When to transplant trees?

As a landscaper I have to transplant trees and shrubs all year round. Working with more mature plants is a great way to make a new garden look established, not to mention the money you save by not buying large trees and shrubs. Now is the time to move plants around the garden.

Even the best designed gardens sometimes need a tweak or you may inherit a valuable plant from a friend or family. Transplanting is an important skill that saves money and helps create the garden you want.

The biggest problem with transplanting occurs when the plant being moved goes into shock. Whether it is moving a metre, or from one house to another, the same rules apply.

How to transplant a shrub. Photo: domain.com.au

Get the biggest root ball you can manage. Try to keep as much soil attached to it as possible. Have it out of the ground for the least amount of time and don’t let it dry out. Here are the finer points that will help your plant survive the stress and increase the chance of success.

The first thing to consider is the new location. The right spot will have the correct light, soil conditions and drainage. Is there space for the tree or shrub to grow correctly or will you have to move it again in a year or two?

My most important tip is to dig the new hole before removing the plant. If you run into trouble with rock, pipes or builders’ rubble, at least you’ll have time to solve the problem. This minimises the time the plant is out of the ground and reduces the chance of the roots drying out. Dig your hole twice the width of the root ball. You can get an idea of how big the rootball is by digging your spade around the drip line of the plant. You don’t need to dig your hole deeper than the root ball as this may cause problems with sinking or puddling and potential root rot.

When it comes to digging out the plant, use a long-handled spade and dig straight down. You will feel the roots and get a feel for the size of the root system. If its root ball is larger than the spade it is a good idea to have a helper for the final movement from the garden bed to a pot or barrow.

Before you replant, have a good look at the root system and clean up any damaged roots with secateurs or loppers.

I like to place the plant in its new home, level it and make sure its best face is pointing in the right direction. I usually back fill with the existing soil and mix in about a third of compost to improve the soil.

As I back fill, I like to use the hose to move the soil around as it’s gentler than your hand or your heel. I like to mound soil around the root system the same width as the hole to work as a well or dam for the first couple of months. This can be levelled off or removed later but it allows for deep, slow watering.

Unless you have extremely cold weather, late winter and early spring are the best times for transplanting. Warm weather and strong winds are your enemy so, if your garden needs a mini makeover, now is a great time to transform it by transplanting.

Autumn is the season for moving plants

When it comes to larger trees and shrubs, you’ll be limited by the weight you can lift. A root ball one metre across can be surprisingly heavy and it may require at least four people to lift it. If the root ball is larger than you can physically handle, you’ll have to cut the roots back to a manageable size, which could cause irreparable damage. In this case it may be better to consult an expert arborist for advice.

Despite these qualifications, there are many things you can do to improve your chances of success at transplanting time, including:

  • Prepare the new position well beforehand. Preparing the soil beforehand will help new plants establish. Mix some Yates Dynamic Lifter Soil Improver & Plant Fertiliser into the bottom of the planting hole, which both improves the soil and provides plants with gentle slow release nutrients.
  • If the plant has a large root system and you can wait a couple of months before moving the plant, start by assessing the diameter of root ball you can handle. Then use a sharp spade to cut vertically down into the soil around this circle. Push the spade in as deeply as possible. This will encourage new roots to grow inside this area during the coming weeks.
  • Spray the foliage of the plant with Yates DroughtShield to minimise water loss from the leaves.
  • Choose a cool day to move the plant. Water the root ball and the new planting spot and allow both to drain.
  • Move with care, digging to extract the root ball with minimal disturbance. Wrap with plastic sheet or hessian to hold the root ball together.
  • Position plant in its new spot so it has the same aspect as before – and don’t plant more deeply.
  • Backfill gently and water to settle soil around the roots.
  • Apply some Yates Waterwise Soil Wetter to the root area to encourage water to move easily into the roots.
  • Trim any damaged shoots. Apart from this, these days most experts suggest it’s best not to cut back the foliage.
  • Make sure the root ball stays moist, especially in the vital first weeks.

Transplanting Shrubs

Autumn is a good time for transplanting evergreen shrubs and small trees as the weather is cooling down and the plants won’t get as stressed as they would in the heat of summer. The soil is warm, encouraging the roots to grow, and there is still some moisture in the air.

There can be many reasons why a shrub or small tree may need to be moved. It can be in a position that doesn’t suit it causing its growth to be stunted and it not to thrive. It may be shading other plants, the lawn or areas of the home where full sun is needed or perhaps it just doesn’t suit the design of the garden.

Whilst autumn is the time for transplanting evergreens, deciduous trees and shrubs should not be moved until winter when they are dormant as moving them at other times of the year may cause their roots to rot.

Mature shrubs and trees can be very expensive to purchase from a garden centre so it is worth trying to save and transplant one that already exists in the garden. But, it will take some time, plenty of thought and probably a few muscles from friends and family.

PREPARATION
Like most jobs around the house, transplanting is all about preparation. Preparing the tree, deciding on a location and having the right tools ready will make the job a whole lot easier.

The success of transplanting often comes down to the health of the tree and shrub. If it is already showing signs of stress, it may be the last straw for it to be moved and it might not survive. Of course, if it is not surviving in its current spot, it is probably worth risking the move as chances are that it will be lost anyway.

However, to increase the success rate, start building up the plant’s strength several weeks ahead by applying weekly applications of seaweed extract over the leaves, trunk and soil around the roots. Seaweed extract helps to thicken the cell walls of the plant so that it can withstand the stress of moving much better. This can also be applied at transplanting and then weekly afterwards as it also encourages root growth. It is not a nitrogen-rich fertiliser so will not cause an unwanted flush of leaves.

The new location of the shrub is a really important factor, not least because you won’t want to move it again if you make a bad choice. Consider the requirements of the plant first and, if unsure, take a stem down to your local Better Pets and Gardens to ask for advice. Then, find an area of the garden that will suit the plant as well as the need of the family. Consider the direction of the sun at all times of the day, including the shadow that the newly moved shrub or tree itself will cast on other plants in the garden. Also make sure that the amount of water and the soil requirements of the new plant suites the others in that zone so that watering and fertilising is easy to carry out.

Prepare the new hole early. Don’t add fertilisers to the hole as the increased supply of nitrogen from this might burn the new roots and will encourage new leaf growth which will stress the plant. The aim is to get the roots of the tree or shrub to establish before new leaves are formed. Add a few shovel loads of sheep manure to the hole instead as this is low in nitrogen. Then, once the plant is in the hole, an application of slow release fertiliser can be sprinkled over the top.

Make the hole twice as wide as the root ball is expected to be. This is hard to judge at this stage but it is important to break up the area around where the roots end up so that they can grow easily into it. Keep the base of the hole solid however to give a good foundation to the root ball and prevent it sinking.

It’s worth investing in a bottle of spray-on leaf polymer which is available at Better Pets and Gardens. This innovative product puts a protective film over the leaves and stretches as they grow, lasting up to 90 days. It protects the plant from water loss, reduces water usage by up to 50% and increases the survival of plants being transplanted. This means that even though the roots have been cut and aren’t taking up as much water, the plant itself won’t be losing much either and so should cope until the roots start to do their job again. This product comes in a trigger pack and can be applied several hours before the move.

MAKING THE MOVE
Prune the tree of water shoots and then dig a ditch around the tree and use this to give the roots a good soak. Make sure that the water has gotten right down into the soil as this will help prevent transplant shock.

When the soil is saturated, the main roots can be exposed so that they can be cut. This is where the friends with muscles and sharpened shovels come in as this can be hard work. Don’t cut the roots too close to the trunk but the size of the final root ball will depend on the species being moved. You will soon be able to work out where the bulk of it is. Once the side roots have been cut, use the shovel to slide in underneath to cut any deeper roots. The idea is to keep as much of the root ball intact as possible but if the soil is sandy, this will soon fall off in the moving process anyway.

Before removing the shrub or tree from the hole, mark the side of it that faces north. This will help you orient the shrub so that it faces a similar direction later to prevent sunburn from the harsh northern sun on the softer, south facing leaves or trunk.

Once the root ball is separated from the soil, move the tree or shrub onto a tarp to make transporting easier. Use the tarp to drag the tree to the new hole and gently ease it in. Spend some time positioning it carefully making sure that it is facing the correct way and that the trunk is straight. If you get it wrong at this stage there will not be an opportunity to correct it later. Aim to have the top of the root ball level with the top of the soil in the new position.

Shovel the excavated soil back into the hole, gently tamping it down and watering it as you go. This will eliminate air pockets which could cause the plant to shift later on. Mound up more soil in a ring around the newly planted tree as this will act like a basin, catching the water and ensuring that it goes to the recovering root ball.

AFTER CARE
Mulch is essential for a newly transplanted tree. Spread a 10cm layer both inside and outside the tree, making sure that it doesn’t touch the trunk and then add that application of controlled release fertiliser. Applying a soil wetting agent is also a great idea at this stage to ensure that the water gets down to the roots through our hydrophobic WA soil.

Then, water, water and more water until the shrub or tree is established adding some seaweed extract to the bucket every week or so. After four to six weeks the amount of water provided can be reduced but if the roots are allowed to dry out, the plant will die and all of your hard work will be lost.

Transplanting a tree or shrub is not always easy work but as hard as it is on you, it is probably even harder on the plant. But, once it recovers from the transplant shock, it should offer many more years of pleasure which certainly makes all of your efforts worthwhile.

6. Wait out winter. Ornamental grasses are best left until spring. Earlier flowering grasses (calamagrostis, deschmapsia, molinia) can be moved or divided in early spring while later grasses (including miscanthus and pennisetum) should be transplanted in late spring.

7. Forks are your friends. If you are dividing large root balls, lift plants with a fork and then prize the roots apart with back-to-back forks.

How to Divide Perennials

Above: At Coton Manor in England, “the head of the plant nursery Caroline Tait uses a large knife for dividing tougher knots, for example the roots of Vernonia, shown here,” writes Kendra. Photograph by Kendra Wilson. For more, see Garden Visit: A Peek Inside the Potting Shed at Coton Manor.

8. Divide and multiply. Autumn, when the earth is still warm but also moist, is an ideal time to divide or move plants. Clump-forming herbaceous perennials including geraniums, sedums, phlox, asters, and hemerocallis all can be divided to make additional young plants. “You should be guided by the plant — ideally you want some good strong buds on top and some good strong roots,” says Ed.

Above: Sedums, ready for a new home. Photograph by Kendra Wilson.

9. Administer TLC. “It’s very rare that I divide and replant divisions straight into the garden, which makes me deeply unpopular with lots of students,” says Ed. “I’ll pot it up and get it growing before it goes back out into the garden. If you are dividing plants in the autumn they can sit in a greenhouse or cold frame over winter and then be planted out in spring.” This will not only mean that you can monitor your plants more closely, but will also protect them from wind or pests.

N.B.: Looking for more reasons to putter around in the garden before the weather gets too cold? See:

  • Garden Hacks: 10 Genius Ideas to Keep Plants Warm in Winter.
  • November To-Dos: 9 Ways to Winterize Patios (and Other Outdoor Rooms).
  • Expert Advice: 7 Tips to Put Your Garden to Bed for the Winter.

Finally, get more ideas on how to plant, grow, and care for various perennial plants with our Perennials: A Field Guide.

Additionally, get more ideas on how to plant, grow, and care for various shrubs and hedges with our Shrubs: A Field Guide.

Transplanting Trees and Shrubs

It happens to most homeowners at one point or another. You plant a tree in one location only to find out you need to move it a few years later. Perhaps you planted it a little too close to the house, and now you’re worried the branches will cause problems later down the line. Maybe you want to add on to your home and that tree or shrub is currently planted where the extension will be. Maybe the spot where you planted it is simply less than optimal for its growth due to sunlight, soil, or drainage problems. Whatever your reason for transplanting may be, you’re probably wondering how to do so without damaging the plant or impacting its future growth. Here are a few steps to help you get started and make the process less stressful for both you and the tree.

Plant at the Right Time of Year

Typically, the best time to transplant your tree is in the fall, when the leaves have already fallen from it. If you miss that window, late winter and early spring are also good times to transplant, as long as you move it before it begins to bud.

Get a Handle on the Project

Moving a mature tree is a no small undertaking. In addition to physically moving a large tree, you may have to prune its roots ahead of time, dig large planting holes, and provide comprehensive care for it after it’s been moved. It’s important to assess the project ahead of time to determine whether you can do it yourself or if you need to enlist the help of a professional.
How Large is the Tree or Shrub?

In general, shrubs that are three feet tall or less and trees that are about an inch in diameter don’t require you to dig up an entire root ball. For anything larger or older than about four years, you’ll have to keep the root ball intact. To be specific, you’ll need about a foot diameter of root ball for every inch of the trunk’s diameter. Keep in mind that the larger the root ball, the heavier the tree will be, so you may have to rent or borrow the right machinery to handle it.
Do You Have a New Spot Picked Out For It?

Before you start digging, make sure you have a new spot picked out for your tree or shrub. If you’re moving it to make way for new construction or to avoid future damage, choose a spot with similar conditions to where it’s already been planted. For example, if it was doing well in a sunny location with well-drained soil, find another spot on your property that mimics these conditions. If you’re moving the tree or shrub in hopes that it’ll become healthier, look for a spot with the best possible growing conditions for it. For example, if the spot it was in before was too windy, find a more sheltered place to plant it this time.
It’s important to note the locations of overhead/underground utilities as well as property lines when transplanting. Often, workmen from the utility company will come out and mark the location of underground power, phone, and cable lines as well as sewer and water mains if you call them. Dial 811 to contact your underground utility provider. If you’re unsure of the exact location of your property lines, your municipality may be able to help you.

Transfer Preparation

One of the first things you should do before transplanting a tree or shrub is prune its roots. Root pruning will allow the tree to absorb nutrients and water more effectively and efficiently. Basically, you want to encourage the plant to get a head start on growing roots it can take with it to its new home. Ideally, the best time to do this is during the spring before the transplant (assuming you plan to move it in the fall). However, if you can’t do this in the spring, do it in the fall, after the leaves have dropped. Then, transplant the tree in the early spring.
To prune the roots, begin by watering the soil thoroughly about 24 hours beforehand to soften the ground around the tree and make it easier to dig. Determine where you intend to prune, keeping in mind the general rule that for every inch of trunk diameter, you should have about a foot of root ball.
Cut a trench, ensuring that the spade you use has a sharp edge. Cut the roots using a lopper until you’re about two feet down. Once you’ve done this all around the tree or shrub, return the soil to the trench and give it a good drink of water.

Time to Transplant

It’s easier to transplant when the soil is soft, so give the area a thorough watering 24 hours before you plan to start digging. While it may be instinctive to lift the tree or shrub out of the ground first, it’s actually easier to dig the planting hole beforehand. Be sure to dig it at least two or three times wider than the root ball. Give the hole a good watering before transplanting as well — your tree or shrub is sure to be thirsty when it gets to its new home.
Remove topsoil from above the roots, and begin digging a few inches further out than where you dug the trench to prune them. Continue digging, being careful of the roots as you go. Once you’ve dug down to the right level, start digging under the root ball at about a 45-degree angle. It’s helpful to lay burlap next to the tree, so when you’ve freed the root ball from the ground, you can wrap it up and move it without the roots drying out too much. Be sure to keep the root ball moist, and if it’ll be a while before you can place the tree in its new spot, keep it in a shady area in the meantime. To preserve the integrity of your tree or shrub, always remember to lift by the root ball instead of pulling by the trunk.

Transplant TLC

Although the literal and figurative heavy lifting may be over, there’s still some work to be done after you’ve transplanted the tree. As with any kind of planting, water is important. Although the amount of water you should give your tree will depend on its size, soil type, and the weather, a deep watering every two weeks or so is essential, especially if your area doesn’t experience much rainfall. Keep the soil moist by placing a couple of inches of mulch around the tree’s base but away from the trunk.
To ensure that your tree or shrub stays straight, place stakes around it and support it using rope or line. Keep an eye on the plant’s growth, but be aware that it may take a year or two before it adjusts fully to its new spot.

How to Transplant Young and Small Trees

The process for transplanting young and small trees is essentially the same as that for transplanting mature ones but on a smaller scale. Since transplanting is stressful for the tree regardless of its age and size, you’ll always want to be careful. Like older, more mature trees and shrubs, young trees should be transplanted in the early spring or fall after their leaves have fallen.
Before you dig the tree up, make sure the soil around it is moist, which will make it much easier to remove and help keep its roots intact. Start watering the area a few days before you plan to dig. The root ball size guidelines are the same for young trees — about a foot for every inch of trunk diameter.
Dig a hole two to three times wider than the tree’s root ball and about an inch shorter than its height. Do this ahead of time so you can transplant the tree right away.
Use a spade to dig a one to two-foot trench around the tree, and then cut at a 45-degree angle under the roots. Again, place burlap next to the trench so you can tip the root ball onto it once you’ve pulled the tree up. You may notice that balls of soil cling to the roots, but don’t remove them — they will increase the tree or shrub’s chance of survival once it’s in its new spot. Always handle the tree by its root ball, and avoid grabbing it by its trunk.
Place the root ball into the planting hole and backfill the soil into the hole. Once it’s in place, water the tree or shrub thoroughly and place stakes around it to ensure it stays straight. Again, it’ll take a few years for it to adjust to its new home, so be sure to keep an eye out for any signs of stress.

Transplanting Trees And Shrubs: How And When To Move Trees In Landscape

Moving an established tree can be an intimidating project, but if it can transform your landscape or fix fundamental design problems, it’s worth the trouble. But how exactly does one go about moving trees? This article explains when and how to transplant a tree, so keep reading for some tree moving tips.

When to Move Trees

Move a deciduous tree in early spring before it begins to leaf out or early fall after the leaves begin to turn color. Don’t move evergreens during a growth flush or in the fall when it’s too late for them to become established before winter weather arrives. Late summer is usually a good time to move evergreens.

Tree and shrub roots extend well beyond the volume of soil that you will be able to move. Prune the roots to a manageable size well in advance so the cuts will have time to heal before transplanting trees and shrubs. If you plan to transplant in the spring, prune the roots in the fall, after the leaves drop. If you want to transplant in the fall, prune the roots in the spring before the leaf and flower buds begin to swell.

How to Transplant a Tree or Shrub

The volume of the root ball you’ll need to successfully transplant a tree or shrub depends on the diameter of the trunk for deciduous trees, the height of the shrub for deciduous shrubs, and the spread of the branches for evergreens. Here are the guidelines:

  • Give deciduous trees with a 1-inch trunk diameter a minimum root ball size of 18 inches wide and 14 inches deep. For a 2-inch diameter trunk, the root ball should be at least 28 inches wide and 19 inches deep.
  • Deciduous shrubs that are 18 inches tall need a root ball 10 inches wide and 8 inches deep. At 3 feet, allow a root ball of 14 inches wide and 11 inches deep. A 5-foot deciduous shrub needs a root ball 18 inches wide and 14 inches deep.
  • Evergreens with a branch spread of about a foot need a root ball 12 inches wide and 9 inches deep. Evergreens with a 3-foot spread need a root mass 16 inches wide and 12 inches deep. A 5-foot spread means that the plant needs a 22-inch diameter root ball that is at least 15 inches deep.

The mass of soil for trees greater than two inches in diameter weighs several hundred pounds. Moving trees this size is best left to professionals.

Prune the roots by digging a trench around the tree or shrub at the proper distance for the size. Cut through the roots as you find them. Refill the trench when you are done, adding water and pressing down firmly a couple of times to remove air pockets.

Here are some tree moving tips to help transplanting go as smoothly as possible:

  • Prepare the planting hole before digging up a tree. It should be about three times as wide and the same depth as the root ball. Keep the subsoil and topsoil separate.
  • Tie up the branches with twine or strips of burlap to keep them out of the way while moving the tree.
  • Mark the north side of the tree to make it easier to orient it in the right direction in the new location.
  • Trees are lighter and easier to handle if you rinse off the soil before moving the tree. You should only remove the soil from trees and shrub roots when the trunk diameter is greater than an inch, and only when moving dormant trees.
  • Set the tree in the hole so that the soil line on the tree is even with the surrounding soil. Planting it too deep leads to rot.
  • Fill in the hole, replacing the subsoil to the proper depth and finishing the hole with topsoil. Firm the soil with your foot as you fill, and add water to fill the hole when it is half full of soil to remove air pockets.
  • For the first few weeks, water often enough to keep the soil moist but not saturated. Two to 3 inches of mulch helps the soil retain moisture. Don’t allow the mulch to come in contact with the trunk of the tree.

How to Transplant a Tree: What to Do and What Not To Do

Trees root into the earth, but that doesn’t mean they are impossible to remove from the ground and transport to a new home.

You love your trees, but sometimes they’re better suited for locations elsewhere. Perhaps they’ve out-grown the space in which they’re rooted, or, maybe you plan to move somewhere new but wish to bring that special tree along with you.

Guidelines for Safe & Proper Transplanting of Trees

Regardless of the tree you’re moving and the space to which you plant transport it, there are several guidelines to follow for the safe and proper transplanting of trees:

When is the best time of year to transplant a tree?

There are good and not-so-ideal times of the year to transplant trees. “The best time to transplant a tree is when it’s dormant and the ground conditions are ‘just right,’” says Rick Hanshaw, manager of the Davey Nursery in Wooster, Ohio.

What Should I consider When Picking a New Home for a Tree?

Ideal transplanting locations depend on the size and species of the tree you transplant. According to Hanshaw, trees prefer different levels of shade and sun, as well as varying soil drainage conditions. The potential height and size of the tree and the location of home foundations, power lines and underground utilities all affect the transplanting location. “You need to identify the tree species first,” Hanshaw says. “There are a lot of different variables involved with choosing the correct location to which to transplant a tree.”

Transplanting Mature Trees vs. Young Trees

There isn’t a big difference between transplanting mature trees vs. young trees. The vigorous growth rate and easily manageable root ball of a young tree make its transplanting process fairly easy. However, all trees experience some degree of shock after being transplanted—the length of recovery time simply depends on the quality of aftercare. “Mature trees will just take more aftercare than younger trees after being transplanted,” Hanshaw says.

Can All Trees Be Transplanted?

Some tree species react better to transplanting than others. According to Hanshaw, red maples, elms, and bald cypress generally respond better to being transplanted than other species, in northern regions, in particular. “Specifically red maples have much more fibrous root systems of which you can capture more when digging,” Hanshaw explains.

Most trees will move well, assuming proper time is allotted to correctly fertilize, root prune, dig the properly sized root ball and water before and after transplanting. It is equally important to continue a pest management/fertilization program after transplanting, as the tree can have a 1- to 2-year root transition growth before becoming reestablished.

The only conditions for which we do not recommend relocating a tree include:

  • The tree is in a state of stress/deterioration that would warrant a removal
  • The new location is unsuitable for the specified tree.

Set Yourself Up for Successful Replanting

  • Ensure the time and budget required to transplant a tree in a careful, timely manner is available.
  • Your tree will lose a significant amount of its root system during transplanting. Make sure it’s well-hydrated before the transplanting process begins.
  • Once the tree is uprooted, tie up the crown as much as possible to reduce limb breakage during the move.
  • Wrap the tree in a tarp to reduce wind damage and moisture loss.
  • Water the tree as soon as possible after transplanting. This is the most important.
  • Follow up with proper tree care and inspections for insect damage.

What is the establishment period and how long is it. In broad terms by the end of the establishment period a tree should have regenerated enough roots to keep it alive without additional irrigation.

The establishment period can last from 3 months to 3 years depending on size and when planted. Trees will establish quicker in warmer climates than cooler. All trees need regular irrigation during establishment; the amount depends on climate with temperature and rainfall being the main influences. Adequate irrigation promotes quick establishment by encouraging rapid root growth into the landscape soil. (Harris and Gilman 1993).
To determine if a plant is fully established compare growth rates before and after transplanting. Growth rate will slow immediately after transplanting and recover to pre-transplanting levels as the root system regenerates and post planting stress is reduced.
After planting, water is usually the most limiting factor. Even if soil moisture is adequate, the root system may not be able to absorb water fast enough to completely satisfy the needs of the plant. Temperature, light, nutrients, and other factors are usually less limiting than water for the initial period after planting. It is very important to make sure the root ball moisture levels are correct as the tree relies heavily on this during the first growing season.
This is why it is very important to plant into non compacted, aerated soil to encourage roots to elongate and to extend out into a larger soil volume as quickly as possible. So therefore it is essential that the trees you purchase have a well develop root system and we believe at Mt William Advanced Tree Nursery the best way of doing this is by purchasing a tree in an air pruned containers (Rocket Pot®), or from a container treated with Spin out ®.

Irrigation of Newly Planted Trees
When newly planted trees die, blame is often placed on bad plants, insects or disease. However more plants die from being planted too deep, too much or too little water, poor drainage, inadequate preparation of the planting site and no on going maintenance program to ensure proper establishment and long term survival. The irrigation system that is selected should be separate from any other system and be specific for trees. This can range from watering by hose from tankers or mains or a low volume irrigation system. What ever system is used regular monitoring is required so the correct amount can be given. Systems designed for garden beds or lawns can lead to over and under watering. For example trees planted into lawns that are irrigated regularly can cause over watering as a lot of this water runs over the soil surface and collects in the loose soil of the planting hole. Root balls of trees can dry out several hours to one day after irrigation (Nelms and Spomer 1983). The root ball has to be watered when it dries out, even when the surrounding soil is moist, because water will not move from the surrounding soil into the root ball unless the soil is saturated. Trees cannot use this moisture outside the root ball until the roots grow into the back fill.

Frequency of Irrigation
There has been a lot written on the amount and frequency of water required for newly transplanted trees. It is difficult to follow these recommendations as there are many variables that can affect the transpiration rate which in turn determines the amount of water and frequency required. You must familiarise yourself with the characteristics of your planting site, each situation is different.
You need to consider:
• Temperature
• Rainfall
• Wind
• Humidity
• Amount of cloud cover
• Soil Drainage
• Compacted Soil
• Soil texture of root ball
• Time of year
• Size of tree being planted
• Transpiration rate
• Evaporation rate
Then make any physical changes to the planting site before planting to provide the best environment possible for the successful establishment of the newly planted tree.
There are many guides and formulas (Gilman 1997, K. Handreck and N. Black 1984, R. Harris, J. Clark and N. Matheny 1999.) used to determine how much water a tree needs after planting but these are a guide only and no two sites are the same and I cannot emphasise enough that you must evaluate the planting site, understand the conditions you are working in and consider the weather conditions because these factors will determine how often and how much.
Generally speaking over watering is the major reason for trees dying; under watering will not necessarily kill the tree but retard critical root development outside the root ball, essential for successful establishment.
Moisture needs to be available in the soil for the tree at all times as transpiration is taking place, not just when you decide to water. The irrigation needs to be matched to the weather conditions and the stage of growth.

Trunk Diameter Watering Requirements Approx. Irrigation Volume
50mm Daily for 2-4 weeks; every other day for 2 months; weekly until established. 11-23 litres
100mm+ Daily for 2 months; every other day for 5 months; weekly until established. 45 litres

(Adapted from Gilman 1997)
The above chart is based on weather conditions not dissimilar to South Eastern Australia but does not take into account weather conditions, time of year and drainage rates from soil. The assumption here is that trees are planted into well drained sites. Remember that minimum irrigation to keep trees alive eliminates daily irrigation, and could be extended to once a week. Other “experts” suggest weekly amounts for example 4 litres of water per week per 25mm trunk diameter. Therefore if you purchase trees from Mt William in the following containers this would a guide to the amount of water required.

Container Size Tree Height Trunk Diameter Approx. Irrigation per week
33cm 1.3-2m 25mm 4 litres
40cm 2.1-2.8m 30-45m 5-8 litres
60cm 3-4m 50-75mm 9-12 litres

Other methods used are by using formulas to determine tree water use and the potential volume of water stored and available in the root system for use by the tree. For the home gardener these can get very complicated and confusing. Just as these two charts show the opinion on the amount and frequency can vary enormously.

As per our planting guide the best practice to determine frequency is to do physical checks by digging down the side of the root ball or using a probe to try and determine moisture levels and take into account all points mentioned previously. If the soil in the back fill crumbles and falls out of your hand as you open your figures, increase the volume of irrigation. If soil stays together as you open your fingers moisture in the back fill is probably ok. If water drips out between your fingers reduce the volume of water that is being applied. It is very important to check the root ball as this may be dry.

Left hand drawing shows dry soil falling from hand. End drawing showing the extreme with water dripping from hand. Middle hand shows soil holding together due to correct moisture.

Placement of Irrigation
Apply water directly to the root ball, because that is where the roots are located at planting. If watering by hand make sure a berm of soil is placed around the edge of root ball to hold the water (See Mt William Planting Guide) above the root ball so the water can soak into the root ball. As the root system develops and spreads, the berm will need to be made wider.
If using micro sprays or drippers make sure they are located over the root ball, as well as the surrounding soil. Remembering that the area over the root ball, may need more water initially than the surrounding soil.
Irrigation systems selected should have the capacity that has roots spread into the surrounding soil these areas can be irrigated. If the surrounding soil is not irrigated you will not get adequate root elongation into the surrounding soil volume. This is very important because as the root system expands it has access to the increasing volume of water that is available in the surrounding soil.
Shows dripper system covering all of the root plate and allows the expansion of the system as roots develop. This also allows for good penetration of water to the root system.
The irrigation system selected needs to be able to deliver slow deep amounts of water. This will help prevent run off and deep so that the soil volume where a large amount of the roots are located is watered and not just the top layer of soil.
Following Mt William Advanced Tree Nursery Planting Guide and guide lines set out in relation to establishing trees should ensure success. Keeping in mind planting at the correct depth into well aerated soil, maintain adequate soil moisture by watering effectively and eliminating competition by mulching to control weeds.

References: Gilman, E 1997, Trees for Urban and Suburban Landscapes. Handreck, K and Black, N 2001, Growing media for ornamental plants and turf. Harris, R and Clark, J and Matheny, N 1999.Arboriculture Integrated Management of Landscape Trees, Shrubs, and Vines. Lloyd, J Coordinating Author 1997, Plant Health Care for Woody Ornamentals.

Yes, you can.

But… only if it’s been outside since fall.

It’s because of something called “hardening off.”

Basically, perennial plants which can survive winter, such as trees and shrubs, have to develop a resistance to the cold before they can handle being outside in full, frosty winter weather.

This takes time, as you can imagine.

The quickest way would be to bring your perennials outside for a few hours per day, so that over time they get exposed to the cold enough to enter their dormant state. Over time, gradually leave them outside for longer and longer until eventually you’re leaving them outside all day.

Choose the mildest days you can though. Too much too soon can cause transplant shock to the plant, which is the exact thing you’re trying to avoid by exposing it gently over time.

After a few weeks, your plants will clearly look different. That’s when they’re ready to take the frost. They’ll look “wintery,” like all the natural plants you see around outside during winter.

If your winters are particularly harsh where you live, or if your plants have been indoors in a nice, warm environment, you’re going to want to give your plants more time to adjust. As a rule of thumb, the greater the difference in environment that you’re trying to adjust your plants to, the more gradual the hardening off process has to be.

What About If They Haven’t Been Indoors?

Then you’ll be completely fine. Just make sure to reduce transplant shock as much as possible. I’ll give the same advice here as I’ve given before: do whatever you can to protect the roots.

You see, the single biggest cause of transplant shock is overly-dry roots. Sure, you could try to keep your newly transplanted perennials as well-watered as possible in order to keep the roots moist, but all that water will simply cause even more damage to the root structure when it freezes.

Your best option is to surround your trees and shrubs with at least 5-6 inches of wood chips. They’ll lock moisture into the soil, so that you won’t need to water them any more after that, but they’ll also protect the roots from the cold. It’s the easiest way to ensure that your plants come out of winter happy, healthy, and ready to flourish in the upcoming growing season.

The Best Time for Transplanting Trees

It is very important when transplanting trees to be aware of the season. Trees lose most of their water through their leaves. So you should move these trees when they do not have leaves. In other words, the best time is while the tree is dormant. Another timing factor to consider is how old the tree is. Tree saplings over 6 inches would be a good choice, but remember the bigger the tree is, the bigger the root system it has, so more mature trees are going to be much harder to move, and have a greater chance of going into shock.

Late Winter

If you are going to move a tree in the late winter, make sure that you move it late enough that the ground is no longer frozen. Oak trees are one type of tree that does very well with late winter transplanting.

Early Spring

Moving and transplanting in the springtime is by far the best time to transplant trees. They will handle the shock so much better if moved correctly. The tree will still be dormant, and once you transplant it, then it will have perfect temperatures and rains to help it along.

Early Fall

Some trees fair fine if you transplant them in early fall, one type that prefers this time is the evergreen tree. If you are going to be moving evergreens in the fall, be sure to give yourself enough time so that your tree will be able to spend at least three weeks in its new home before winter starts. This method works best if your evergreen was shipped from an area that is colder than yours. If you live in a very cold area and your evergreen is coming from a warmer one, then you will want to wait to transplant this tree in early spring and let it have more time in the soil before winter hits it.

Summer

You will not want to, under any circumstances, transplant a tree in the middle of the summer. The tree will have all of its leaves so it will lose a great amount of water, and the weather is far too hot. Your tree will most likely go into shock and die, and then you will be missing out on its beauty.

Extra Tips

Now that you are ready to transplant your tree, here are a few other tips. Make sure the soil where you are going to be placing your tree is dug prior to moving your tree. Follow the correct procedure for digging up your specific tree. Keep your tree well-watered during the process of moving it. It may take up to a year for a tree to recover from being transplanted. The larger trees go into shock easier than the smaller trees during transplanting.

February is Our Time to Plant and Transplant

Punxsutawny Phil, the famous groundhog, said we’re in for six more weeks of winter. Of course, Phil’s a rather dim bulb, but because he’s just a groundhog, he doesn’t know this. Spring in the South starts in February, not March (or May in Moscow), and people here are itching to get outside and start planting. I know this because of two particular questions I’ve been receiving lately.

Question 1: “We have some large bushes that have gotten too big for the spot they’re in. Can we transplant them now or do we have to wait until after our last frost?”
Grumpy’s Always Correct Answer: As long as your soil isn’t frozen (and where in the South would that be?), you can transplant deciduous and evergreen shrubs and trees now. It’s an excellent time, because they’re dormant and won’t suffer the transplanting shock they would if they were already growing in warmer weather. No need to wait until after the last frost. The sooner you transplant, the better. Try to get as big a root ball with each plant as you can, plant it at the same depth it was previously growing, water thoroughly, and then mulch.

Question 2: “Is it too early to plant new trees and shrubs?
Grumpy’s Always Correct Answer: Absolutely not! It’s a great time! Even if the tops of the plants are still dormant, the roots are growing. By putting plants in the ground now, the roots get a head start growing into the surrounding soil before new foliage and warm weather put demands on them. All things being equal, the right tree or shrub planted in February has a big advantage over one planted in April or May. Dust off your shovel and get planting!

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