The Downey Trees blog is often upbeat and entertaining; this is not such a post. So often we are called out to look at Leyland Cypress trees that are having problems, and we know what we are going to find in most cases before we get there. Sharing the bad news is the worst part, but before we go there, let’s talk for just a minute about how we got here.
The Leyland Cypress (Cupressocyparis leylandii) was developed in England in 1888. The tree is a hybrid of the Monterey Cypress (Cupressus macrocarpa) and the Alaska or Nootka Cypress (Cupressus nootkatensis). The natural range of these 2 native North American plants is separated by 400 miles, but both plants were growing in close proximity at the Leighton Hall Estate, at one time owned by a Liverpool banker by name of Christopher Leyland. The genus Cupressocyparis arises from some controversy over the generic origin of the Nootka Cypress as some taxonomists classify it under the genus Chamaecyparis. That would imply that the Leyland Cypress is bigeneric cross, a very rare occurrence in conifers.
The modern popularity and widespread use of the plant began in the 1950’s, and by the 1980’s use of the Leyland Cypress was widespread. It is fast-growing, evergreen, strikingly beautiful in form and color, and adaptable to many situations. Like so many plants introduced before and since that are touted as the “perfect landscape plant,” the Leyland Cypress has fallen from grace. In the 1960’s, that perfect plant was the Red Tip Photinia. In the 1970’s, it was the Bradford Pear. So the Leyland Cypress was planted – everywhere! For decades it became one of the go-to plants for hedges, screens and specimens, and is still planted for these purposes. Despite the fact that the tree can grow 20 feet wide and 70-100 feet tall, many became hedges with a planted spacing of 5 feet or less. The trees grow quickly and provide privacy for individual homes on increasingly smaller lots.
Then the problems started. Being a cone-bearing plant with a Mediterranean cross Northern Temperate Cloud Forest heritage,the Leyland Cypress prefers moderate temperatures and soils that are airy and drain quickly, and on the moist side but never saturated and never bone-dry. Georgia conditions are precisely counter to this. Our air is damp with humidity, our high clay-content soils hold water, drain poorly, and exclude oxygen from the pore spaces in the soil. Not only that, while Georgia normally gets a robust 48-52 inches of rainfall per year, the distribution is anything but even: during the late summer and fall of 2016, we went well over 3 months with no rainfall whatsoever. Conversely, as of September 30, 2018 we have had 46.18 inches of rainfall – nearly 8 inches above average for this time of year. These contrary conditions and vast swings in soil moisture, coupled with the fact that the plant’s popularity has rendered it nearly a monoculture in close urban plantings, has made these plants susceptible to disease issues. Add to this the specter of broken branches from winter ice and summer thunderstorms, the diseases can spread rapidly.
There are 2 primary fungal pathogens that attack Leyland Cypress trees in the Southeast, Seiridium Canker and Botryosphaera (Bot) Canker. The symptoms of both of these fungal pathogens are the yellowing or browning of the foliage on one or many of the top or lateral branches. This telltale “dieback” is what we have all become so painfully familiar with. A closer look at the branches and main stem may reveal beads or runny areas of amber-colored sap oozing from the wood (Seiridium) or cankers, sunken areas girdling the base of dead shoots or branches (Bot canker). Unfortunately, there are no effective chemical treatments for the management of these diseases. While the spread of these fungi cannot be stopped, it can be slowed through some of the following management practices:
Planning & Planting
- When considering hedges and screens, think about using a variety of plants as opposed to a monocultural planting of Leyland Cypress trees or other conifers (yes, these diseases and issues are associated with other conifers such as Italian Cypress). When screening unpleasant views, a single plant is often all that is needed. A solitary Leyland Cypress has a much better chance of growing with a minimum of problems due to better light, air movement, and lack of similar plants in close proximity.
- Thoroughly amend the soil when planting to improve our common clay soil. Leyland Cypress trees are shallow rooted. Positive drainage is a must! Downey Trees has several products to improve drainage and poor soils.
- Provide adequate spacing between plants. Given the fact that the trees can grow 10-20 feet wide, planting them too close is a recipe for disaster!
- Provide plenty of water during the establishment period of new plants, and develop a plan to provide supplemental water during dry periods. It is a common misconception that conifers such as Leyland Cypress trees are tolerant of extreme drought. This is not the case!
Management of Existing Trees
- Avoid over-fertilization of plants – This often produces lush growth that is more susceptible to disease.
- Facilitate watering during dry periods – There is not much that can be done for established plants when we receive too much rain, but the wild wet/dry fluctuations of natural rainfall predispose Leyland Cypress to disease. Try to manage water to 1 inch per week (natural rainfall plus supplemental watering).
- Prune dead branches (either those shaded or those diseased) and sterilize pruning tools between cuts. Here are three ways to do this:
- A 10% chlorine bleach solution (1 cup bleach to 9 cups water). Note that chlorine bleach can corrode pruning tools.
- Full-strength Lysol – This seems to be the preferred method for maximum sterilization with minimum corrosion.
- Alcohol wipes – No drying required and may be a bit less cumbersome in the field.
- In situations where the height of the screening plants is valued, such as the case of the second-story deck in the photograph, it may be acceptable for the plants in a screening row to be more open at the base through elevation of the lower branches. Anything that can be done to promote light penetration and air movement within the canopy can prolong the life and health of the trees.
- Soil decompaction and sub-surface nutrient injections – Downey Trees can provide these two services to help maintain the health of existing Leyland Cypress trees or help slow the spread of Seiridium and Bot Canker in trees that are diseased. De-compaction aids water penetration during dry periods and drainage during wetter times. Nutrients enhance plant health by improving the living soil web as opposed to adding a high level of growth-stimulating fertilizers.
- Other diseases such as Cercospora needle blight also adversely affect the health and appearance of the trees. The photo showing Leyland Cypress Trees with browning foliage at the base of the plants is representative of Cercospora. While fungicides are effective against some of these other pathogens, repeated applications are often needed, and failure to apply the other management practices often results in a recurrence of the disease.
- The best expectation from enhanced management of Leyland Cypress utilizing the suggestions above is a slowing of the progression of Seiridium and Bot Canker: management, not control, is the ultimate goal.
Thinking long-term, plan to replace Leyland Cypress trees with something else, perhaps even a diverse selection of evergreens. A possible exception to this may be that situation described above where one plant would satisfy the screening needs for a particular view. A single plant located in such a situation may receive the light, air movement, and isolation needed to provide a healthy growing situation, provided the other needs outlined above are met as well. Avoiding the past history of cultural mistakes with Leyland Cypress and other conifers may help you avoid the heartbreak that has become so commonly associated with this tree. Refer to the links below for additional information:
Descriptions of the above photos, starting with the top row and moving left to right:
- Brown die-back in the branches shows the beginning of the development of disease in these Leyland Cypress trees.
- Even though the lower limbs of these trees may be thinning form shade-out and disease, the upper portions of the trees still provide privacy for this second-story deck. Plant Health Care to slow the advance of the disease may be a worthwhile investment in such situations.
- Amber-colored sap oozing from the branches and trunks is indicative of Seiridium Canker.
- These Leyland Cypress trees have Cercospora – another disease of Leyland Cypress.
- A close look at this Italian Cypress tree shows the same type of die-back, likely Seiridium.
- An example of advanced decline in a stand of Leyland Cypress.
The dwarf Hinoki cypress (Chamaecyparis obtusa ‘Nana Gracilis’) is a very nice plant indeed. It will grow well in USDA plant zones 5-8. You stated that you live in Zone 6 so that’s just fine. They like to be placed in full sun, need well drained soil and should be kept moderately moist.
In summer they need a good supply of water. If yours was kept in a pot over the summer months it’s possible it dried out, especially if not watered profusely. On the other hand the roots may have become soggy from over watering and poor drainage.
Now it is natural for the foliage at the centre of conifers to turn brown and drop over time. If plenty of green growth is seen at the tips the plant is probably fine. The amount of browning can vary depending on how stressful the growing season has been. Too much or too little water or light can turn the plant brown, as can poor drainage and root rot. Another thing to consider is lack of iron or other nutrients in the soil.
The best course of action right now is to wait and see how it responds next spring. Having moved it from a pot into a spot in your garden could have been stressful. Hopefully you watered the plant deeply when moved and its planted in a spot with good drainage. If you dislike the brown and there’s not too much you can pinch it out.
It might be a good idea to winterize your plant by wrapping with burlap. Cold temperatures and drying winds could also drain moisture from your Hinoki cypress.
Keep debris away from the soil beneath the plant to eliminate insects or fungal spores.
- Hinoki Cypress Troubles
- Italian cypress trees in North Texas are dying, and yep, it’s probably the weather
- Sustained assault
- Not much you can do
- Reasons Why Your Evergreen is Dying from Bottom Up – And How to Save
- Why is My Evergreen Tree Turning Brown from the Bottom Up?
Hinoki Cypress Troubles
For years these favorite slow growing trees had given me no trouble, Â only delight. That changed in the aftermath of one of the worst winters in memory.
I am not sure of the exact what or why, yet; but my oldest Chamaecyparis obtusa died from halfway up. Today, I finally removed that dead portion. I had been waiting for some dry days in which to do the job of cutting off the top of my most valued dwarf evergreen, because I suspect that it is a fungal infection that has taken its toll. If I don’t remove the dead portion, I think there will be no chance to save the tree.
Previously, there had been two Japanese cut-leaf maples nearby, both of which died mysteriously. They look healthy, although one had a large branch that had wilted and died. I had delayed removing it, and I think this is what may have given problems a foothold in my garden.
But again, I am unsure.
How Did This Happen?
Dead foliage on the Hinoki Cypress
I am not sure how it all happened, actually, but I do know that all through the summer the shrub seemed to be healthy and normal. After returning from a prolonged family trip in September, I returned to find that upper part of the evergreen was a deathly gray color. Going out to inspect it, more than just the foliage had died, the twigs also were dried and without life.
I had only recently discovered my Japanese maples, which had leafed out and looked fine, had wilted and then completely died. They had exhibited the same symptoms. One I had removed, using a disinfectant for the tool, the other left standing. All these Japanese native plants are in the same protected part of my yard.
Last years brutal winter, I believe, had weakened them, but I am unsure how the disease was introduced.
What I do know is that my most valuable dwarf trees are either gone or highly vulnerable to loss.
Using the symptoms as a search term I came up with a few educated guesses to the problem and the probable solution.
Juniper Tip Blight of some kind. The blights that hit Junipers also hit Hinoki cypresses, so this articleÂ on Phomopsis and Kabatina shed some light on the situation.
Whatever it is, it acts like a blight. Removing the dead and diseased part of the plant down to living parts seemed to be the only answer and my dwarf evergreen, the pride of my front garden, is now terribly deformed. I only hope it lives through the coming year. At that point I will see if I can help it to recover its form.
This has been a bad year of losses for my garden. I am trying to parse out what the contributing problems have been. Using mulch that may have harbored disease? The terrible winter we had? Introduction of unhealthy plants?
I will need to solve this conundrum, but at any rate, wherever the problem arose, no more of the vulnerable plants can be replanted in these areas.
I can no longer say thatÂ Chamaecyparis obtusaÂ is without problems.
Italian cypress trees in North Texas are dying, and yep, it’s probably the weather
Stressed Italian cypress trees throughout North Texas are turning an ugly brown, and many are dying. The problem has gotten so bad that trees in nurseries have been affected, so buy carefully.
The cypresses, often used to frame an entryway, have been hit hard by a combination of environmental factors. First, there was a long-term drought followed by record rains and then a sharp cold snap this past winter, says Micah Pace, an arborist with Preservation Tree Services.
Stressed by these conditions, the trees are falling prey to several diseases and pests, which cause large brown patches that often kill the tree.
“Multiple stress factors are affecting them all the time,” Pace says.
Kevin Ong, Texas A&M AgriLife Extension Service plant pathologist and director of the Texas Plant Disease Diagnostic Laboratory in College Station, suspects fungal diseases, root rot and spider mites are possible culprits.
Cypress trees can’t handle the extreme weather patterns in North Texas.(Micah Pace / Preservation Tree Services)
The trees, known as Leyland cypress, are not native to Texas and grow best in a Mediterranean climate. The Dallas area can be too cold for them, Pace says. While the area had a relatively mild winter, there was one particular cold snap that harmed the trees.
Add in the sustained drought that began in 2010, then record rains in 2015 and 2016, and the trees just can’t stand the sustained assault.
“We saw it coming,” Pace says.
Seiridium canker disease causes dieback on cypress trees.(Micah Pace / Preservation Tree Services)
Not much you can do
Some of the trees may survive, but that doesn’t mean they will thrive, he says.
There are no chemicals that will help. The best thing to do is call a professional, Pace says. An arborist can best advise whether the tree is likely to survive. Because of North Texas conditions, it may not thrive or look its best.
For those who want to save their trees, begin by clearing out dead foliage and other debris beneath the tree.
Then, cut out the brown limbs, dipping the pruning equipment in bleach between each cut to sterilize it, according to Ong.
Removing the tree may be best option, Pace says. Especially if the canker occurs on the trunk.
“This is just not an appropriate species” for our area, Pace says.
Karel Holloway is a Terrell freelance writer.
By Leonard Cicerello UCCE Master Gardener
Why are my Cypress dying in my front yard? Joe B. Paso Robles
A study published in 2011 by UC Berkeley and Italian researchers may have solved a decades-long mystery behind the source of a tree-killing fungus that affected six of the world’s seven continents. The pathogen, Seiridium cardinale, also known as Cypress Disease or Cypress Canker, was likely introduced from California either in the south of France or in central Italy 60 to 80 years ago. Its introduction devastated the region’s iconic Italian cypress trees. Researchers found historical catalogues of large commercial nurseries in Italy and France and found records of mature Monterey cypress trees for sale during the late 1920s and 1930s. The records indicated significant imports of the California trees and their seeds during that time.
Seiridium cardinale was first identified in California’s San Joaquin Valley in 1928. The fungus attacks trees in the cypress family by entering through cracks in their bark and producing toxins that wreak havoc with the flow of sap, limiting the supply of water and nutrients. The cracks in the bark could be caused by pruning cuts, boring insects, or weather damage. The spores spread by wind and water splash. Symptoms include dieback beginning from the top of the tree or branches browning and dying throughout the canopy. A branch can change color over a period of days.
You may see thin, elongated cankers on the stems and branches. These cankers cause twig and branch dieback. Most cankers are wounds, slightly sunken, with raised margins, and they may be discolored, dark brown to purple. An infected tree with cracked bark often has extensive resin that flows down the diseased branches and trunk. Once most of the canopy has turned brown, that limb or tree will almost certainly die. The whole limb or tree should be removed and properly disposed of.
The principal hosts for cypress canker are Monterey cypress, Italian cypress, Leyland cypress, Lusitania cypress, and Arizona cypress. It is best not to replant new cypress immediately following the removal of diseased trees. No specific cure exists. The best you can do is supply adequate water, minimize soil compaction, apply a thin layer of mulch, and avoid wounding the tree.
Reasons Why Your Evergreen is Dying from Bottom Up – And How to Save
Think back to the early days of your treasured evergreen tree. With meticulous care, you watched the tree thrive–sprouting emerald-green needles from the bottom all the way to the tippy-top.
Years later, those older bottom branches become a target for disease and insects.
Evergreen trees turning brown from the bottom up are unsightly. Plus, you’re likely wondering if this means your pine or spruce is dying. Look for these symptoms to see how to save your declining tree.
Why is My Evergreen Tree Turning Brown from the Bottom Up?
1) Water, Please
In drought-like conditions, evergreens may have trouble getting enough water to all their needles. As a result, bottom needles die to help hydrate the rest of the tree.
This problem is easy to fix!
If the tree’s soil is dry to the touch, give it extra water through summer’s dry spells. Continue watering throughout the fall, and apply mulch to seal in moisture.
2) A Pest or Disease
Evergreens attract a few common pests and diseases. Most commonly, there’s the pine beetle that attacks trees from the inside out, and the cytospora canker disease that leaves bulges on branches while seeping sap from the trunk.
Look on your evergreen’s branches for small holes or sawdust, which points to an insect infestation. To spot a disease on a pine or spruce, look for anything from large cankers leaking white sap to needle death on inner branches.
If you see something odd or worrisome, have an expert take a look. He’ll help diagnose and determine the best course of action.
3) It’s Just Natural.
Evergreens naturally wean out older needles as part of their growing cycle. Plus, when higher needles branch out, lower ones blocked from sunlight may die off. Since trees have a finite amount of energy, they want to prioritize the needles that can get sunlight to complete photosynthesis.
As long as the soil is moist to the touch, and you don’t spot an infestation, your tree is in good shape.
Check in with your arborist to see if it’s safe to prune browning branches for a better appearance. Just to be safe! This way, if there is a problem, we can spot it and develop a treatment plan sooner.