As summer inches along, there are a few things you’ve come to expect from your landscape: The grass isn’t growing so fast anymore. On the other hand, your petunias are. And all those perennials cut back late last year have come into their own again.
But now there’s something you’ve noticed that you weren’t expecting: Your tree leaves turning yellow. And then you’re flooded with questions… What’s causing the leaves to turn yellow? Was it planted wrong? Does it have a disease? Will it spread to my other trees? Is it dying? And so on and so forth.
Summer is the season when trees should be at their lush, green peak So when those green leaves start turning yellow prematurely, it can be alarming As a tree owner, yellowing summer leaves likely have you worried. Read on to find out the possible causes and solutions for this vexing issue.
What Causes Summer Leaf Yellowing?
There are several potential culprits behind summer leaf yellowing:
Improper Watering
Too much or too little water can cause leaves to turn yellow and fall off. Overwatering leaches nutrients from the soil, while underwatering starves roots of moisture. Check soil moisture before deciding whether to water more or less. Apply water at the tree’s drip line, not against the trunk.
Nutrient Deficiency
Lack of nitrogen iron, magnesium and other nutrients leads to overall yellowing known as chlorosis. Do a soil test to identify deficiencies. Amend soil per test recommendations. Fertilize regularly to maintain nutrients.
Pests
Insects like caterpillars, aphids, and spider mites damage leaves and drink sap. Animal pests like gophers munch on roots. Loss of leaf tissue and roots stresses the tree, disrupting water and nutrient transport. Inspect carefully for evidence of pests. Consult an arborist for identification and eco-friendly treatment.
Diseases
Fungal and bacterial diseases also disrupt the tree’s vascular system Powdery mildew and verticillium wilt are two examples Affected leaves turn yellow and wilt, An arborist can diagnose disease and recommend organic remedies,
Light Deficiency
Insufficient sunlight prevents leaves from photosynthesizing fully, causing yellowing. Plant sun-loving trees in full sun and shade trees in part shade for greenest leaves. If an established tree lacks light, prune or remove nearby trees. Or transplant the affected tree to a better spot.
Environmental Stressors
Heat, drought, and herbicide drift all cause leaf yellowing and drop. Monitor for signs of heat stress like wilting and scorch. Water deeply during drought if allowed. Avoid applying herbicides near vulnerable trees.
Genetics
Some trees like birch and tulip poplar naturally drop older or interior leaves in summer while maintaining the younger, exterior foliage. As long as the overall canopy appears full, this signifies normal leaf transition.
When to Worry About Yellow Leaves
- New leaves that emerge yellow instead of green
- Established green leaves turning yellow
- Excessive leaf drop
- Leaf wilting or drooping
These symptoms in summer likely indicate an underlying problem requiring attention. Don’t ignore extensive yellowing!
What to Do About Summer Leaf Yellowing
First, identify the cause. If it’s not obvious, consult an arborist. They can diagnose issues like pests, diseases, and nutrient deficiencies. Proper treatment depends on an accurate diagnosis.
Here are some general tips for helping yellow-leaved trees:
- Check and adjust soil moisture
- Mulch to cool roots and conserve moisture
- Fertilize to replenish nutrients
- Prune or remove competitive trees to allow more light
- Monitor for pests and diseases
- Plant trees suitable for sunlight and climate conditions
Prevention is also key. Proper site selection, watering, mulching, and pruning when trees are young helps avoid yellow leaf problems later on.
Don’t let summer leaf yellowing detract from your landscape’s beauty. A bit of tree care know-how keeps your trees greener when temperatures rise. Reach out to an arborist for help ensuring your trees thrive in the heat. With the right solutions, you can keep your canopy colorful and healthy all summer long.
Summary of Why Tree Leaves Turn Yellow in Summer
- Improper irrigation
- Lack of soil nutrients
- Pest and disease damage
- Insufficient sunlight
- Environmental stresses like heat and drought
- Normal leaf aging in some species
What to Do
- Check and adjust soil moisture
- Test soil and amend as needed
- Look for signs of pests and diseases
- Prune/remove trees for more light access
- Mulch and water during heat and drought
- Seek diagnosis and treatment from an arborist
Proper site selection and tree care helps avoid yellow leaves. But when they happen, accurate diagnosis and correction of underlying issues can return trees to green glory.
What is Chlorosis in Trees?
When leaves do turn yellow, this is a condition called chlorosis, which is an abnormal yellowing of the leaf tissue due to the loss of chlorophyll. Chlorophyll is a critical component to photosynthesis during the growing season because it allows a plant to absorb energy from light.
Tree Leaves Turning Yellow This Summer? It May Be Chlorosis
First things first: It’s important to understand that all tree leaves typically get lighter in color the further we get into summer. There are, however, a few more serious causes of leaf yellowing if your tree(s) is not provided optimal growing conditions.
River Birch Leaves Turning Yellow : Dropping Off In Summer
FAQ
How do I fix yellow leaves on my tree?
Watering Issues
If trees aren’t hydrated, the leaves can turn yellow as they try to conserve water. Test your tree’s moisture by using the screwdriver test. Stick a screwdriver into the soil. If it’s hard to push in, chances are the tree is thirsty and could use a deep watering.
Why are tree leaves turning yellow in summer?
Fertilizer Deficiency – Iron chlorosis — a lack of available iron — is one of the most common causes of yellowing tree leaves.
What is the best fertilizer for yellowing leaves?
Apply a liquid fertilizer containing iron or Liquid Iron, though it may leave a rusty residue on the leaves. This is only a temporary solution. Adjusting the soil pH is another option. Applying sulfur will lower the pH, allowing the iron to be more available to the root system.
Do yellow leaves on a tree mean too much water?
Poor Drainage or Improper Watering
Water issues — either too much or too little — are the leading reason behind yellow leaves.
Why do trees turn yellow in summer?
There are several potential causes related to site, care, weather, pests and disease that can turn tree leaves yellow in summer. Both over- and under-watering cause leaves to turn yellow and drop. Trees need a constant supply of moisture without soaked soils. Insufficient water will cause drought stress, while excessive water limits root oxygen.
Why are my trees turning yellow in Connecticut?
Below are some common reasons why trees in Connecticut may develop yellow leaves in summer or drop leaves early. Yellowing leaves, browning leaves, and leaf drop are all signs of water stress. This can be due to too much water or too little.
What does summer leaf yellowing mean?
Summer leaf yellowing gives clues that a tree is enduring stress whether from growing conditions, pests, disease or its own anatomy. Some amount of yellowing is expected, but extensive color changes or leaf drop indicate a tree isn’t getting what it needs to thrive.
What causes yellow leaves on a tree?
This loss of color is caused by a deficiency in chlorophyll, which is an essential part of a tree’s nutrient-gathering process. While yellowing leaves can be a sign of several different conditions, in North Texas, yellow leaves on a tree that is usually green are most often a sign of iron deficiency (“iron chlorosis”).
Why do trees turn yellow if they die?
Dead or dying leaves can turn yellow, but quickly become dark grey or brown. If a tree’s leaves become pale green or yellow, and stay that way, something is preventing the tree from generating enough chlorophyll. Chlorophyll is a naturally-occurring chemical in most plants, and performs an important function in leaves.
Why are my green summer leaves turning yellow?
When healthy green summer leaves start turning yellow or dropping early, it’s understandable to be concerned. Leaf color changes and leaf drop are often associated with fall, so it’s alarming to see these happening in the summer months.