- Why ‘Bradford’ Callery Pear Tree Leaves Are Brown, Black or Falling Off
- What is ‘Bradford’ Callery pear fire blight?
- Why are my Bradford pear leaves turning brown?
- Problems With The Bradford Pear Tree – Cincinnati Tree Services
- Bradford pear under fire from bacterial disease
- Bradford pear tree may have heat damage
- GUIDE TO PEAR TREE PEST AND DISEASE
- YOUNG FRUITS FALL OFF, BASE OF FRUIT IS BLACK
- DISEASED AND SUNKEN AREAS OF BARK
- YELLOW / OLIVE AREAS ON LEAVES
- BLACKENED BLOSSOM AND NEW SHOOTS
- APHIDS – SMALL INSECTS ON LEAVES
- SMALL BLACK LEECHES / SLUGS ON LEAVES
- EMERGING PEAR LEAVES HAVE SMALL GREEN / PINK / RED BLISTERS
- HOLES IN FRUIT
- ORANGE SPOTS ON LEAVES – PEAR RUST
Why ‘Bradford’ Callery Pear Tree Leaves Are Brown, Black or Falling Off
Some trees really know how to make a statement–like the ‘Bradford’ Callery pear. With its gorgeous canopy full of delicate, snow-white flowers, it’s sure to catch your eye (or your nose) in spring.
Or perhaps something a bit less joyful drew you in. That’s what happened to Linda, a Davey blog reader from South Carolina.
Linda asked, “My Bradford pear trees have clumps of brown leaves all over it. What can you tell me?”
What went wrong with Linda’s trees? And, if your tree is showing similar symptoms, what can you do? Your Bradford pear is likely dealing with a common springtime fruit tree infection. Learn what you can do about it below.
What is ‘Bradford’ Callery pear fire blight?
The brown clumps on Linda’s trees point to an infection called fire blight.
Fire blight is a persistent disease that affects ‘Bradford’ Callery pear (and other ornamental pear trees). But it goes after other fruit trees as well like apple, crabapple, quince and hawthorn trees.
At first, this is mostly an aesthetic issue, but if it keeps happening year after year, it could kill your tree.
Why Ornamental Pear Tree Leaves Are Dying (Turning Brown, Black or Falling Off)
Fire blight emerges in spring just as temperatures warm up and seasonal rain trickles down.
It targets trees right as they begin to bloom, which noticeably damages new growth. As its name suggests, it can look like a fire has burned certain areas of your tree.
To see if your ornamental pear or fruit tree may be suffering from fire blight, look for:
- Leaves that are crisp black or brown and later fall off entirely
- Flowers that turn brown or black and begin to wither
- Twigs that turn maroon or black and curl over as if they’ve been burned
- Branches with sunken, cracked areas
- A whole tree that looks wilted, shriveled and sickly
How can you help your Bradford pear or fruit tree with fire blight?
- Patience. If you spot symptoms of fire blight in spring, sit tight. Trying to prune or pick out dead leaves right away could actually spread the bacteria.
- Time your treatment. It’s best to wait until late fall or winter to do this. But if you really want to get those branches sooner, try doing this during a summer dry spell when it’s over 85 degrees.
- Prune. Cut about 6 to 8 inches below the affected area to remove infected branches. Be sure to disinfect your pruning tool between cuts. Dip or spray it with 70-80% isopropyl rubbing alcohol to avoid spreading the disease to other branches.
- Avoid fertilizer. Fertilizing your tree can help fire blight spread and become more severe. So postpone any fertilization treatments until after you prune.
- Play the long game. If your tree keeps getting fire blight every year, be proactive! In spring right as the tree blooms, apply a spray containing a labeled bactericide. Re-apply every 3-5 days until the blooms are finished. This will hopefully reduce, but not eliminate, fire blight.
Why are my Bradford pear leaves turning brown?
Q. I have two Bradford pear trees in my backyard. About half the leaves on one have turned dark-burgundy-brown while the leaves on the other tree are a healthy green.
A: It could be fire blight. Symptoms of this bacterial disease: bent branch tips that resemble a shepherd’s crook and brown-black, wilted or curled leaves. Affected portions of the tree look “scorched.”
Weeks of rain have prompted tender new growth that’s more susceptible. Take damaged leaves to a certified nurseryman for a proper diagnosis.
Cultural and chemical treatments exist for fire blight, but chemical solutions are often not recommended for home gardeners. Tall trees are difficult to treat. The disease is unsightly but usually does not kill ornamental pears. Streptomycin sulfate, which is an antibiotic, a bordeaux mix or copper fungicide can be applied according to package instructions when the tree is in bloom.
You can prune affected branches, but avoid excessive pruning; it will encourage more succulent, susceptible growth. Disinfect clippers in a 10-percent bleach solution after each cut. Avoid nitrogen fertilizer, which encourages vigorous growth.
Problems With The Bradford Pear Tree – Cincinnati Tree Services
What Are The Issues With Bradford Pear Trees?
Bradford Pear trees were once admired by subdivision builders and homeowners for their beautiful spring flowers. The beautiful perfectly symmetrical shape has made them very attractive over the years. However, the Bradford Pear tree has now become a troublesome tree in the Cincinnati area, due to their weak structure, and ability to be broken in half by a mild breeze. They are also susceptible to damage by rain or snow. Bradford Pear trees have a lifespan of only 20 years, but weather conditions may cause them to die long before that time. Here are some of issues with the Bradford Pear:
-They smell really bad, and the odor has been compared to that of rotting fish.
-Fire Blight – This is a bacterial disease which shows up first as branch and tree cankers which are areas of dead bark that appear in the spring. The cankers will excrete a tan ooze which turns to a darker color when it is exposed to the air. This disease attacks open flowers turning them black and causing them to wilt. Pruning the infected areas is a job for professional tree expert in Cincinnati, such a Tree Images. If the pruning is not done properly, then the disease can spread to other areas of the tree. The pruning equipment must also be disinfected. Mild to warm temperatures promote the ideal conditions for this bacterial disease to grow. It is best to not fertilize the trees with nitrogen fertilizer or prune the tree during this kind of weather. Doing so will only encourage the growth of this bacteria.
-Entomosporium Leaf Spot – This is a fungal disease and it usually develops during the cool temperatures and wet weather. This disease will show up as small, bright red spots on the surfaces of the leaves. If the infection is small, then it will be an eyesore more than anything else. If the infection is severe, the result can be leaf drop and damage to the internal structure of the tree. A professional tree expert should evaluate the appropriate response to this disease.
-Excessive Watering – Avoid excessive watering because too much moisture can increase fungal growth.
-Bradford Pear Trees Can Reproduce – When newer Callery pear cultivars pollinate Bradford Pears trees, the trees will produce seeds which may grow into trees that will crowd out other trees.
-Extensive Root Structure – The root structure can absorb so much moisture that surrounding plant life may die. This is also a serious problem when removing the tree from the yard.
One of our Bradford Tree experts will be pleased to evaluate your Bradford Pear Tree and recommend any action that is appropriate.
Bradford pear under fire from bacterial disease
If you have a Bradford pear in your yard, you may have noticed it is adorned with dead leaves and brown and curled branch tips this year. The problem goes far beyond your own front yard though; across the state, Bradford pears look nothing like their normal state as an idyllic ornamental tree. While the symptoms may be obvious, the culprit itself is a microscopic bacteria that causes a disease called fire blight. This bacteria can infect many types of fruit and ornamental trees in the rose family, even killing species considered most susceptible.
Fire blight causes browning and curling of shoot tips on diseased trees. This year, the disease is widespread in Bradford pear. Image: S. Thompson, NCFS.
The warm and wet conditions this spring provided the perfect environment for the fire blight bacteria’s growth, leading to widespread disease. Things started off fine with the trees blooming beautifully as always, but soon after, the flowers and young shoots began to turn black. What was not visible was the fire blight bacteria infecting new growth through infected rain splash or insect vectors such as cicadas or honey bees. After entering the tree through the flowers or small wounds, the bacteria spreads rapidly, killing plant tissues and causing shoot tips to bend over like a shepherd’s hook. These dead, blackened leaves hang on the tree throughout the summer, giving it a scorched appearance, hence the name “fire blight”. Once the trunk of the tree is infected, it will carry the bacteria forever.
Bradford pear is considered less susceptible to fire blight than most pear varieties. The tree may become disfigured but typically will not die. New growth such as fruits, flowers and shoots are most vulnerable. To reduce disease, pruning, fertilization and irrigation should be avoided during the spring. Because the bacteria can spread from tree to tree on contaminated equipment, pruning tools should be sanitized with bleach or alcohol between pruning jobs.
If fire blight is known to occur in the area, there are bactericidal sprays that may help reduce new infections. These are applied to new blooms during the spring, but because applications are needed every three to four days and are challenging for larger trees, this option may be unreasonable or costly in most urban settings.
So, break out your pruning shears. Keep the tree trimmed regularly, a practice which will increase air circulation and reduce the conditions in which many diseases thrive. You’ll thank yourself later!
Bradford pear tree may have heat damage
Q: Our Bradford pear tree is 2 or 3 years old and all of the leaves have fallen off. The limbs look reddish brown. I think the tree is dying, but my husband thinks the extremely hot temperatures this summer are to blame and that it will recover. What do you think?
A: July’s heat was very oppressive and a good number of young trees of different kinds have prematurely dropped their leaves. Bare branches can sunburn, turning them dark brown or reddish. You can settle this with a simple scratch test. Use your thumbnail to scrape off a bit of bark near the tip of a branch. If there is green beneath, the tree is alive. If the tissue is brown, it’s dead. In that case, go back a few inches on the same stem and test again. This is not the time to prune off dead wood, but if the entire tree is done for, fall is an excellent time to replace it.
Q: I planted a Woodall oak 3 years ago. Each summer the leaves turn brown and fall off but then the tree puts on new ones right away. Any idea if it will continue to do this?
A: Young trees will sometimes drop leaves and then releaf, apparently for no reason. If the leaves are not eaten or spotted and the tree is otherwise growing well, it can usually be attributed to stress. That is, heat or drought or excess rain can cause the leaves to pop off and a healthy tree just grows new ones. There’s nothing to do about it at this point in the season and as the tree matures it will be less likely to repeat the performance. Fertilize the tree next spring and water it in dry seasons to produce a good crop of leaves that can (hopefully) last the season.
Q: Our property is always wet as it’s a low lying field and I wonder if cypress trees are good for shade in this situation? Where can I get some seedlings?
A: The stately bald cypress trees can certainly take that wet setting, but there are other native trees that can complement their strong upright form. Consider planting a grove including some with broader, more horizontal forms like black gum (Nyssa) and spring flowers such as silverbells (Halesia). For more suggestions, refer to this publication written by Dr. Bob Brzuszek: . Ask your favorite independent nursery for tree availability and/or ordering and contact the local NRCS office for information about their tree programs, too.
Send questions to Southern Style, The Clarion-Ledger, Box 40, Jackson MS 39205-0040 or [email protected] Neal advocates for gardening 24/7 at her website, www.gardenmama.com.
GUIDE TO PEAR TREE PEST AND DISEASE
Feel free to email us using the form at the end of this page or via our contact us page for advice on pear pests and diseases. Also, please see our question and answer section on pear tree problems at the end of this article. Your question may already have been answered there.
YOUNG FRUITS FALL OFF, BASE OF FRUIT IS BLACK
This is almost certainly Pear Midge damage. To confirm it cut open affected young fruit and you will find small, cream-coloured maggots inside (see above).
Pear Midge damage to fruit
This pest can affect single pear trees whereas other nearby trees are completely unaffected. Affected fruit initially appears to grow larger and “rounder” than other fruit. Read our dedicated article on identifying and treating Pear Tree Midge here.
DISEASED AND SUNKEN AREAS OF BARK
If you can see a diseased area of bark on your tree then suspect canker especially if it is where a branch has previously been pruned. The bark will be split and slightly sunken at first – the sunken area will become larger as the disease progresses. The disease attacks the fleshy wood beneath the bark first so if you peel off a small bit of bark and see brown diseased wood below then your tree has canker. Canker often appears as ring-shaped cracks in the bark. for full information on identifying, treating and preventing canker on pear trees.
YELLOW / OLIVE AREAS ON LEAVES
Scab not only affects the leaves of pear trees it also affects the fruit. As well as yellow and dark green / black spots on the underside and top of leaves you may also see groups of the spores growing as small brown velvety mounds on the underside of leaves. Go to our dedicated scab page for treatment and prevention methods.
Leaf affected by Scab
BLACKENED BLOSSOM AND NEW SHOOTS
The symptoms of fireblight are hard to miss even at the initial stages of infection. First the blossoms are infected then new shoots, fruit and finally the main branches can be affected. The key symptoms are ….. for lots more expert information on identifying and treating fire blight on pear trees.
APHIDS – SMALL INSECTS ON LEAVES
The above picture shows aphids on a blackcurrant leaf but they look exactly the same on a pear tree leaf. Aphids first attack the undersides of leaves and this causes them to curl inwards on themselves. If left untreated the leaves will turn brown at the edges. Read our article on aphids here for expert advice on treating aphids both with chemical sprays and organically.
SMALL BLACK LEECHES / SLUGS ON LEAVES
This is the Pear Slug Sawfly (Caliroa cerasi). It affects pear, cherry and apple trees as well as some ornamental shrubs, hawthorns in particular. On fruit trees, the black leech like creatures are in fact green but covered with black slime. The slime is a protection mechanism to avoid being eaten by birds.
Pear Slug Sawfly (click to enlarge)
The lifecycle of the Pear Slug Sawfly starts with the pupae overwintering in the soil beneath the tree. In spring the actual sawflies emerge and lay eggs on the leaves. The eggs then hatch into the leech like creatures.
It is this slug / leech like stage which does the damage. They feed on the upper surfaces of the leaves with their black slime making them very unattractive to birds. The picture above shows the leaf damage very clearly, it is almost always restricted to the top surface of the leaf.
The larvae feed for three to four weeks and then fall off onto the ground. They will then hatch into a second generation within the same year and it is this second generation which does the significant damage. This normally occurs in late August to mid September.
In severe cases they can damage a huge amount of leaves. They are rarely fatal to the tree and fruit production is normally unaffected because the damage occurs so late in the year. They do make the leaves very unsightly however and can cause problems for already weak trees.
Removing them by hand and disposing of them is one solution but the size of many fruit trees makes this a difficult task. They can be knocked off with a strong jet of water. Spraying with a contact insecticide such as Bifenthrin was the most common treatment but in the UK this insecticide is no longer permitted for amateur gardeners.
Scotts Bug Clear is the recommended alternative but there is little hard evidence for how effective it is with the Pear Slug Sawfly.
EMERGING PEAR LEAVES HAVE SMALL GREEN / PINK / RED BLISTERS
When the leaves start to form in spring they have tiny, slightly raised blisters on them which are normally a pink / green colour. As the leaves develop the blisters deepen in colour to dark red turning to black or deep brown. Some leaves may be totally unaffected but this is very variable. These leaf marks are caused by Pear Leaf Blister Mites.
Picture from Ontario Crop IPM
The picture above shows the early stages of the mite infection. The marks will eventually turn to dark red / brown / black (see picture below). In advanced cases of this disease the fruit can also become deformed although this is unusual. Although the leaves can appear to be very damaged, fruit production is not significantly affected.
Later stages of Pear Leaf Blister Mite
HOW TO TREAT PEAR LEAF BLISTER MITES
Once you notice damaged leaves it’s impossible kill the existing midges which because they are protected by the surface of the affected leaves. Treatment consists of limiting the damage in the current year and spraying in winter to prevent damage the next year. We recommend the following course of action:
- Prompt action is essential to reduce damage in the current year. Pick off as many damaged leaves as possible to reduce the number of new mites – this pest has several lifecycles within a season. If the damage has been left until until the majority of leaves are affected then skip this step and continue to the next. Stripping off all the leaves will do more damage than good.
- The weak point in the lifecycle (see below) of this mite is during the winter when the adults hibernate either very near the surface of buds or in the joints between bud and stem. Spraying with a winter tree wash (available online and at garden centres) in November / December may well kill most of the mites.
- The Pear Leaf Blister Mites are far more active on trees which are under stress. Lack of water is often at the root of the problem so water well in dry conditions. Apply a long-lasting fertiliser such as blood, fish and bone in March.
LIFE CYCLE OF PEAR LEAF BLISTER MITES
The diagram below is a graphical representation of the life cycle of the Pear Tree Blister Mite
The following is a step by step description of the Pear Leaf Blister Mite life cycle. This pest has two or more generations of adults each year depending on weather conditions:
- Overwinter adults begin to burrow into developing leaf buds in spring when the weather warms up. They are roughly 0.20mm long and invisible to the naked eye.
- Each adult lays about 15 eggs which feed on the leaf tissue. This causes a blister to form which effectively protects from any chemical sprays.
- The centre of the blister breaks allowing mites in and out but in truth they move very little, they just feed!
- Normally there are three or so generations every year. The assumption is, although there is no proof, that the mites are spread from tree to tree by insects or birds.
- When the weather cools in September the adults seek out buds which will develop the next year. They overwinter at the base of the buds or just inside the first layer.
HOLES IN FRUIT
This section is courtesy of George Tondryk who spent hours examining video footage to determine the cause of holes in his pears. See the picture below for an example of the damage.
George sent me the relevant section of his video and it shows Blue Tits flying onto the fruits and pecking holes in them. Once the damage is done the holes may well have been enlarged by wasps and other insects but it’s clear from the video that the Blur Tits caused the initial damage.
With bird damage there are only two solutions, either net the fruit or grow them in fruit cages. Nothing else that I am aware of will work.
ORANGE SPOTS ON LEAVES – PEAR RUST
Where you see orange marks on the upper surface of the leaves combined with blisters and small growths on the lower surface this is a sure sign of Pear Rust. Less frequently it can cause smaller orange marks on the fruits. The Latin technical name for this fungal infection is Gymnosporangium sabinae.
Pear Rust on leaf top
The picture above shows the upper side of a leaf infected with Pear Rust. If you turn the leaf over you will also see the blistering which looks almost like little caterpillar legs with black dots in the centre – see picture below.
Pear Rust on leaf underside
The first point to note about pear rust is that there are no longer any chemical sprays available to UK gardeners to combat it. The two chemicals which were previously available have now been withdrawn. There are no pear tree varieties which are resistant to this infection
The life cycle of pear rust can hold a cure to its control. In autumn, as the leaves of pear trees are dying, spores are released from the rust infection into the air. If they are to survive winter they must find another plant which retains its leaves over winter. The rust spores in the UK have developed so that they are able to survive on juniper trees and bushes.
Severe case of Pear Rust
When the spores land on the juniper leaves they over-winter and spores are then again released in May / June time which blow onto pear trees and re-infect them.
One sure fire way to stop the infection spreading, and effectively kill it off, is to remove all juniper trees within a certain radius of the pear trees – half a mile should be more than sufficient. This is often not possible because the juniper bushes are growing on neighbour’s land.
Other than the above there is no method currently available to eradicate pear rust. The only alternatives are to reduce the level of infection and / or keep the pear trees healthy enough to withstand the leaf damage.
Where the infection is noticed early in the year, remove any leaves showing signs of damage which will help reduce the spread of the spores. If the tree is badly infected it’s best to leave the tree to its own devices. Removing large numbers of leaves will weaken it significantly.
General care of your pear tree as explained here will help it survive an attack. Occasionally, where the attack is severe, damage will also occur to branches and will cause cankers. These can allow the spores to overwinter on the pear tree without the need for juniper trees. These cankers should be cut out as described here.
Sometimes our readers ask specific questions which are not covered in the main article above. Our
Pear tree pest and disease comment / question and answer page
lists their comments, questions and answers. At the end of that page there is also a form for you to submit any new question or comment you have.