Why Are My Yews Turning Brown

If you’re noticing unsightly brown patches on your evergreen yews, you’re likely searching for answers. This article will explain why are my yews turning brown and what you can do about it.

Yews are generally tough, but browning is a common distress signal. It can be caused by environmental stress, pests, disease, or simple care mistakes. The good news is that many causes are treatable once you identify the source.

Let’s look at the most frequent culprits behind browning yew foliage. Accurate diagnosis is the first step to a cure.

Environmental and Watering Stress

This is often the root of the problem. Yews have specific needs, and when those aren’t met, they react.

Drought Stress: Yews need consistent moisture, especially when young or in well-drained soil. Underwatering causes needles to turn a rusty brown, often starting at the tips and outer branches before moving inward.
Winter Burn (Desiccation): This is a major cause of browning in late winter/early spring. Frozen ground prevents roots from taking up water, while sun and wind pull moisture from the needles. The result is brown or bleached foliage, typically on the south or windward side.
Waterlogged Soil (Root Rot): The opposite problem is just as bad. Yews hate “wet feet.” Poorly drained soil suffocates roots, leading to root rot. The plant will show a general decline, with browning needles that may start near the trunk or on lower branches.
Salt Damage: Road salt spray or runoff can burn foliage, causing browning on the side facing the road or walkway. Salt in the soil also disrupts water uptake.

Pest Infestations

Certain insects specifically target yews. Their damage is often distinctive.

Black Vine Weevil: The adults notch leaf edges, but the real damage is done by their C-shaped, white grubs in the soil. These grubs feed on roots, causing sections of the plant to wilt and turn brown suddenly.
Mealybugs and Scale: These sap-sucking insects attach themselves to stems and needles. They weaken the plant, leading to yellowing then browning foliage. You may see cottony masses (mealybugs) or small, hard bumps (scale) on the branches.

Fungal and Disease Issues

Fungal pathogens thrive in wet conditions and can quickly damage your yews.

Phytophthora Root Rot: This is a serious soil-borne fungus in waterlogged conditions. It causes roots to decay, leading to a overall brown decline. Stems may have dark streaks under the bark near the soil line.
Needle Blight: Fungal diseases like Pestalotiopsis cause random browning or black spots on needles, often followed by dieback of whole branches. It’s more common on plants already stressed by other factors.

Cultural and Physical Damage

Sometimes, the cause is something we’ve done or overlooked.

Improper Pruning: Cutting yews back into old, brown wood (beyond the green needle growth) will result in permanent bare spots, as they rarely sprout new growth from old wood.
Nutrient Deficiency: While not super common, a severe lack of essential nutrients like nitrogen can cause overall yellowing and browning. Poor soil is usually a contributing factor here.
Animal Damage: Deer will browse on yew foliage, especially in winter, leaving ragged, broken brown ends. Voles can chew bark and roots at ground level, girdling and killing sections.

Step-by-Step Diagnosis Guide

Follow these steps to figure out what’s wrong with your yew.

Observe the Pattern: Is the browning on the tips, inner branches, outer branches, or one specific side? Winter burn is often one-sided; root issues cause more general browning.
Check the Soil: Dig a small hole 4-6 inches deep near the plant. Is it dust-dry or soggy wet? Both are problems.
Inspect the Foliage and Stems: Look closely for insects, cottony residue, or tiny holes. Check if brown needles pull off easily or if they’re still attached firmly.
Examine the Base and Roots: Gently scrape a little bark near the soil line. Healthy tissue is green underneath; diseased tissue is brown or black. Look for vole tunnels or chewed bark.
Review Recent History: Was there a dry spell, a very wet season, extreme cold, or nearby construction that could have damaged roots?

Solutions and Treatments

Once you’ve identified the likely cause, take these corrective actions.

For Environmental Stress

Watering Correctly: Provide about 1 inch of water per week during dry spells. Water deeply at the base, not on the foliage. A soaker hose is ideal. In late fall, water deeply before the ground freezes to prevent winter burn.
Improving Drainage: If soil is heavy clay, consider amending with compost or even transplanting the yew to a raised bed. Avoid planting in low spots where water collects.
Protecting from Salt: Rinse foliage in early spring if sprayed with salt. Use burlap screens as a barrier in winter. Plant salt-tolerant species near roads instead.
Applying Mulch: A 2-3 inch layer of wood chip mulch around the base (not touching the trunk) helps retain soil moisture, regulate temperature, and prevent weed competition.

For Pest Problems

Black Vine Weevil: For grubs, apply a beneficial nematode solution to the soil in late summer or early fall. For adult weevils, inspect at night with a flashlight and hand-pick them, or use a labeled insecticide if infestation is severe.
Sap-Sucking Insects: For light infestations of mealybugs or scale, scrub branches with a soft brush and insecticidal soap solution. For heavier cases, use horticultural oil in the dormant season to smother overwintering pests.

For Fungal Diseases

Root Rot Prevention: The best cure is prevention through good drainage. If root rot is suspected, reduce watering immediately and improve soil conditions. Fungicides are rarely effective once symptoms are visible above ground, as the root damage is already extensive.
Needle Blight Management: Prune out and destroy affected branches well back into healthy wood. Sterilize your pruners between cuts with a bleach solution. Improve air circulation by thinning dense growth. Avoid overhead watering.

For Physical Damage and Care

Pruning Right: Always prune yews in early spring before new growth starts. Only cut back into areas with green needles. Never shear into brown, leafless wood expecting it to regrow.
Fertilizing Wisely: Use a balanced, slow-release fertilizer in early spring if a soil test indicates a deficiency. Over-fertilizing can harm roots and promote excessive, weak growth that’s suceptible to pests.
Animal Deterrence: Use physical barriers like deer fencing or tree guards for voles. Repellent sprays can offer temporary protection but need frequent reapplication, especially after rain.

Can Brown Yew Needles Turn Green Again?

No, once a yew needle turns brown, it is dead and will not recover its green color. The goal is to save the remaining healthy growth and encourage new green shoots to fill in over time. Carefully prune out the dead brown branches to improve the plant’s appearance and health.

Prevention is the Best Medicine

Keeping your yews healthy from the start is easier than fixing problems. Choose a well-drained site with partial to full sun. Plant them properly, not too deep. Water consistently during establishment and droughts. Apply mulch. And monitor them regularly so you can catch any issues early, when they are most treatable.

FAQ

Q: Why is my yew turning brown from the inside out?
A: This is often natural, older needle drop, which happens periodically. However, if it’s excessive, it could be due to not enough light in the interior or stress from drought.

Q: Why are my yews turning brown after pruning?
A: You likely pruned too late in the season, cutting off new growth, or you cut back into the old wood where there are no green buds. Yews need green growth left on the branch to regenerate.

Q: Can a brown yew be saved?
A> It depends on the cause and extent. If the roots are healthy and the main stems are still alive (scrape the bark to check for green), it can often recover with corrected care and time. If the entire plant is brown and roots are rotted, it may not be salvageable.

Q: Is a yew turning brown always a sign of disease?
A: No, often it’s an environmental issue like winter burn or drought. Always check soil moisture and site conditions first before assuming it’s a pest or disease. Proper diagnosis is crucial for the right treatment.