Sometimes arborvitae run into a few quiet arborvitae issues, the top of arborvitae turning brown, a branch drying out, or a few leaves fading. These are common problems with arborvitae, and they’re usually easy to correct once you know what’s behind them. With the right care, even arborvitae shedding or arborvitae brown on one side can recover over time.
In general arborvitaes exhibit few serious insect and disease problems. Unfortunately American and Oriental Arborvitae are considered ice cream by deer and are quite vulnerable to deer browsing especially in the winter months.
Leaves Drop Off In Spring or Fall
Normal Leaf Senescence All evergreens drop some of their foliage every year, usually in the fall, but it can occur in the spring as well. Do not be concerned if you notice some brown, dead leaves on arborvitaes at the same time the deciduous trees and shrubs are displaying their fall colors. This normal reddish-brown discoloration occurs on branches closest to the trunk. Subsequent leaf drop may occur annually or every second or third year. However, if brown foliage appears at other times of the year or on leaf tips, the plant may have spider mites or be suffering from an environmental problem.
Plant Loses Its Shape
Old Age Harsh weather may cause some branches and even trunks of older arborvitaes to break off, making unsightly gaps in the form of the shrub. If pruning does not improve the shrub's appearance it may be time to replace it.
Twigs, Leaves Turn Brown During Drought
Sunscald or Sunscorch A shortage of water in summer may cause twigs to turn brown and eventually drop off. During the summer, soak the soil to a depth of about two feet once every two weeks or so. If the symptoms develop in late winter or early spring, they may be caused by drying winds and hot sun. They are hard on the previous season's growth and recently transplanted shrubs in exposed locations are most severely affected. In hot sun water evaporates from the leaves faster than the root system can replace it, which causes the leaf discoloration. Minimize damage by mulching and thoroughly soaking the ground around the shrubs before the ground freezes in winter. Spray the foliage of arborvitae in exposed sites with an anti-transpirant spray in the fall to protect it from drying out during the winter. Follow label instructions.
Foliage Browns, Trunk Splits Near Soil means Freeze Injury
Freeze Injury Normally arborvitae gradually acclimate to increasing colder temperatures as fall yields to winter and are able to withstand winter successfully. In some cases a prolonged warm fall, followed by a sudden cold spell or a warm spell in the middle of winter prevents normal gradual acclimatization and plant tissues freeze and die, killing it. While there is nothing to be done about the weather, you can control the arborvitae's environment somewhat. Avoid feeding with high nitrogen fertilizers late in the season and be sure that arborvitaes are planted in well-drained soil.
You may also notice white spots on arborvitae or even signs of rust on arborvitae. These often come from mild fungal diseases of arborvitae or tiny arborvitae pests that thrive in damp weather. Trim damaged areas and allow more air between plants to stop the spread.
For more information see the file on Dealing With Winter Injury To Trees and Shrubs
Foliage Chewed, Striped From Twigs
Deer, Moose, Rabbits Unfortunately arborvitae foliage is tasty to several critters. As the pressure of development restricts their habitats even more severely than ever before, wildlife is forced to feed in residential landscapes. Here they often find plants that are tastier than the wild ones they normally forage on. There are many animal repellent spray products for plant foliage available that discourage the casual browser by either smell or taste. They tend to be effective for only a short time, until the rain washes them off or the animal gets used to them. Often they are most effective if several are used alternately. Animals under severe population pressure and desperate for food can only be discouraged by a barrier of some kind.
An effective, unobtrusive fencing material is black polynetting that can be easily installed around the area where the arborvitaes are planted, or around the entire yard.
For more information see the file Controlling Deer or on Dealing With Rabbits
Small Silken Bags Hang From Twigs
Bagworms The bagworm caterpillar builds a silken cocoon, or bag, with silk and bits of leaves attached to the outside. It carries its bag with it as it feeds. These small spindle-shaped bags hanging from your arborvitae's branches like Christmas tree ornaments indicate its presence.
See the file on Controlling Bagworms.
Leaves Webbed Over, Turn Gray or Brown.
Spider Mites Spruce spider mites or red spider mites spin webs and cause a graying or browning of arborvitae leaves.
For more information see the file on Controlling Mites
Leaves Curled and Distorted.
Aphids The arborvitae aphid is a reddish brown, soft-bodied, pear-shaped sucking insect about the size of the head of a pin. Aphids suck plant sap from foliage, retarding or distorting arborvitae growth. Affected leaves may turn yellow or brown, wilt under bright sunlight, or sometimes curl and pucker. For more information see the files on Controlling Aphids
Sawdust at Base of Shrub, Poor Growth
Cedar Tree Borers In its larval stage, the Cedar Tree Borer bores into the inner bark and wood, frequently girdling the arborvitae, making it more susceptible to heat, drought, and disease. A mass of gummy sawdust ("frass") at the base of an injured arborvitae shrub signals the presence of borers, the larvae of the cedar tree borer.
For more information see the file on Controlling Borers
Leaves and Branches Encrusted With Small Bumps
Scale Insects Scale insects lurk under waxy shells, forming groups of small bumps or blister-like outgrowths on arborvitae stems and leaves. The shells may be white, yellow, or brown to black, and are about 1/10 to 2/5 inch in diameter. These bumps and discolored upper leaf surfaces, followed by leaf drop, reduced growth, and stunted shrubs, suggest a scale attack.
For more information see the file on Controlling Scale
Leaf Margins Notched
Arborvitae Weevils These weevils are small and black, covered with metallic green scales and fine short hairs. Their larvae (grubs), which are white to pink with brown heads, attack arborvitae roots from June or July to midwinter or the following spring. Then they emerge from the soil to feed on leaves from May to July. Notches appearing in the margins of arborvitae leaves probably means these weevils are at work. The adults usually are active at night and hide in soil and trash during the day. Adult weevils will "play dead" when disturbed, folding their legs and dropping off plants to the ground.
For more information see the file on Controlling Weevils
Twig Tips/Leaves Turn Brown Or Yellow, Die Back
Fungal Diseases In some cases the disease causes branch tips to turn brown and die back until the entire branch dies. Leaf spot causes leaves of affected shrubs turn straw yellow or brown and are thickly dotted with small black fruiting bodies. These diseases mostly attack foliage or shrubs already weakened by stress from heat, lack of water or other environmental problem. Sometimes the entire shrub may be involved.
For more information see the file on Controlling Fungal Disease
Foliage Burned
Dog Urine: Dog urine may discolor arborvitae foliage and even kill branches.
Also, when leaves turn dark or lose color, it may point to arborvitae black leaves or arborvitae drying out from stress or poor watering. In most cases, adjusting moisture and improving drainage helps your plants recover quickly.
For more information see the file Dealing With Dogs
When it’s more than a problem, signs your arborvitae is dying
Sometimes it’s hard to tell whether your hedge is doing fine or quietly failing.
Here are a few things you can check this weekend:
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Twig test: Gently pinch a twig. If it bends and is green inside you’re good. If it snaps clean and is dry/brittle it’s likely dead.
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Colour dive: A few brown tips here and there is one thing. But if the brown is spreading inward from the tips, or the leaves inside look grey or pale, that’s a step beyond normal stress.
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Look at the base: Healthy roots and trunk should feel firm and solid. If you see soft wood, mushy spots, or mushrooms at the base, the root zone could be failing.
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Check your soil & watering: Too dry or too soggy can both lead to decline. If the soil hasn’t drained since rain or you’ve had no supplemental water in dry spells, the shrub may be struggling.
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Pest & disease signs: You might see small webs, sticky honey-dew, odd growths or lots of brown spotting. These point to an attack.
If you spot one of these signs alone, your arborvitae might still bounce back with better care. If you’re seeing two or more, and it’s been like this for months, it may be time to act fast (or plan for replacement).
Don’t worry if you find some damage, trimming back the dead bits and giving attention to soil and water often gets your hedge moving again. But early action is always easier than big repairs later.
Still worried about your arborvitae?
Why are my arborvitae dying?
Arborvitae often die from watering mistakes, poor drainage, or root rot. Too much or too little water stresses the roots, while frozen soil and harsh winds add more damage. Check moisture, sunlight, and signs of pests before pruning dead wood. Early care usually saves them, learn more in our full guide on arborvitae problems.
What causes arborvitae to turn brown?
Browning happens when roots can’t balance water, from drought, soggy soil, or frozen ground. Sometimes it’s winter burn or pest activity. If only the inner needles turn brown, that’s often normal aging. Keep soil moist but not soaked, and check for pests or fungus if the browning spreads.
Why is my arborvitae turning brown in summer?
In summer, browning means water stress. Hot, dry air pulls moisture faster than roots can replace it. Water deeply once a week and mulch the base to hold moisture. If the soil feels soggy, improve drainage to prevent root rot. Consistent watering helps your arborvitae recover.
Why are my arborvitae turning brown on the bottom?
The lower branches may brown from lack of sunlight, dry roots, or normal seasonal shedding. If it’s just the inside or bottom, it’s often nothing to worry about. Keep watering steady and trim lightly to open airflow. Healthy new growth above means your arborvitae is fine.
Do arborvitae turn brown in fall?
Yes, it’s normal for inner foliage to turn brown in fall. This natural shedding helps the plant save energy for new spring growth. If outer tips brown instead, that signals stress from drought or shade. Keep watering until the ground freezes to prevent winter damage.
Do arborvitae shed in the fall?
Yes, arborvitae shed old needles each fall. The inner leaves turn yellow or brown and drop, just like evergreens renewing themselves. Shedding on outer branches, however, means stress or disease. Shake off loose needles and maintain regular watering for a healthy comeback next season.
How to tell if your Green Giant arborvitae is dying
Check for widespread browning, brittle twigs, and soft, soggy roots. If the browning starts from the top down, it could be drought or root rot. A flexible twig with green inside means it’s still alive. Water deeply, prune damage, and check for pests to help recovery.
Will dog pee kill arborvitae?
Yes, repeated dog urine can burn arborvitae foliage and alter soil pH. The salts and nitrogen are too strong, especially for small Emerald Green varieties. Water the area immediately to dilute it and block access with mulch or fencing. Quick rinsing often prevents lasting damage.
Before you go......
Most arborvitae problems look worse than they are. Whether it’s arborvitae turning brown inside, arborvitae brown tips, or minor diseases of arborvitae, steady care brings them back.
These forgiving shrubs can handle a lot, fix small issues early, keep an eye on your arborvitae leaves, and they’ll stay green and full for years.
