Junipers are tough, so when one starts dying there is usually a clear reason. Clemson Cooperative Extension says improper planting, environmental stress and several diseases and insects can cause needle browning, branch dieback and decline. Saving the plant depends on finding which one it is, and on acting before the browning spreads to most of the plant.

Table of Contents

The short answer: inspect the whole plant before treating anything, as Clemson advises, because browning can come from drought, overwatering, root injury or disease. Check that the soil drains: Phytophthora root rot in wet soil cannot be cured. Look for bagworm bags, and tap branches over white paper for spider mites. Prune out blighted tips. Water deeply in dry spells, but do not keep the soil wet. If most of the plant is brown, it will not grow back.

Step 1: Check how much is still alive

Junipers do not regrow from bare, brown wood. University of Wisconsin-Madison Extension says junipers should not be cut back to older, non-leafy areas, because new growth would take years to cover them. Scratch a few brown twigs with a fingernail: green, moist tissue underneath means the twig is alive; dry and brown means it is dead.

If browning is limited to some tips or a few branches, the plant can often recover. If most of the plant is brown, replacement is usually more practical.

Step 2: Check the soil and roots

Clemson says junipers need full sun and well-drained soil, are adapted to heat, drought and poor soils, and need minimal irrigation once established. That makes wet soil one of the biggest threats.

Clemson calls Phytophthora root rot one of the most destructive juniper diseases and says it is most common in poorly drained soils. The water mold thrives in saturated soil and infects roots, stopping the plant from taking up water and nutrients. Once symptoms develop, Clemson says, it cannot be cured, and preventive fungicides will not cure infected plants.

What to do:

Dig a small hole near the plant after rain. If water stands in it for hours, the site drains poorly.
Stop any automatic irrigation that keeps the soil wet, and redirect downspouts.
If the plant is badly affected, replant in a well-drained, sunny spot rather than in the same hole.

The opposite problem matters too, especially for new plants. Clemson says to water regularly until a juniper is established. The Morton Arboretum recommends watering deeply, so water soaks five to six inches down, rather than lightly and often, and continuing in fall until the soil freezes, because evergreens need ample water going into winter. See how much water a juniper needs.

Step 3: Look for insects

Pest	What to look for	What Clemson and Morton suggest
Bagworms	Small bags hanging from branches; stripped foliage	Hand-pick and remove bags; Bt sprays work on young caterpillars
Spruce spider mites	Discolored, browning needles, worst in cool spring and fall weather	Tap a branch over white paper and look for tiny moving specks
Juniper scale	Tiny scale insects on needles; gradual decline over seasons	Horticultural oil in late winter before new growth; target crawlers

Bagworms. Clemson says heavy infestations can defoliate branches and kill entire plants. The Morton Arboretum explains that bagworms overwinter as eggs inside the mother’s bag, with up to a thousand eggs per bag, and that caterpillars hatch in early June in northern Illinois. Picking off bags in fall, winter or early spring removes the next generation before it hatches. Clemson says products containing Bacillus thuringiensis (Bt) control young caterpillars with little impact on many beneficial insects.

Spider mites. Clemson notes spruce spider mites are cool-season pests, most active in spring and fall, that suck sap and cause browning and decline. Hold a white sheet of paper under a branch and tap it; mites show up as moving dots.

Scale. Clemson says juniper scale can kill a juniper within two to three growing seasons if unmanaged. It recommends a 2 to 3 percent horticultural oil spray in late winter or very early spring before new growth begins, and warns not to apply oil to drought-stressed plants or above label temperatures.

Step 4: Deal with tip blight

Clemson says Phomopsis tip blight infects branch tips smaller than a pencil, mainly tender new growth, and is most common in warm, wet weather in spring and early summer. Kabatina tip blight looks similar. To manage them:

Prune out and dispose of infected branches promptly. Cut back to healthy green growth, ideally to a side branch.
Avoid overhead irrigation, which keeps foliage wet.
Give plants room. Clemson says proper spacing improves airflow and reduces the long periods of leaf wetness that favor fungal infections.

Clemson also recommends resistant cultivars when replanting; it lists several, including ‘Wiltoni’ (‘Blue Rug’).

Step 5: Prune correctly

When you remove dead or damaged growth, follow Wisconsin Extension’s advice for junipers: prune selectively back to a side branch so cuts are hidden under foliage, do not shear back into bare wood, and do not prune after August, because late growth will not harden off before winter. See when to prune juniper trees.

Step 6: Reduce stress going forward

Sun: Clemson says junipers require full sun. A juniper that has become shaded by growing trees thins out. See whether junipers grow in shade.
Space: know the mature size and give the plant room, Clemson advises, so you do not have to cut it back hard later.
Water: deep, occasional watering during drought; no soggy soil.
Fertilizer: Clemson says established junipers need minimal fertilization; feeding will not save a plant with root rot or pests.

When a juniper cannot be saved

Remove the plant if most of it is brown, if root rot is confirmed in a site you cannot drain, or if browning keeps spreading after you have corrected water and pests. For more on causes, see why junipers turn brown and what kills juniper trees.

Key takeaways

Inspect the whole plant first; browning has several causes.
Check drainage: Phytophthora root rot in wet soil cannot be cured.
Look for bagworms, spider mites and scale, and treat each at the right time.
Prune blighted tips back to healthy growth; never cut into bare wood.
Junipers need full sun, good drainage and deep but infrequent water.

Sources

Juniper Diseases & Insect Pests, Clemson Cooperative Extension
Juniper, Clemson Cooperative Extension
Pruning Evergreens, University of Wisconsin-Madison Extension
Bagworms, The Morton Arboretum
Watering Trees and Shrubs, The Morton Arboretum

Top photo: Lukas from London, England, CC BY-SA 2.0, via Wikimedia Commons

How to Save a Juniper Tree from Dying