- Why Are There Yellow Leaves on Trees in Summer?
- Caring for Your Birch Tree
Why Are There Yellow Leaves on Trees in Summer?
Rich, green leaves are a staple of summer. They’re crisp, bright and a pleasant addition to every landscape. Plus, we love their shady canopy on sunny days.
So if you spot yellowing leaves on your trees, you want them to return to their green glory. An Ontario-based reader recently had a similar goal. She asked us why her river birch leaves were turning yellow and falling off – and how she could fix it.
There are many reasons why you too could see these symptoms. Run down the checklist below to help diagnose your tree.
Test 1: Test for dry soil
If trees aren’t hydrated, the leaves can turn yellow as they try to conserve water.
Test your tree’s moisture by sticking a screwdriver into the soil. If it’s hard to push in, chances are the tree is thirsty and could use a deep watering.
Test 2: Check soil moisture
If the screwdriver test proves there’s moisture deep into the roots, water less.
Your reflex might be to water at the sight of suffering leaves, but overwatering can also lead to yellowing and leaf drop.
Test 3: Inspect and treat
Yellowing leaves and premature leaf drop may point to a leaf disease or summer pest infestation. Consider a free tree inspection to identify the pest or disease and the best treatment.
If an infestation is ruled out, the checkup may reveal a deficiency called chlorosis, which strips leaves of the chlorophyll needed to keep them green.
Begin by performing a soil test and adding any necessary soil amendments. Fertilizer also replenishes lacking nutrients, which in turn helps your tree. Remember, these actions need to happen on a regular basis to have a lasting impact.
Why, specifically, is my birch or river birch getting yellow leaves in summer?
If you, too, are seeing yellow leaves on your birch tree, there could be a couple reasons why.
Run through this checklist just for birch trees to find out what the problem is:
- Are there spots on those yellow birch leaves? If so, the problem is likely a leaf disease.
- Do you see something sticky on the bottom of the leaves? If so, it’s probably an insect.
- How much are you watering? As their name implies, river birches love to drink water. In the summer, when the water is limited, they’ll drop leaves if they get thirsty enough. To remedy, deeply water your birch tree each week, and add mulch to conserve moisture.
- How hot is it? If it gets too hot for too long, these trees drop leaves to conserve energy. This happens most often to newly planted trees. They toughen up a bit as they mature because their root system becomes better established.
- Didn’t see any of the above? Check the soil to see if there’s enough iron (or if the soil has too much pH). Remedy the problem with soil amendments or treatments.
Q: We have a birch tree in the front yard which I think has exceeded its water resources. I have to rake every other week to prevent the brown dry leaves that fall in that period from blowing into the neighbor’s yard.
I have a drip hose under the mulch that I now turn on twice a week until water starts running down the driveway (about 30 minutes – 1 hour watering).
Should I remove it?
A: River birches typically lose leaves in July due to heat and water stress. Yours looks pretty healthy to me. The tree would lose fewer leaves if you extended the mulched area out to the ends of the branches and put more soaker hose out there where the roots are.
The name “river birch” indicates the environment this tree loves: moist riverbanks. When the soil around its roots gets dry, the tree quickly shows its unhappiness by dropping leaves. I see plenty of healthy river birches in full sunshine but I also see many which respond like yours every summer. The good news is that early leaf drop never seems to hurt a birch permanently.
Right now, the bermudagrass is stealing most rainfall and the soaker hose is putting water at the base of the tree where there are few roots to absorb it.
I see no reason to remove the tree.
Tags For This Article: mulch, Summer
Caring for Your Birch Tree
The birch tree is popular among homeowners due to its beautiful bark, modest size and graceful branches. Two of the most common birch tree species in the Northeast are the River Birch and White Birch. The White Birch tree is characterized by its beautiful white bark (when mature) and drooping branches, whereas the River Birch tree has a brownish-red exfoliating bark and pyramidal to rounded crown. These characteristic bark qualities provide interest in the landscape throughout all four seasons. A birch tree’s leaves are green with sharp edges, which turn yellow in the fall depending on the species.
How to Grow Birch Trees: Due to its shallow root system the birch tree is very sensitive to heat and drought. It needs moist, cool soil, but also sunshine on its leaves to flourish. When planting a birch tree select a site that will shade its roots in the afternoon and still provide sun to canopy for much of the day. Mulching also helps to maintain soil temperature.
Most birch trees grow best in slightly acidic soils, although White Birch trees can grow in alkaline soil. Keep in mind the height of the full grown trees when planting and do not plant under overhead wires. These attractive ornamentals do require a little extra care to ensure a long life-span.
Size of a Birch Tree: 30-65’ high / 15-30 spread depending on species
If you’d like to establish birch trees in your landscape, we can connect you with one of our pre-vetted landscape experts that can help you select, purchase and plant new birch trees.
Birch Tree Care
Birch trees are susceptible to borers as well as other insects and tree diseases. A preventive insect control program is recommended to reduce problems. Keep your birch trees as healthy as possible through regular monitoring, pruning, watering and using birch tree fertilizer.
Newly planted birch trees benefit from ArborKelp®, SavATree’s exclusive seaweed biostimulant which aids in tree establishment, promotes root growth and heightens stress tolerance.
Mature and established trees benefit from fertilizer feedings of organic-based macro and micronutrients for the nutrition necessary to sustain their health.
Pruning Birch Tree Leaves
Birch trees should be trained to grow with a center leader and should be pruned to maintain optimal health and a strong structure; remove lower hanging branches that interfere with walkways or driveways.
Birch tree pruning is recommended to preserve or improve tree structure, vigor and life-span. Pruning can reduce specific defects or structural problems in a tree to greatly lessen the risk of failure.
Broken, diseased, or dead branches are typically removed in order to prevent decay-producing fungi from infecting other areas of the birch tree.
Removal of live branches is occasionally necessary to allow increased exposure to sunlight and circulation of air within the canopy of the birch tree. This assists in reduction of certain tree diseases. We also advocate the removal of branch stubs to promote successful and proper healing of wounds.
Your SavATree certified arborist is equipped with the latest techniques and state-of-the-art equipment to keep your birch trees healthy, beautiful and safe. Contact us today for information on birch tree pruning or any of our other birch tree care services.
Prevent Birch Tree Diseases & Pests
There are several damaging birch tree diseases and pests. Some of the most common are:
Bronze Birch Borer – This potentially lethal pest can be difficult to control in birch trees. It is an invasive wood-boring beetle whose larvae bore into the layers of the tree and interrupt the flow of sap. Trees that are weak and already have wounds in the bark are especially susceptible to attack. Indications of a problem with a bronze birch borer infestation include winding galleries just beneath the bark in the trunk and thinning at the top of the crown of the tree. Fortunately pruning and other treatments are available that can help protect your trees.
Birch Leafminer – The larvae of this insect burrow into the birch leaves looking for nutrients. To identify the problem look for small green spots on the leaf surface in May or June. The leaves will then develop brown splotches. While the birch leafminer usually does not kill the tree, it can disfigure and weaken it, making it more susceptible to a bronze birch borer infestation.
European Birch Aphid and the Common Birch Aphid – Aphids suck the sap out of the birch tree leaves causing them to yellow and twist. A severe infestation can cause leaf drop and branch dieback. Often the undersides of the leaves seem to be dripping with sap. This is honeydew secreted by the aphids, which in turn, attract ants.
Other birch tree diseases, problems and pests include:
- Birch canker
- Heart rots
Many of these insect and disease conditions can weaken the tree and lead to tree death if not treated. If you suspect a problem with your trees, call a SavATree certified arborist right away for an evaluation and treatment options. Our birch tree care experts can help protect your trees and keep your landscape beautiful.
Diseased photo: Birch disease 5393596-Bronze Birch Borer by Whitney Cranshaw, Colorado State University, Bugwood.org
This recent and long dry spell we’ve been in has me spending lots of time attending to the watering needs in my lawn and garden. The most noticeable effects of the lack of rain are with the birch trees in the area, including on my own property. All of my birch trees, which include river birch and white spire, are well established and are all at least 15 years old. But yellowing of leaves and dieback this time of year is something I am well aware can happen if the watering needs of these trees are not met throughout the season. Apparently, due to some situations beyond my control, those watering needs were lacking and several of my birch trees are covered with yellowing leaves that then turn brown and drop to the ground. Luckily, I’m not noticing any dieback on the branches and for at least the last two weeks, I’ve gone full speed ahead on properly watering each and every one.
Yellowing and leaf dieback along with dying branches on birches is commonly caused by insufficient watering but can also be caused by a lack of iron. Iron is a necessary micronutrient that birches need and sometimes, for a variety of reasons, the iron gets bound up in the soil and the tree’s roots are unable to absorb enough. This condition is called Iron Chlorosis. A soil test should be able to tell you if this is the problem you are having.
For the most part, though, the likely problem is drought either from lack of rain, not watering or improper watering. The obvious signs are foliage that wilts and turns brown or may turn a dull gray-green color. Dried brown to gray-green leaves hang on the tree or more commonly, foliage drops prematurely and litters the ground under the tree. Severe drought stress may cause dieback of individual branches starting at branch tips.
To properly water any tree, the water must reach the feeder roots that take in water and nutrients. Those roots are located at the drip line of the tree. The drip line is below the widest part of the tree canopy. That could be several feet from the trunk so watering the truck area isn’t at all efficient. Using a sprinkler that will easily reach the drip line is the best way to water a tree unless you are going to water that area by hand. You’ve watered enough when the soil is moist at least 6-8 inches below the soil surface.
For more information on growing birch trees, visit http://www.na.fs.fed.us/SPFO/pubs/howtos/ht_birch/ht_birch.htm.