Bradford pear trees (Pyrus calleryana 'Bradford') are susceptible to some problems, like weak branches during inclement weather. Another common issue can be brown leaves or yellow leaves during spring or summer, a time of year when it should have green foliage. You can expect Bradford pear tree leaves to turn color in fall, but not yellow or brown; this tree is known for its beautiful crimson red foliage in autumn.
Read on to learn the reasons for unseasonable brown or yellow leaves on Bradford pear trees, including when the tree was planted, watering or soil drainage issues, or a nutrient deficiency.
Bradford Pear Tree Leaves Turning Yellow in the Spring
If your Bradford pear tree has leaves that turn yellow or brown in spring or summer, something is going on. The leaves should be a lovely robust green.
When you see leaves turning yellow on a Bradford pear tree during the spring, rule out a nutrient deficiency. For example, an iron deficiency in the soil causes chlorosis in plants. Get your soil tested by sending a sample to your county extension office. The agents can interpret their findings and offer recommendations.
Yellowed leaves will have green veins if the chlorosis is not too severe. In more severe cases, the leaves will be entirely yellow and start to brown and die. If it's an iron deficiency, you can use an iron spray treatment on the foliage or iron treatment on the soil.
If it's not an iron deficiency, it can be a deficiency of other nutrients your tree needs. You can try applying a micronutrient fertilizer to the tree's soil at the drip line. A buildup of salts can also affect your tree's absorption of water and minerals. A soil test can rule that out.
Watering or Drainage Issues
Yellow leaves on Bradford pear trees in the spring could also be a sign of overwatering. Poor drainage is likely the underlying—and bigger—problem whether the plant receives too much rain or excessive manual watering. Water will pass relatively quickly through soil that drains well, and plants are less likely to be adversely affected by too much water.
If you have clay soil retaining water, you may need to improve the drainage or aerate the soil. If the specimen sits in a low spot, you may also need to improve the drainage of the surrounding ground. Aerating clay soil usually involves puncturing the ground with an auger. Improving drainage can be done by digging channels to facilitate runoff; however, this is more feasible in a mulched area than in a lawn area.
As a general guideline, a Bradford pear tree should be watered twice a week during spring. It might be best not to supply supplemental water if it rains a lot.
Fire blight is a bacterial disease that affects fruit trees. The leaves brown, then blacken and appear as if affected by fire damage. It first occurs in the spring during rainy, humid conditions when the temperatures are over 60 F.
All parts of the tree can get it, and it can get passed by splashing water and insects. The best prevention is planting disease-resistant varieties of Bradford pear trees, sanitizing pruning shears during plant work, and using bacteriacide when necessary. Prune away affected branches immediately to stop the bacteria from spreading. If it affects the entire tree, it will kill it.
Another disease, pear scab, is caused by a similar fungus in the Venturia genus that causes apple scab. It can infect leaves, fruit, and young twigs. The disease's first sign is olive green, dark brown, or black soft circular spots or lesions on leaves. Like fire blight, it crops up in similar climate conditions—rainy, humid, warm spring days. The disease spreads through splashed moisture, so remove and destroy all affected foliage, and water your tree in the morning when excess water will dry the fastest.
Bradford Pear Tree Leaves Turning Brown in the Summer
A healthy tree can often fight off a myriad of attacks. Control environmental factors as best you can to reduce stress for your Bradford pear tree. Lack of water, a failing root system, or an insect infestation can mean life or death for your tree.
Correct Planting Time
Leaves turning brown is a common problem with Bradford pear trees planted in the summer. It's natural to assume that the problem is related to watering. However, the biggest problem is not how much or how little water your Bradford pear tree may be getting but rather the time of year you decided to plant it. Summer isn't the best time to plant trees. Generally speaking, spring and fall are the best times.
In this case, Bradford pear trees are slow to establish roots. The summer heat is difficult for new trees to tolerate under the best circumstances, which is doubly true for plants that are slow to root. Providing cover for the tree with a shade cloth or some other shelter can help protect the tree from the blistering sun.
A Bradford pear tree planted in summer is under stress, and the brown leaves may be due to leaf scorch. Watering requirements for young Bradford pear trees depend on several variables, particularly soil type.
Watering recommendations for different soil types:
- One inch of water per week for well-draining soil.
- Two inches of water per week for sandy soil.
- Less than one inch per week for clay soil that retains water well.
A tiny flying insect, pear psyllas, can also cause leaf yellowing and drop. Nymphs and adult forms of this bug inject the leaves with yellowing toxins. They can also introduce disease (Pear decline phytoplasma) through saliva and sooty mold problems due to excretions.
Heavy infestations will stunt growth and fruiting. If your tree is already showing extensive damage due to the pear psylla, it may not be possible to revive it. To prevent pear psyllas from visiting your tree, spray petroleum oil on the leaves in late winter to deter egg laying.
What If the Neighboring Trees Are Fine?
Problems based on soil conditions (nutrient deficiencies, drainage problems, etc.) can be highly localized. Soil conditions can change in just a few feet. Likewise, not all plants are created equal or have had the same start. For example, one plant may develop chlorosis in the same soil where another plant grows without problems.
According to the University of Arizona Extension, "susceptibility to iron deficiency varies greatly between plants, and it is not uncommon to see a plant with severe iron deficiency growing adjacent to one in identical soil with no symptoms at all." Never take it for granted that two trees of the same type growing right next to each other will fare the same.
Chlorois. University of Wisconsin Extension Service.
Yellow leaves on Bradford pear tree. College of Agricultural, Consumer and Environmental Sciences of New Mexico State University.
Fire blight of fruit trees. Clemson Cooperative Extension.
Pear Scab in Oregon: Symptoms, disease cycle and management. Oregon State University Extension Service.
Pear psylla integrated pest management. Washington State University.
Insect pests of pear trees. Ohio State University.
Recognizing and Treating Iron Deficiency in the Home Yard. University of Arizona Cooperative Extension.