How To Stop Your Boxwood From Yellowing

You can stop your boxwood from yellowing by first figuring out what’s causing the discoloration.
 
The key to stopping boxwood yellowing is to treat the specific stressor affecting your shrubs.
 
Whether it’s water issues, pests, or nutrient problems, you can stop your boxwood from yellowing once you know the culprit.
 
In this post, we’ll walk through the most common reasons for boxwood yellowing and exactly how to stop your boxwood from yellowing for good.
 
Let’s dig in and get those leaves green again.
 

How to Stop Your Boxwood from Yellowing by Diagnosing the Root Cause

The fastest way to stop your boxwood from yellowing is to match the symptom with the cause.
 
Here are the main reasons for boxwood yellowing and how to address each one.
 

1. Overwatering or Poor Drainage

One of the most common reasons for yellowing boxwood is soggy roots.
 
When the soil stays wet too long, roots suffocate and the leaves turn yellow.
 
To stop your boxwood from yellowing due to overwatering, check the soil with your finger.
 
If it’s muddy or smells sour, you need to improve drainage.
 
Add compost or sand to heavy clay soil, or consider moving the boxwood to a raised bed.
 
Water only when the top inch of soil feels dry.
 

2. Underwatering and Drought Stress

On the flip side, too little water can also cause boxwood yellowing.
 
During hot, dry spells, boxwood leaves may turn pale yellow or brown at the edges.
 
To stop your boxwood from yellowing from drought, give it a deep soak once a week.
 
Mulch around the base with 2-3 inches of organic matter to hold moisture.
 
Just keep the mulch away from the trunk to prevent rot.
 

3. Nutrient Deficiencies

Yellowing boxwood often lacks key nutrients, especially nitrogen or iron.
 
To stop your boxwood from yellowing due to poor nutrition, apply a balanced, slow-release fertilizer in early spring.
 
A fertilizer formulated for evergreens works best.
 
If the yellowing shows up between the veins (called interveinal chlorosis), your boxwood likely needs iron.
 
Use an iron supplement or chelated iron spray to fix boxwood yellowing quickly.
 

How to Stop Your Boxwood from Yellowing by Correcting Pests and Diseases

Sometimes boxwood yellowing is a sign of an infestation or infection.
 
Here’s how to stop your boxwood from yellowing from these problems.
 

1. Boxwood Leafminer

This tiny pest tunnels inside the leaves, causing yellowing and blisters.
 
To stop your boxwood from yellowing from leafminers, prune out affected branches in late winter.
 
Apply horticultural oil or systemic insecticide in early spring when new growth appears.
 
Good sanitation also helps stop boxwood yellowing from returning.
 

2. Boxwood Blight

Boxwood blight causes dark spots on leaves that turn yellow and drop off.
 
To stop your boxwood from yellowing from blight, remove all infected foliage immediately.
 
Disinfect your pruning tools between cuts.
 
Apply a fungicide labeled for boxwood blight, following label directions.
 
Prevention is key, so avoid overhead watering and space plants for airflow.
 

3. Root Rot (Phytophthora)

When roots rot from fungal pathogens, the entire plant turns yellow.
 
To stop your boxwood from yellowing from root rot, improve drainage and remove affected plants.
 
You can try drenching the soil with a fungicide, but severe cases may require replanting.
 

How to Stop Your Boxwood from Yellowing with Proper Seasonal Care

Winter and early spring are common times for boxwood yellowing.
 
Here’s how to stop your boxwood from yellowing during cold weather.
 

1. Winter Burn

Cold winds and bright sun dry out leaves faster than roots can replace moisture.
 
The result is yellowing boxwood in late winter.
 
To stop your boxwood from yellowing from winter burn, wrap your shrubs with burlap or anti-desiccant spray in late fall.
 
Water well before the ground freezes.
 

2. Sun Scald

Newly planted boxwood in full sun may yellow from too much direct light.
 
To stop your boxwood from yellowing from sun stress, provide afternoon shade or use a shade cloth during heat waves.
 
Once the plant is established, it will tolerate more sun.
 

3. Improper Pruning

Cutting too much foliage at once can shock boxwood and cause yellowing.
 
To stop your boxwood from yellowing from pruning stress, only remove one-third of the plant per season.
 
Use sharp, clean shears to make clean cuts.
 

So, How to Stop Your Boxwood from Yellowing?

You can stop your boxwood from yellowing by addressing the specific cause of stress.
 
Whether it’s water, nutrients, pests, or weather, the solution starts with a good look at your plant.
 
Following the steps above will help you stop your boxwood from yellowing and keep it lush and green.
 
Remember to check regularly for early signs of boxwood yellowing so you can act fast.
 
With the right care, your boxwood will reward you with vibrant foliage for years to come.