very moist siol for months
By: Fuzzy Date:01-Oct-13
I love these threads. I learn so much.
By: Fuzzy Date:01-Oct-13
good discussion here
By: Fuzzy Date:01-Oct-13
another good one…
Use Cover Crops to Reclaim Wet Ground
Because the beneficial bacteria and fungi play important roles in the cycling of nutrients within the soil, their loss can create nutrient-deficient growing conditions for subsequent crops.
Purple corn syndrome, for instance, is a crop condition resulting from soil becoming deficient in beneficial organisms.
“Corn is very reliant on the activity of mycorrhizal fungi in the soil in order for its roots to access phosphorus,” says Fisher. “When the beneficial fungi can’t colonize, the corn turns purple. This indicates a phosphorus deficiency in the crop.”
Soil structure suffers as well when wet ground remains unplanted. “Without living roots in the soil, the stability of soil aggregates starts to break down,” says Fisher.
As a result, pore space shrinks, restricting oxygen. This contributes to a further sealing of the soil, delaying the drying of wet ground.
“These conditions lead to a continuing breakdown of total soil function,” Fisher says. “It’s hard to rebound from that. The first thought is to break up the soil with tillage after the field dries out. This only further diminishes soil structure and destroys soil organic matter. It simply compounds the problem.”
An alternative for reclaiming wet ground is the planting of a diverse cover crop as soon as conditions permit. The greater the diversity of the cover, the broader the range of soil services fostered by the diverse colonization of the resulting soil life.
If the cover crop is planted in early to midsummer, warm-season species like cowpeas, soybeans, and sunflowers are good options. Warm-season grass species are also beneficial. Sorghum, sorghum sudan, and millet are particularly effective at promoting mycorrhizal activity.
“Including a clover in the mix is helpful,” says Fisher. “Red or alsike or sweet clover can tolerate a broad range of conditions. Each adapts to both dry and wet soil conditions; sweet clover tolerates salinity. A deep-rooted legume can break through compaction.”
Late-season plantings of a cover crop in wet ground might include cool-season species such as barley, cereal rye, winter peas, crimson clover, and brassica crops like oilseed radishes, rapeseed, and turnips.
“Oats makes a good choice for cool-season planting,” says Fisher. “Oats is a quick starter. It’s a good option for recolonizing populations of good bacteria and the mycorrhizal community as quickly as possible.”
Cover crops lend themselves to aerial seeding. Maximum benefits from cover crops result from letting the plants grow full season. This lets the beneficial community of fungi and bacteria continue growing into winter, maximizing their populations.
In the short term, cover crops reclaim wet ground by the moisture they consume, using as much as 7 inches of soil water in one season.
Longer-term reclamation comes from improved soil health. “The rebuilt soil aggregates and plant roots create channels for moisture to flow through the soil,” says Fisher. “This lets surface soil dry out while adding to the bank account of soil moisture stored at deeper levels.”
When you consider gardening in a heavily watered area, it is important to know which plants will thrive.
Anything, from the sun you get to the seeds you buy, can affect the growth of your plants. When people struggle to grow healthy plants, it’s often because they live in wet climates—either it rains a lot or they’re near a body of water.
Not to worry—some plants love the water just as much as you.
Do You Have Wet Soil?
You may think that you have fairly wet soil, but your drainage could be so good that it doesn’t necessarily affect your plants. It is important to distinguish whether water is from the soil or due to drainage issues. Here is an easy way to determine what type of soil you have.
Start by digging a small ditch with a straight side and approximately 2 ft. deep. Covering the ditch to keep rain from interfering, leave the ditch overnight.
In the morning, if water has collected, you have a high water table. A high water table often occurs when you’re close to sea level. In conclusion, this indicates you have wet soil.
To test your drainage, fill the already dug ditch approximately half way and cover it for 24 hours. If water remains when you uncover the ditch, you may have to work on your yard’s drainage.
6 Water-Loving Plants
1) Swamp Azaleas
Swamp Azaleas (Rhododendron viscosum) produce a hearty, white flower for your green backyard. This shrub is perfect for the front of your house, or the edge of your yard, because it grows to be around 5 ft. tall and 12 ft. wide.
Rusty Clark / Flickr (Creative Commons)
This perennial is so hearty that it is actually described by Lady Bird Johnson Wildflower Center as ““flood tolerant.” If your yard often floods after rain, or holds water, these rhododendrons are perfect. In addition, the Swamp Azaleas are beneficial for bumble bees.
If you’re looking to liven up your yard, another possibility is planting Primrose. These plants flower in multiple colors, with variations from red, orange, pink, yellow, and white. These plants begin to blossom in early spring and continue blossoming through the summer.
stanze / Flickr (Creative Commons)
Primrose does well in wet soil because it is a hardy plant that can adapt to many different climates. Though it is important to have proper drainage for these plants to grow healthily.
3) Bee Balm
For more color, and something that attracts hummingbirds and butterflies, try planting Bee Balm. This perennial can grow quite large and produces vibrant pink flowers that will liven up your space. Along with attracting butterflies, Bee Balm resists deer.
terren in Virginia / Flickr (Creative Commons)
Bee Balm, otherwise known as “Pardon My Pink,” thrives in damp climates because it does best in moist soil.
4) Elephant Ears
There is nothing more tropical than planting a few Colocasias, commonly called Elephant Ears, in front of your house. Be sure to leave plenty of room for these guys because they can grow to be quite large. In fact, the foliage resembles an elephant’s ear, hence the name.
Clyde Robinson / Flickr (Creative Commons)
These hearty plants do very well in wet soil; however, they prefer warmer climates. During the cooler months it is recommended to cover these plants, or bring them indoors.
Growing to about three feet tall, Jack-in-the-Pulpit loves a moist climate and needs very little care overall. This interesting plant produces a hooded flower that grows out of its own individual stalk.
Jack-in-the-Pulpit is a unique plant that looks like no other, and it will thrive in forest areas, woodlands, swamps, and marshes.
6) The Bleeding Heart
The Bleeding Heart, or the Dicentra spectabilis, is fast growing and needs consistent watering to grow.
The Bleeding Heart produces flowers that vary in shades of red and are shaped like small hearts.
Rona Proudfoot / Flickr
They bloom in late spring and easily germinate by themselves if left alone. In addition, the Bleeding Heart attracts hummingbirds and is deer resistant.
Consider Improving Your Drainage
The several plants mentioned above will do well in wet climates and liven up your living space. Even with these plants, the drainage in your yard should not be neglected. Standing pools of water can easily attract mosquitoes with dangerous diseases.
In some cases, standing water from poor drainage can even cause root rot in the hardiest of plants.
Signs of root rot are yellowing or drooping leaves that will eventually die if not treated. Root rot can spread to other healthy plants, and may even stay in the soil after an infected plant dies.
Wilting caused by root rot. Scot Nelson / Flickr (Creative Commons)
There are two causes of root rot. Although a fungus can lead to root rot, over-watering is the most common cause. This is the main concern for planters trying to grow in wet climates. Therefore, it is important to consider improving your drainage before planting.
Enjoy these six plants that will thrive even in wet climates.
Freelance writer Marlene Ridgway grew up in rural West Virginia, cooking, keeping chickens, stacking firewood, picking blueberries, and gardening.
After a wet spring and a number of heavy rains there are fields with drowned crop or in some cases fields that have not been planted. Rather than let the weeds grow this offers an opportunity for soil improvement with cover crops. Wet holes or depressional areas usually will benefit from some soil improvement – typically there has been some movement of fine textured soil particles that tends to seal the area and prevent water movement. While cover crops will add more surface crop residues, well established growing cover crops will help to dry wet areas or fields. Crop residues will also start to break down faster under the canopy of a growing cover crop. In turn cover crop roots will help to stabilize the soil and improve infiltration to aid in water drainage.
There are a number of things to consider when selecting a cover crop to cover and improve these wet fields:
- Do you have any nitrogen or herbicide on?
- What is the crop plan for fall 2015 – spring 2016?
- How are you going to plant the cover crop?
Planting the Cover Crop
Let’s start with the last one – how are you going to plant the crop. Is the field or area dry enough to get across yet? How much crop residue is present? There are fields with heavy drifts of residue that have floated in and concentrated in areas. Some of the unplanted acreage includes heavy clay soils with corn residue from last year – how is the best way to establish a cover crop there? Drilling in the cover crop would work best in the high residue situation but those soils are slow to dry this year. Another option is to broadcast the cover crop seed and hope there is enough moisture to get started. In that case choose cover crops that germinate fast and grow fairly aggressively so that they can get a root down into that blanket of residue. Cereal crops like oats, barley and rye generally will achieve a cover crop stand if broadcast and the weather is favourable.
Where Nitrogen was Applied
Do you have any nitrogen applied to the field? Even after all the rain there is still probably a good amount available for a cover crop. Generally the grasses and non legume broadleaf cover crops like radish are very good at scavenging nitrogen. Legumes will also pick up nitrogen, they are just not quite as efficient. One caution – radish and other brassicas like turnip do not do well on wet soils so may not be an appropriate choice for wet areas unless used in a mix.
Cover Crop Options – no herbicides applied
Options for fields with no herbicides applied
|When will the cover crop seed be applied?||2016 – corn||2016 – soybeans||Fall 2015 – wheat|
|July||sorghum sudan, millet, cereal rye, oats or barley,mixes especially with legumes like clover, peas or vetch||sorghum sudan, millet, cereal rye, oats or barley,multi mixes (avoid vetch or significant amounts of legume in the mix)||Buckwheat would achieve the most growth BUT needs to be controlled promptly to avoid seed set.Avoid cereal grasses|
|August||cereal rye, oats, barley,mixes especially with legumes like clover, peas or vetch||cereal rye, oats, barley,multi mixes (avoid vetch or significant amounts of legume in the mix)||Not a large enough window for growthAvoid cereal grasses|
Note – many legumes like clover are slow to establish and may let weeds get well established, use only in mixes.
Options for Fields with Herbicides Applied
Rain and wet soil conditions may have had an influence on the applied herbicides. Some may have leached lower in the soil profile while others may have degraded more due to microbial activity. Increased soil moisture does not always increase microbial activity; if the soil has been under anaerobic conditions ie waterlogged, herbicide like Treflan and Prowl will take longer to break down. Refer to the herbicide tables below developed by Dr. Darren Robinson of the University of Guelph, Ridgetown Campus.
Herbicide Persistence and Rotation to Cover Crops after Corn and Soybeans
Two important factors influence the potential for carryover injury to rotational crops: 1) how long the herbicide persists in the soil, and 2) the sensitivity of the cover crop to herbicide residues. Herbicides with shorter half-lives (the time it takes for 50% of the active ingredient to dissipate) are always less of a concern. Of course several factors influence the rate of dissipation such as rainfall, soil texture and soil pH, etc., however, most guidelines generally are for “normal” conditions (e.g. not severe drought). In general, products with a 4 month or less rotation restriction for the species of interest, close relative, or sensitive species (i.e. clovers) should pose little problem. These products typically have half-lives of less than 30 days. Species sensitivity can play a role if only a small amount of residue is necessary to cause injury and the herbicide persists. Quite often, small seeded legumes and grasses like the clovers and ryegrass and mustard species like tillage radish are very sensitive to some herbicides.
The following table provides some persistence and carryover information for some commonly used corn herbicides. Some of this information is our best estimate.
Table 1. Common corn herbicides, estimated half-lives, and their potential to injure fall-seeded cover crops.
Flood and Drought Tolerance of Tropical Fruit Trees
From the Horticultural Sciences Department, Florida Cooperative Extension Service
Institute of Food and Agricultural Sciences, University of Florida
Flood Tolerance Definitions
Tolerant – Flood tolerant fruit crops will survive excessively wet (high water table) and flooded conditions for several days to a few weeks.
However, the stress of wet conditions may reduce tree growth and fruit production. In addition, root diseases may develop and result in tree damage or death.
Moderately tolerant – Moderately flood tolerant trees will survive several days of excessively wet or flooded soil conditions. However, the stress of wet conditions may reduce tree growth and fruit production. In addition, root disease may develop and result in tree damage or death.
Not tolerant – Trees not tolerant of wet or flooded soil conditions. Trees may sustain heavy damage or be killed by one to a few days of wet soil conditions.
Flood tolerance of tropical and subtropical fruit crops based on the literature and field observations
|Tolerant||Moderately tolerant||Not tolerant|
|Caimito||‘Tahiti’ lime||Mamey sapote|
Drought Tolerance Definitions
Tolerant – Trees tolerate lack of water for a few days to several weeks. However, drought stress may reduce tree growth and yields.
Moderately Tolerant – Trees may withstand several days of drought. However, drought stress may reduce tree growth and yields.
Not Tolerant – Trees may survive a few days of drought. However, this may result in severe leaf drop, poor vegetative growth, and a large reduction in yield.
Drought tolerance of tropical and subtropical fruit crops based on the literature and field observations
|Tolerant||Moderately tolerant||Not tolerant|
|Grafted citrus||Avocado||Air-layered citrus|
Managing Your Tropical Fruit Grove under Changing Water Table Levels, University of Florida pdf
Planting and Growing Page
9 Trees that Can Survive Flooding
It’s that time of year, where storms, hurricanes, and flooding become more common. Storms deliver torrential rain that can lead to massive flooding, damaging homes, businesses, and sometimes our community trees. But some tree species are more tolerant than others at withstanding the impact of a storm and its aftereffects like puddles, soil deposition, and rushing streams.
Here are 9 tree species that can weather a storm in wet soil and flood conditions.
1. River Birch
As its name suggests, the river birch naturally grows along river banks. But as a landscape tree, it can be planted almost anywhere in the U.S. The species is valued for its relatively rapid growth, tolerance of wetness and some drought, unique curling bark, spreading limbs and relative resistance to birch borer.
The river birch has not yet reached the popularity of many maples and oaks, but it is well on its way. In 2002, one of its cultivars was even named the Urban Tree of the Year by the Society of Municipal Arborists.
Hardiness zones 4-9.
Read: How You can Help Restore Communities and Forests Devastated by Recent Hurricanes
2. Black Tupelo
Called “one of the best and most consistent native trees for fall color” by tree expert Michael Dirr, the black tupelo is a terrific landscaping choice. Displaying various hues of yellow, orange, bright red and purple—often on the same branch—its foliage is a stand-out of the autumn season. Even the distinctive bark, which resembles alligator hide, adds visual and textural interest.
And while its blooms may not seem noteworthy, bees will be very appreciative of the presence of this tree, as it serves as an important late-spring food source.
Hardiness zones 4-9.
3. Weeping Willow
This graceful giant is known for its open crown of wispy, ground-sweeping branches and long, slender leaves. Often seen as one of the first indications of spring, the weeping willow’s yellow twigs and green foliage appear early in the season—sometimes as early as February.
The tree is easy to grow and quick to take root, reaching heights between 30′ and 40′ and nearly the same in width. It lends itself well to planting singly or in small groves near the edge of ponds, lakes and rivers.
Hardiness zones 6-8.
The Baldcypress tree is the classic tree of southern swamps. There, in its habitat, it displays a peculiar habit of raising conical “knees” from its roots. The function of these growths is something of a mystery, although some believe it is a way to help the roots get oxygen. This tree dwells in swamps because it out-competes most other trees on such sites.
To the surprise of some people, the baldcypress does quite well when planted in the right soil in yards or along streets and is a beautiful specimen tree. It has been grown successfully in cities as far north as Milwaukee and on dry Texas hills.
Hardiness zones 4-10.
5. Red Maple
Red maple is one of the best named of all trees, featuring something red in each of the seasons—buds in winter, flowers in spring, leafstalks in summer, and brilliant foliage in autumn. This pageant of color, along with the red maple’s relatively fast growth and tolerance to a wide range of soils, makes it a widely planted favorite.
The natural range of red maple begins roughly at the eastern edge of the Great Plains north to Lake Superior, extending eastward to the Atlantic. But homeowners and urban foresters are growing this tree all across the United States.
Hardiness zones 3-9.
Read: Are You Ready for Hurricane Season?
The hackberry, while often forgotten by casual consumers, is commonly heralded by tree experts as “one tough tree.” Found on a wide range of soils east of the Rockies from southern Canada to Florida, these trees thrive in a broad span of temperatures and on sites that vary from 14 to 60″ of annual rainfall. They can even stand up to strong winds and tolerate air pollution.
All this hardiness adds up to a good landscape choice, particularly if you’re looking for an energy-conserving shade tree that doesn’t require watering.
Hardiness zones 3-9.
7. American Sweetgum
The American sweetgum—with its star-shaped leaves, neatly compact crown, interesting fruit and twigs with unique corky growths called wings—is an attractive shade tree. It has become a prized specimen in parks, campuses and large yards across the country.
If you’ve got the space and are looking to add some fall color, this tree is a sure bet. The glossy green leaves turn beautiful shades of yellow, orange, red and purple in the autumn.
8. Overcup Oak
The overcup oak tree is a long-lived, very sturdy shade tree that will thrive in a wide variety of soil conditions. Long overlooked by growers, the tree is gaining popularity and has been made more readily available for home landscapes.
Because of its size, shape, adaptability and hardiness, the overcup oak makes an excellent urban street tree.
Hardiness zones 5-9.
9. California Sycamore
The California Sycamore is a majestic native with a rapid growth rate. In expansive landscapes, it can make a fine specimen tree. Standout features include a peeling, mottled trunk; a spreading crown; heat and wind tolerance; and enormous size.
While it is a beautiful tree, several factors should be considered when planting it, including size, fruit, dense branching, roots and moisture requirements.
Hardiness zones 7-10.
Managing Your Tropical Fruit Grove
Under Changing Water Table Levels.
C.F. Balerdi, J.H. Crane and B. Schaffer, University of Florida
This fact sheet has been prepared by IFAS staff working with tropical fruit crops in an effort to help growers manage their groves under conditions of flooding or high water tables. Although weather events cannot be controlled, becoming familiar with the effects of high water table on tropical fruit crops can help growers survive these events with minimal or no damage. However, this process will be impacted by water levels, which are managed in South Florida and thus are dependent on water management decisions.
Recovery from Flooding Stress
Tree symptoms of flooding stress
Symptoms progress from 1 to 3.
- leaf wilting and browning (scorching)
- fruit drop and leaf chlorosis and leaf abscission (drop)
- stem dieback, limb dieback, tree death
Documentation and reporting
- Report damage to the Farm Service Agency (FSA) (tel: 305-242-1197) as soon as possible after the event. Ask FSA is it is ok to begin repair and recovery of trees.
- Photograph flooding and damage to the trees.
Steps in recovery
- Allow the flood-water to subside.
- Remove a portion of the tree canopy. This will reduce the transpirational load on the root system.
- Removing fruit from the tree may decrease stress.
- If registered for your crop and symptoms appear apply fungicide according to label instructions.
Note: Damage may be more severe on young trees than on large mature trees. Trees with fruit tend to have a more severe negative reaction to flooding than trees without a fruit load.
- Wait several weeks to evaluate the extent of damage or tree death. This is because it takes time for trees to recover or for trees to decline from flooding. As an example, sometimes trees may lose leaves or have scorched leaves but the tree recovers.
Under flooding/high water table conditions root diseases proliferate. This is specially true of the disease causing “water molds” – Pythium and Phytophthora. For groves that are located in low, flood prone areas or areas of high water table, the grower has to be aware that, these fungi can attack tree roots and cause severe losses. These diseases spread very fast and growers cannot afford to wait for a long time before taking remedial actions. Two fungicides are commonly used to stop the spread and the damage of these diseases – Ridomil and Aliette. Ridomil is usually drenched around the root area and Aliette is sprayed on the foliage or injected into the trunk. However, these fungicides are only registered for citrus and avocados. Timely use of these compounds on labeled crops can be very effective in avoiding extensive damage. On the other hand, repeated, preventative treatments should be avoided as resistance to these products can develop, as it is already happening with Ridomil on citrus in some areas of Florida.
In previously planted groves that were recently flooded or suspected to be subject to flooding in the future we recommend replanting those trees that have died on 3 ft high mounds or higher. If you lose entire rows you should consider making a 3 ft high beds. You may also want to consider replanting with flood tolerant tropical fruit crops (see Table 1).
Geographic Location – Site Selection
Before you purchase land find out what the elevation the property has. This information may be obtained from the land title, or the Natural Resources Conservation Service in Florida City has topography maps with land elevations. Elevations at or below 4-6 feet may be subject to periodic flooding in some areas. In addition, view adjacent property for what agricultural activity is occurring, e.g., container nursery, fruit crop, vegetable crop and potential signs of flood damage (e.g., dead plants). Speak with potential neighbors concerning past conditions of the land you intend to buy as to flooding. You may also want to contact the Dade County Cooperative Extension Service and speak with an agent about the property.
There are two basic soil types in most of the land in South Dade, the dark marls and the rock soils. Tropical fruit trees should only be planted in rock soils. There are very few cases where some tropical fruit groves have been planted in marl. The soil going into the planting hole must be the same soil that was removed from it. Do not add any other soil to the planting hole! Muck, marl, peat, etc. hold a lot of water and provide a good environment for root disease development. There are some poorly drained sandy soils in the north end of Dade County. Although there is no commercial agriculture in this area the same principles apply for dooryard plantings.
Tropical Fruit Crops Flood and Drought Tolerance
Tables 1 shows the relative sensitivity of tropical and subtropical fruit crops to flooding or high water table and drought, respectively. For south Miami-Dade, flooding tolerance may be more important than drought tolerance. This information was compiled from several sources. Flood tolerance is dependent upon crop species, prior plant stress (e.g., freezing weather, drought), crop load, air temperatures (warm\hot temperature more detrimental), soil type, flooding depth and flooding duration.
Definitions used for flood tolerance are:
- Tolerant – Flood tolerant fruit crops may survive excessively wet (high water table) and flooded conditions for several days to a few weeks. However, the stress of wet conditions may reduce tree growth and fruit production. In addition, root diseases may develop resulting in tree damage or death.
- Moderately Tolerant – Moderately flood tolerant trees may survive several days of excessively wet or flooded soil conditions. However, the stress of wet conditions may reduce tree growth and fruit production. In addition, root disease may develop resulting in tree damage or death.
- Not Tolerant – Trees not tolerant of wet or flooded soil conditions may sustain heavy damage or be killed by a day or few days of wet soil conditions.
Drought tolerance is dependent upon crop species, prior plant stress, and crop load. Drought reduces growth and yields of tolerant and non-tolerant crop species.
- Tolerant – Tolerates lack of water for a few days to several weeks. However, drought stress may reduce tree growth and yields.
- Moderately Tolerant – Trees may withstand several days of drought. However, drought stress may reduce tree growth and yields.
- Not Tolerant – Trees may survive a few days of drought however, this may result in severe leaf drop, poor vegetative growth, and a large reduction in yield.
Land Preparation Practicies
Owners of land in areas that are subject to flooding, excessively wet soil conditions, or that have a low elevation (4-7 ft) should seriously consider planting trees on beds or mounds. This will increase the chances that part of the root system is above flooded or wet soil conditions in the event of flooding. To create enough soil to bed trees, deep scarification with a “rock plow” or asphalt scrapper is needed. We recommend enough soil be “created” to make beds or mounds 3 ft high (there will be some settling with time). We have observed some bedded avocado and lime and mounded mamey sapote groves that have survived periodic flooding in the past. (Caution: This is not to say all trees survived or that they will survive future flooding events).
Irrigation is needed for the well-being of tropical fruit tree groves in both, high and low elevation land. Irrigation (or some way of watering) is essential in newly planted and young groves. Depending on the species planted, as groves mature, less water may be needed though many species will benefit from irrigation from fruit set to harvest. Excesses of water can create problems, besides being wasteful and expensive.
The choices of an irrigation system for tropical fruit trees in high or low elevation land are: microsprinklers and regular high volume over or under tree sprinklers. The formers are more efficient in water use, thus recommended in areas with scarcity of water. A good microsprinkler system could also be used for cold protection although this has not been tested. High volume systems use quite a bit more water but give better cold protection. Naturally, in the same area, the soil of bedded or mounded groves will dry faster than that of flat planted groves where the water table is closer to the roots so more frequent irrigation may be needed.
Tropical trees in flood prone/high water table areas may need special fertilizer considerations. Because in these areas water is so close to the surface, growers should consider increasing the frequency of fertilizer applications but reducing the amount applied each time provided that the total recommended amount is applied to each tropical fruit crop. Also consideration should be given to not applying fertilizers during rainy periods to avoid fertilizer leaching.
Table 1. Flood tolerance of some tropical fruit crops.
Sugar apple (anon)
Mango, Carambola, Banana
Atemoya, Passion fruit, Jackfruit
Air layered citrus
Lychee, Longan, Carambola, Caimito, Coconut, Guava, Jackfruit, Sugar Apple, Atemoya
Based on experiments with containerized plants, field observations and literature.
Six steps to good orchard site preparation
Hilling-up of the surface soil is done with a road grader. (Courtesy Bas van den Ende)
A research report by Judy Tisdall, soil scientist at La Trobe University, Melbourne, and Bas van den Ende, a tree fruit consultant in Australia’s Goulburn Valley.
Establishing a high-density orchard is costly. It’s important to do it the right way, because you only have one chance. Once the orchard is established, it is difficult and costly to correct soil problems in later years, yet properties in the soil affect the growth of roots.
To produce high yields of good-quality fruit, trees need lots of feeder roots in the surface soil so they can take up plenty of water and nutrients. To enable this, the surface soil should be deep, soft, stable, well-structured, well-drained, fertile, and cool in summer. The pH level should be between 5.8 and 6.5.
So, you need to improve the fertility and structure of the surface soil and increase the depth of surface soil if it is shallow in your orchard.
Here are six steps to preparing the soil:
1) Have your soils tested
Whether it is new land or old orchard land, have the surface soil tested to see if you need to add lime, gypsum, and/or phosphorus, and to what depths.
Methods for collecting, preparing and submitting soil samples vary in different regions, states and countries. These methods are described on various websites, so follow the methods appropriate for you.
As you sample the soil, you will also see how deep the surface soil is and whether there are any hard layers that restrict water, air, and roots from penetrating deeper layers.
Lime will be needed if the soil pH is acidic (5.7 or less). Gypsum will be needed if the soil is hard due to dispersion. Phosphorus will be needed unless superphosphate has previously been applied each year to the soil and a soil test shows that there is an adequate amount of soluble phosphorus available to the young trees.
2) Grade your block (if necessary)
Before applying the lime, gypsum and/or phosphorus (if soil test results indicate these are needed), laser-grade the block to make sure that it has a slight slope (e.g. 1 in 80) so that excess water will drain from the surface of the soil. This will help avoid waterlogging of the surface soil.
3) Apply amendments and rip and cultivate the soil
Some surface soils are naturally hard and dense, while others have a plow sole or shallow hard pan due to excessive cultivation and traffic. All these hard layers need to be broken up. After spreading lime, gypsum, and/or phosphorus (if soil tests indicated these were needed), rip the soil both ways to a depth of about 300 to 400mm. Be careful not to mix heavy subsoil with the surface soil.
After ripping the soil, slightly cultivate the moist, but well-drained, surface soil to form small clods. Do not pulverize the soil, which would happen if the soil was cultivated when too dry. This is also the time to put in the mains and sub-mains of a new irrigation system.
Lime and phosphorus are not very soluble and move very slowly in soil, so they need to be cultivated into the surface soil. Apply agricultural limestone (calcium carbonate) over the whole block, but apply superphosphate along the future planting lines about 1 to 2 meters (3 to 6 feet) wide and rototill it in. Phosphorus is important for root growth, and young trees will benefit from phosphorus if it is nearby, i.e. if mixed into the surface soil.
Gypsum is moderately soluble, so, if applied to the soil surface, it might eventually be washed down the profile to the subsoil.
Why do some soils need lime?
The feeder roots in the surface soil need soft, stable, well-drained soil, with a pH of between 5.8 and 6.5. In acidic soils (with a pH below 5.8) excess aluminum and possibly manganese become available and are directly toxic to roots. The roots become stunted and unable to take up sufficient water and nutrients.
Other nutrients such as calcium and magnesium may be present in acidic soil but become unavailable to roots. Also phosphorus and sulfur may be present in acidic soil, but combine with aluminium to form aluminium phosphate and aluminium sulphate compounds, which cannot be taken up by roots.
Why do some soils need gypsum?
Gypsum (calcium sulfate) is sometimes needed to soften surface soils and to improve their structure.
With gypsum, the soluble calcium swaps with some of the exchangeable cations, such as sodium and magnesium. Gypsum does this better than lime does, because gypsum is more soluble than lime. Gypsum does not affect soil pH, but lime does.
Cations (positive ions) such as sodium and calcium exist in soil as either exchangeable cations (loosely bound to clay particles) or soluble cations (dissolved in soil water). The soluble cations often swap with exchangeable cations in soil. When exchangeable sodium makes up more than 5 percent of the total exchangeable cations, and there are low concentrations of soluble cations, the soil is sodic and unstable.
Sodic surface soils are very dense and hard, so it is very difficult for feeder roots to grow through them.
When sodic soils are wetted, the clay particles push each other apart. First the aggregates swell and decrease the size of the pores. On further swelling, small groups of clay particles separate from the larger aggregates and become suspended in the water until the clay particles block the small pores. This is called soil dispersion.
4) Hill up the surface soil
Most feeder roots grow in the surface soil, so when the surface soil is shallow, these roots are severely restricted. Few roots grow in the compacted surface soil in the traffic lanes between rows of trees. If the land is also flat, the soil can easily be waterlogged in wet conditions.
To solve these problems, use a road grader to take the wasted surface soil from the traffic lanes, and hill-up the surface soil before you plant the trees. This increases the volume of surface soil for the feeder roots to explore, and the sloping beds also allow excess rain water to run off. Surface drainage is as important as irrigation in wet climates.
5) Sow ryegrass onto the beds or let voluntary weeds develop
This step must be carried out in early autumn to ensure that the ryegrass or weeds become established before the winter sets in. Use irrigation water to germinate and establish ryegrass or weeds.
6) Spray out ryegrass or weeds before you plant trees
Ryegrass or weeds are needed to keep the soil covered to avoid impact from heavy rain, avoid impermeable crusts from forming, and to stabilize the soil. Kill the ryegrass or weeds in spring, because they compete with trees for water and nutrients during the growing season. The dead roots of ryegrass or weeds have done their job in improving soil structure.
How To Grow Fruit Trees
Growing cordon fruit trees is the most simple and popular way of training fruit trees to create a traditional tree with a clear stem and a well formed crown. Dwarf fruit trees or patio fruit trees are ideal for smaller gardens, or you could try growing family fruit trees for a several varieties on one plant!
For a stunning garden feature, try growing espalier fruit trees against a fence or wall, or step-over fruit trees around the vegetable plot.
Growing fruit trees is easy; just follow our quick guide to get the best out of your tree.
Planting Fruit Trees
When you receive a bare root fruit tree it will arrive in a dormant state as this is the perfect time for transporting and planting it. Try to plant fruit trees as soon as possible; if this is not immediately possible, you will need to soak your bare root fruit trees in a half filled bucket of water to moisten the roots and stand it is a cool frost free place. The tree will remain in good condition for a week or so. If planting will be delayed for longer, the tree should be heeled in to a temporary planting hole in the soil.
Grow fruit trees in a sunny and sheltered position, and make sure the site has good quality and well-drained soil. Digging in plenty of well-rotted manure or compost will improve your soil. Make sure you allow enough room for your tree to grow in future years.
Dig a generous sized hole at least a third wider than the roots. Hammer in a stake before inserting the tree into the hole to avoid damaging the roots. Spreading the roots in the hole, making sure the tree is at the same level that it was planted in the nursery (the soil mark on the stem should be obvious). Secure the tree to the stake with a tree tie, making sure that the tree does not rub on the stake. Backfill the remaining soil around the roots and gently firm the soil in with the sole of your shoe.
Water your fruit tree thoroughly after planting and ensure that the tree is kept well watered during its first year until established. A nutrient supplement or balanced fertilizer will help promote healthy growth. Check tree ties regularly and loosen them if necessary to prevent rubbing on the stem. The stake can be removed after two years.
When growing fruit trees in pots, use a large container and soil-based potting compost such as John Innes No. 3. Containerised plants will need more frequent watering than those grown in the ground.
Fruit Tree Planting Tips
To ensure effective watering, insert a piece of plastic pipe with holes drilled in the sides, reaching from the base of the roots to just above the soil level. This should be put in place at the time of planting the tree to channel water to where it is needed, whilst minimising the problem of surface rooting.
To ensure effective watering, insert a piece of plastic pipe with holes drilled in the sides, reaching from the base of the roots to just above the soil level. This should be put in place at the time of planting the tree to channel water to where it is needed, whilst minimising the problem of surface rooting.
Pruning Fruit Trees
The aim of pruning a fruit tree is to create a well formed tree, with well spaced branches which are not overcrowded. This allows plenty of light to enter to ripen the fruit and also encourages good air circulation which reduces the spread of disease. It is important to get this right from the beginning, as it is very difficult to put mistakes right later on.
Apple and pear tree pruning should be carried out in the winter months, between November and February, when the tree is dormant and it is easier to see the shape of the tree. If youre growing cherry trees, plums, apricots or peaches these should be pruned in the summer to reduce the risk of silver leaf disease.
When growing cordon fruit trees, pruning begins immediately after planting. Remove the central stem to just above the highest side branch. For the following 3 years, prune only the tips of the remaining main branches by one third in winter. Aim for about six well spaced main branches which will form the frame of your tree, with fruiting sub branches growing off of them. Always cut back to an outward facing bud, to encourage growth away from the centre of the tree. From the fourth year, some sub branches can be pruned out at the union where they join the main branch, to allow new sub branches to take their place.
Once the fruit sets (starts to develop) around mid June, thin out the fruit on each branch so that they are not overcrowded. This allows the individual fruits to increase in size and helps to prevent branches snapping under the weight of a heavy crop. In a few months time you will be enjoying your own home grown fruit picked fresh from the tree.
Healthy Fruit Trees
It is essential that every fruit tree in your yard is suitable for the climate, soil and location in which it is placed. A great variety of fruit trees can be grown in Melbourne’s temperate climate, including bananas if they’re in a warm, protected spot.
- Most fruit trees prefer a full day’s sun (or close to it) throughout spring, summer and early autumn. Fruit will not ripen if it does not receive enough sunlight. Evergreens such as feijoas, citrus and loquats need winter sun too.
- Most fruit trees prefer to be in a wind-protected spot, and a spot where they will not be effected by frost in early spring.
- Fruit trees do not like to compete with grasses in their root-zone. Mulch or ground-cover plants should be placed beneath fruit trees. Alternatively, you can use chickens to keep the grass down.
- In their establishing years for survival, and in later years for maximum fruit production, fruit trees will require regular watering, particularly in spring and summer.
- All fallen fruit must be quickly picked up and either used or composted. This is to prevent pest insects from building up. Alternatively, if you have chickens, let chickens run beneath your fruit trees to eat the fallen fruit and convert them to a great fertiliser.
- Most fruit trees do not like heavy clay soils, as they do not drain well and can cause roots to rot. Before planting, mix compost through the soil in and around the planting hole. Build up a mound of loose friable free draining soil (once again including lots of compost) in which to plant the fruit tree. It helps to shape the mound like a volcano with a crater in the middle so water doesn’t run off. In some cases digging in drainage trenches filled with gravel is a good idea.
- Very sandy soils are also problematic, as they hold less moisture and nutrients for the trees. Once again solutions can be found in good compost. Dig a deep hole and mix compost through the soil below and around your new plant. Mulch heavily. You’ll need to water more regularly, but once established your fruit trees will do fine.
- Lavender and rosemary shrubs, and a range of daisies are great to plant near fruit trees to attract pollinating bees and other good insects, while deterring pest insects. Warrigal greens (also known as native spinach) can form an edible, grass suppressing ground cover, and comfrey is a top-notch nutrient cycler we use extensively. Alpine strawberries and violets are a couple of hardy and edible groundcovers that can suppress weeds.
- For that shady spot in your yard, currants and tamarillo will still supply fruit if placed in a partially shaded position. Among fruit trees apples and plums are more shade tolerant than most.
Deciduous Fruit Trees
Deciduous trees are ones that grow and fruit in spring and summer, drop their leaves in autumn, and are bare in Winter. Such fruit trees include apples, plums, nectarines, peaches, grapes and pears. Generally, deciduous fruit trees:
- are best planted in mid-winter while they are dormant. You can buy them cheaply as ‘bare-rooted’ trees at this time, and more varieties are available.
- are available as dwarf trees, reaching only 3m in height – great for small backyards. Dwarf trees can be grown in a large pot if they are pruned well. With spring-summer pruning you can keep any tree to dwarf size though.
- do not need to be fertilised or watered between mid-autumn and mid-winter – they are asleep in these months. Fertilise in late winter.
- you’ll have to prune to contain or shape the tree, and to stimulate new fruiting growth. While traditionally fruit trees were pruned in late winter while dormant, this stimulates growth in the growing season whereas spring-summer pruning can be useful for keeping trees to a desired height. Some useful books on pruning include Pruning: A Practical Guide by Rodger Elliot (1993), The Pruning Handbook by Steve Bradley (1996) and the CSIRO publication Pruning for Fruit and Flowers by Jane Varkulevicius. You can also hire the VEG team to prune your fruit trees and mentor you.
- are often grown in a vase shape (with inward facing branches removed), so that all branches receive a good amount of sunlight, and do not rub against each other. This is especially true of stonefruit.
- can be grown rather flat along horizontal wires (eg. along a fence or a wall) – this is called espaliering. See The Australian Fruit and Vegetable Garden by Clive Blazey and Jane Varkulevicius, published by The Diggers Club, 2006.
- may require a cross-pollinating tree to be planted nearby (read the label and ask at the nursery.)
- There’s an approach to backyard orchards called Backyard Orchard Culture. Read an excellent article about it here. A central idea we use in many of our orchards is multiplanting (up to four fruit trees in the same hole as an alternative to multi-grafted trees). This can be useful for getting a range of fruit from a small space and for getting cross-pollinating varieties in a small space.
This includes lemons, oranges, lime and mandarins. Generally, citrus trees:
- will fruit all year round, or for extended periods.
- need to be placed in a sunny spot, where they will also receive winter sun.
- like to be fertilised in late winter. Citrus trees are heavy feeders so fertilise well, and fertilise more often if the tree is looking stressed.
- should be kept to around 2.5m across for maximum productivity – they do not produce fruit in the center of the tree
- prefer a soil with good drainage – slightly sandy is ideal, and if you are on clay soil, you need lots of organic matter.
If you have a warm frost free area (for instance along a north facing wall with good winter sun) you can grow various bananas and other subtropical fruit such as babacos (a type of papaya), cherry guavas and a range of other plants like taro, lemongrass and galangal. These plants are shallow rooted and like lots of water, nutrients and compost!
Need a Hand?
This is a five-year old orchard we designed in Melbourne’s Eastern Suburbs.
Growing Citrus Trees
It’s almost mandatory to grow a citrus in the Australian backyard, especially a lemon. No citrus fruit purchased at a supermarket has the same flavour as one picked, peeled and eaten in the backyard and with such diversity in size and varieties there is a citrus tree to suit any garden, backyard or balcony.
Citrus have many more benefits than just the delicious, brightly coloured fruit. They produce the most glorious perfumed flowers and are covered with glossy, green leaves that make these terrific feature trees in the landscape or eye-catching informal hedges.
Citrus are best where the days are long and sunny and do not thrive in frost prone areas. They are quite demanding when it comes to soil quality and are very hungry and thirsty. Be sure to regularly add slow release fertiliser to those in pots and don’t allow them to dry out.
All citrus grow very well in large tubs but in recent years new dwarf varieties that still produce masses of full sized fruit make growing citrus on patios and balconies very easy indeed. Choose as large a container as possible, use premium potting mix and ensure that it is in a bright, sunny position.
Citrus are best planted in an open, sunny aspect where they will not have to compete with established trees and lawns and are protected from strong winds.
When planting, dig as large a hole as possible. Mix a combination of compost and dynamic lifter with the soil in the bottom of the hole. On top of this put a layer of soil without fertiliser which will help stop the young roots from burning.
Buying younger trees is often more successful than older trees as their roots establish more quickly and they need less pruning to form a balanced canopy.
Without disturbing the root ball on the new tree, place it in the hole making sure the roots don’t touch the fertiliser and that the graft union on the stem is well above ground level. Firm the soil around the roots and water immediately with a seaweed solution.
If the tree is very large, it is a good idea to prune the top after planting to prevent leaf drop and poor development. If the top has many branches, cutting back to three main branches about 15 to 20cm long will help to develop a strong framework. Young citrus need some protection from the sun in the first few months after planting. Protect their trunks with tree guards or by loosely wrapping with shade cloth and mulch well to prevent moisture loss.
WATERING AND FERTILISING
Citrus have shallow feeder roots which concentrate under the trees canopy so keep the soil moist to a depth of at least 30 to 40cm. Citrus are very heavy feeders because they have rapid growth and bear enormous amounts of fruit. Commercial citrus fertilisers that contain trace elements should be applied during the growing season and then again in spring and when the fruit is setting.
If spraying weeds with glyphosate be very careful as even the slightest overspray can cause severe damage to citrus trees.
Adding compost or manure to the base of citrus trees regularly will help to reduce soil temperatures, reduce weeds and encourage earth worms. Hand weed around the trees being careful not to disturb the soil.
Citrus do not require annual pruning except to prevent the tree from becoming unbalanced. If three main branches are developed whilst the tree is still young, an open canopy will form and the tree will only need to be kept to a manageable height. On older trees, strong shoots that grow from the main branch should be shortened or removed so they don’t take over and dead wood and tangled limbs can be removed. Remove any shoots that develop on the trunk, especially those below the graft union.
PESTS AND DISEASES
Mediterranean fruit flies lay their eggs in the ripening fruit and the larvae feed on the flesh rendering it inedible. Mandarins are highly susceptible and lemons and grapefruit are hardly affected. Infested fruit must be destroyed to prevent the larvae from developing. The fly is attracted to the colour yellow so yellow sticky paper and fly traps hanging amongst the trees are very effective at trapping them.
Whitefly will suck sap from the tree as well and cause a sooty mould on the fruit which turns to sugary syrup. They swarm the trees and are obvious when the branches are disturbed. White oil will help control these pests but yellow sticky paper will also trap them and help control their numbers. Other pesticides are available that will assist.
Scale is not uncommon on the leaves and trunks of citrus. If there are just a few, they can be scraped off with a finger nail but where there are too many, spraying with White Oil or Pest Oil will suffocate the little insects that sit under the shell. Do not apply in the heat of the day however as the oil content will burn the leaves.
Aphid may appear on new growth and buds but are easily dealt with by using Confidor or other suitable insect sprays. With aphid, and in fact mealy bug and scale, ants are often present as they “farm” these insects to feed on the sugary nectar that they excrete. It is important to treat the ants as well as the insects otherwise the problem will not be resolved.
Citrus leafminer moths are rarely seen but their caterpillars leave a silvery trail through the centre of soft new leaves leaving them twisted and distorted. To reduce the population prune new leaves when leafminer numbers are highest and fertilise in winter to promote strong spring growth. Pest Oil is effective at controlling leafminers but don’t apply in the heat of the day.
- Collar Rot girdles the trees trunk. Do not allow mulch to pile up against the stem or the soil to build up above the graft union. Anti-rot products will assist where damage has already occurred and good air flow is essential.
- Root Rot attacks and kills the roots of trees. Anti-rot products are safe and available to treat the tree.
- Fruit Rot is caused by blue and green moulds on fruit hanging within the tree canopy. Provide more light, check for insects and destroy fruit immediately.
- Young fruit dropping from the tree or sunburn on the fruit is probably caused from excessive heat and harsh sun. Don’t allow the soil around the tree to dry out and consider covering the tree with shadecloth until the weather cools.
JOBS THROUGH THE SEASONS
SUMMER December – February
- Prune the trees once all the fruit is picked.
- Water well throughout summer.
- Thin the fruit if the tree is too heavily loaded.
- Fertilise a little.
AUTUMN March – May
- Some mandarin are ready for picking.
- Plant new trees whilst soil is still warm.
- Fruit changes from green to orange.
- Put up fresh yellow sticky traps.
- Continue watering & lightly fertilising.
WINTER June – August
- Most varieties are picked throughout winter.
- Control weeds so they don’t steal nutrients.
- Fertilise a little.
SPRING September – November
- Fertilise very well in spring.
- Prune in late November through December.
- Fruit begins to set in early spring.
- Control weeds and insects.