Bartlett Tree Experts: Tree Diseases FAQs

Tree diseases can cause superficial and deadly damage to your landscape plants. Get answers to common questions about tree diseases in this section.

Tree Diseases FAQs (93)

What should be done about tall evergreens that are infected with orange gelatinous globs?
I have four scrub oaks in my front lawn, and after a drought, their roots came to the surface and are now taking over the lawn. Cutting them back doesn’t help, and it’s hard to keep up. Is there a way to kill the surface roots without harming the trees?
A 75-80 year old ginkgo tree at my father’s insurance office had 4-5 large roots cut during trenching for underground utilities, some 6-7 inches in diameter. We haven’t noticed stress yet, but we’re concerned it may kill the tree. Is there anything we can do to help it, and do you think it will die?
Are black tar spots on maple leaves harmful to the maple tree?
Our 10-year-old tree with an 8" diameter has marks and a chewed area in the bark from our dog. Do I need to treat or wrap the trunk to protect it?
I’m removing two 40-foot maple trees to make way for a septic leach field. Will the removal of the trees and roots cause more standing water on the ground, especially since they won’t be there to absorb excess water? The trees are about 20 feet from the house.
I have two 5' emerald cedars, and one is turning brown from the inside out. I’ve moved it back into a pot with good drainage and soil. Is there anything else I can do to help it recover?
I have a 100+ foot redwood tree and planned to place a planter at its base, three blocks high with dirt going up to the trunk. My neighbor warned that this could kill the tree. Is that true?
What kind of injection or injections should I use for a live oak that's 200 to 300 years old?
When is the best time to treat scale on a maple tree?
If I plant a tree where a stump has been grinded out, does that raise the possibility of honey fungus killing off my newly planted tree?
I have six mature redwoods in my yard in northern California. Given their size, location near structures, and proximity to storm risks, do they need regular trimming to prevent damage to the trees or nearby structures?
I am ready to remove the tree suckers from my live oaks in the backyard. But I wanted to know how high up should I remove them off the tree and can all of them be removed?
I have a 20-year-old tree in my front yard with a large blackening branch, green flaky material covering many branches, and branches dying off annually. What could be the cause?
I’m looking for a fast-growing tree for shade that looks nice. I like the Tulip tree but heard it can be messy with dropped flowers and black sap. Do you have any other suggestions?
My two Autumn Blaze Maples are struggling: one has dense leaves at the top and bottom but sparse in the middle, and the other has few leaves at the top with several branches needing pruning. Are they salvageable?
I have a large maple tree with exposed surface roots in my small backyard. We want to install a patio and do landscaping, which will require grading and removing some dirt. Is it safe to cut some of the roots, or could it damage the tree?
At what time of year should healthy, mature Japanese Maples be pruned?
My Queen palm tree died. I had it removed recently and was wondering when can I replant
My 7' Paulownia tree, planted a year ago, has large leaves with holes and brown edges, and most have fallen off. After spraying with Specticide Immunox, I’m unsure if it helped. What could be the cause, and what can I do to fix it?
My 25-year-old, 40-foot-tall giant sequoia has lost about 80% of its thick, dark bark, exposing bright tan, fuzzy wood that appears to be dry rotting, but I see no insects. Can you diagnose this severe bark loss and suggest treatment options?
What should be done about a Yoshino Cherry with Shot Hole Disease?
A tenant nailed a bird feeder into our 30-year-old Norway maple with 2–5 nails. Should I remove the nails and treat the holes, or leave them alone? The tree is healthy, and I plan to have it pruned this fall.
My neighbor parks on our shared lawn within five feet of a mature tree, driving within three feet of its trunk. Could this damage the tree’s root structure and threaten its health?
Our 12-year-old apple, pear, and peach trees have poor yields due to a lack of spraying and proper pruning. Could you provide a cost estimate for these services?
We recently had our maple tree pruned. It now has spots all over the leaves. Can you tell me what is causing this and what treatment options there are?
Can slime flux or wetwood kill a tree?
My twin-trunk tree, about 60+ feet tall, is leaning toward the house. I removed a dead trunk two years ago, and the roots were damaged years ago. How can I gauge its health?
How badly can trees be damaged by a lawn mower?
Over the past few years my apple tree has stopped producing a good crop of apples. The few apples that are produced go brown and rotten on the trees.
How should fire blight in an ornamental pear tree be managed?
My 5-year-old clump birch tree is showing yellowing and dying leaves after branch trimming two weeks ago, while my neighbor's birch is fine. What could be causing this?
Can you please advise a safe distance to plant a willow tree from electric transformers and sewage lines?
We have a large oak with a wooden bench and 2 feet of soil around it. If we remove the bench and soil, will it harm the tree, or should we leave the soil in place?
Our Juniper hedge is 12' tall and 6' wide. Can it be cut down to 5' tall and still survive?
How do I take care of an hibiscus tree?
After a storm knocked down my large Bartlett tree last year, several saplings have sprouted from the trunk, with some now 10 feet tall. Should I prune all but the tallest and healthiest sapling to help it grow?
What is the best time to prune my two ~20-year-old Live Oak trees in the Clear Lake area? The trees have low-hanging branches, dense areas that need thinning, and hurricane damage at the top. They’ve thrived, but the density is making it hard to maintain grass underneath.
How do I save an old, borer-ridden Apricot tree?
We have an elm tree that is leaning, with a sizable mound behind it where the roots must be pushing up. Is there any way to straighten it back up?
A Colorado Blue Spruce is suffering from some type of blight. Can the problem be determined and treated during the winter?
Is it possible to graft spruce to the top of where my neighbor topped two spruce trees to help them grow taller? If not, should I cut them down and start over? Also, can a tall (20-30 foot) spruce tree be transplanted?
When and how should I prune my Hydrangea tree?
Have you been able to save a 50 yr old elderica pine tree from Mediterranean pine engraver infestation?
The leaves on my magnolia are starting to go yellow yet the surrounding trees look fine. What could cause this?
Are Hawthorn berries poisonous?
I planted six young trees in early March. Despite watering them regularly they have all started to wilt and the leaves are starting to turn yellow.
When is the best time to plant trees?
Is Arborbiotic injected into the root collar or trunk flare? I understand annual injections may not fully control fire blight in Callery 'Redspire' pears despite using Forti Phite plus calcium, and infected branches need pruning six inches back with sterilized tools. Is this correct?
I want to spray Neem oil on my large magnolia tree which has a large amount of scale. How do I recognize the crawlers when they hatch? Are you seeing the crawlers hatched in central NY now ? Reference says late August to September. Thank you, Sue 9-10-18
I grow my own fruit and vegetables and am concerned about food contamination from fertilizing my trees and shrubs. Should I be worried?
My neighbor’s tree is planted near the property line, with its roots running across my yard and damaging my lawn. If I dig up the roots on my property and the tree eventually dies, would I be responsible for cutting it down or replacing it?
One of our hemlocks has a neat ring of sawdust around its base, with a few visible ants nearby. Firewood stored close to it last summer may have been infested. If this is ants or termites, can it be treated, and how should we proceed?
My autumn flowering cherries have been looking worse each year, with leaves full of holes and dead twigs. Do you know what could be causing this, and is there a cure?
My 9-year-old Leyland cypress is turning rust-colored and dying, and I've been told cypresses often die at around 8 years old. I've also been advised to spray it with horticultural oil. Should I remove the tree, or is there a way to save it?
My 6-foot bougainvillea vines in Houston, Texas, were exposed to mild freezes (29–30°F) for several hours. How should I prune them for the best recovery?
I have a large live oak and a large limb fell off. It is late July. What is the proper way to take care of this to prevent oak wilt?
I have a pine tree near my house that’s now taller than the house. I enjoy the shade it provides, but I’m concerned about whether the roots are harming the foundation. Should I cut the tree down?
This is the first time we have planted a fig tree. It has about 13 figs on it and I wondered how do I know when to pick them? Also, what do I do to keep the tree from frost in winter?
I have a 6-7 inch Tulip Poplar tree that drops dead limbs every year, and I prune a few out. Is the tree dying? Should I water it, and would fertilizer help?
My Autumn Blaze maple, planted in 2006, has white silky pod-shaped things on the smaller branches. What are they, and do I need to treat the tree?
This is the first summer that my semi-dwarf peach tree has had fruit. They are the size of marbles and are on the ground. I was told that the birds are pulling them off. Is this possible?
A neighbor is asking us to remove about 20% of the crown of our white oak due to overhanging branches, and we’re concerned about oak wilt. How should we proceed with pruning to best protect the tree, and can we inoculate it before doing the work?
I have two trees that have mistletoe, one in my front yard and one in my back yard. Are these problematic to the rest of the trees in my yard?
The impact of the drought in Texas has affected a 35' maple tree in my front yard. It is slowly trying to leaf out, one here and one there. What can I do to save this outstanding shade tree?
Our large Oak tree appears healthy with a full canopy of leaves but is rotting from the inside out, compromising much of the lower trunk. Given its proximity to condominiums, we’re concerned about its stability. Can it be saved, reinforced, or stabilized to prevent potential damage?
My neighbors are removing their 36-year-old Bradford Pear trees due to concerns about tree failure, citing a 30-year life expectancy. Is it a mistake to keep mine, or can it safely remain?
Black walnut trees have naturally sprouted on my property, and I want to keep some. Should I trim the lower branches now or wait another year? Also, when is the best month to prune them in Wisconsin?
When limbs have been trimmed from a tree, do you have to paint the tree where the limb was taken from?
I recently bought an 8' spring serviceberry, and the leading branch broke about 6" from the top during transport. Is it considered topped, and should I cut the broken part off completely, even though it’s only halfway broken?
I recently had one trunk removed from my mature oak tree, leaving an 18" diameter stump. Should I treat the stump with fungicide or tar to protect the remaining trunk from fungus or disease?
Bartlett treated my Maple trees for Phytophthora Canker with a spray, but it rained less than two hours later and heavily the next day. Could the treatment have been washed away?
Bamboo! How can I get rid of it?
I planted peach trees this spring, and while they have new growth and small fruit, many leaves are turning yellow. Is this normal, or do I have a problem? Also, what’s the best fertilizer for fruit trees?
I purchased two redbud trees last summer and watered them regularly, but they only have small shoots at the bottom two feet. Will they have new growth at the top, or is there no sign of life there?
My weeping cherry and blueberries were eaten by a bug, despite spraying with Monterey insect spray. Where do these bugs come from, and how can I prevent them in the future? We’ve had blueberries for 40 years without bug issues.
I have a 15-foot Oxblood Japanese Maple, planted 4 years ago, that’s too close to the house. How much can I trim it without harming the tree?
My neighbor claims my Chinese elm trees release poison, and I suspect he’s poisoning them, as others have seen him in my yard. What should I do to protect the trees?
I have three Little Gem Magnolia trees, about 8-10 years old, along my driveway that have been losing most of their leaves since last summer. What can I do to save them?
Our large Sycamore and others in the neighborhood started to leaf, but a cold snap seems to have killed the buds. Now, there are only sparse leaves on the tree. Will it recover, or is it doomed?
Do you have a solution to prevent fruit growth on a tree? I just want leaves, no blossoms or fruit, as the birds and animals are making a mess on my car, sidewalk, windows, and street.
There is a naturally occurring hole in our mature pecan tree. The hole is roughly 18 inches long and nine inches wide. Does this hole likely make the tree susceptible to falling?
We have a 25-foot Holly tree that’s lost a huge number of leaves, resulting in bare spots. Despite a healthy berry crop this winter, the tree is now see-through. Can anything be done to restore it, as it’s an important privacy tree for us?
Can I cut the top of a small two-foot fir tree to make it fill out?
I transplanted 25 fir trees, 6-7 feet tall, and want advice on winter care. Should I mulch, fertilize, or do anything else to protect them? They seem healthy, with no wilting or yellowing, and I’ve been watering twice a week.
My ornamental pear tree has lost leaves at the ends of branches across the entire tree. Should I prune the dead ends, and is there anything else I can do to help the tree?
I'm looking to plant trees about three feet from the sidewalk in a small garden, with a maximum height of 10–15 feet. I'm concerned about the roots damaging the sidewalk. Can you recommend tree options with manageable root systems for this space?
A workman accidentally got some black primer on the top of our mature green maple bush. Will the paint harm the bush? Can I trim the painted area, and should I wait until winter when the leaves drop off?
Is it damaging to trees to prune while temperatures are below freezing?
My 15-20 ft arborvitae, used as a natural barrier, were bent by winter snowfall. Can they be cabled together to realign, or will they straighten naturally if left alone?
I transplanted a 5-inch trunk boxwood in February, placed it in a box with oil dry, and water it daily. However, 70% of the foliage is gone, and remaining leaves are browning. Should I build a plastic tent, adjust the substrate, or take other steps to save it?
My 25+ year old fruitless mulberry is healthy but nearing the typical lifespan, and I’d like to establish another tree to maintain shade. Can I underplant a young oak beneath the mulberry to prepare for its eventual decline?
We planted a tree in the fall, following the grower’s instructions, but several lower branches are browning. Could poor drainage from a wet winter and spring be the issue, and what can we do to help the tree recover?