Pine Tree Diseases: How to Identify and Treat Common Pine Problems

Pine trees are tough. They grow in sandy soil, survive drought, handle cold, and live for centuries. But when a pine gets sick, it goes downhill fast. Unlike deciduous trees that can lose all their leaves and recover, a pine that loses its needles usually doesn’t get them back. The window between “something looks wrong” and “this tree is dead” can be as short as a few months.

If your pine tree is turning brown, don’t assume it’s dying. Normal seasonal needle drop (inner needles yellowing in fall) is often mistaken for disease. But if you see browning tips, wilting new growth, oozing sap, or entire branches dying, you may have a real problem. Here’s how to figure out what’s wrong and whether you can fix it.

Normal vs. abnormal needle drop

Before you panic, know what’s normal. All pine trees drop older needles every year. This is called seasonal needle shed or “fall needle drop.”

Normal: Inner needles (closest to the trunk, 2-3 years old) turn yellow and fall in September through November. The newest growth at branch tips stays green. This happens to every healthy pine every year.

Abnormal: New growth at branch tips turns brown. Entire branches die from the tip inward. Needles drop in spring or summer. Browning appears on one side of the tree or in patches. These patterns suggest disease, pests, or environmental stress.

If you’re not sure, check our general guide on how to tell if a tree is dead for assessment methods that apply to pines.

Needle diseases

Dothistroma Needle Blight

The most common needle disease on Austrian pine, ponderosa pine, and mugo pine. Red-brown bands form across infected needles, usually on the lower half of the needle. The needle tip beyond the band dies and turns brown while the base stays green, creating a distinctive “banded” look.

• Species affected: Austrian pine (highly susceptible), ponderosa pine, mugo pine, Scots pine
• Symptoms: Red-brown bands on needles, brown needle tips, lower canopy defoliation starting from inner needles outward
• Timing: Symptoms appear in late summer and fall after spring infection
• Treatment: Copper-based fungicide (Bordeaux mixture or copper hydroxide) applied when new needles are half-elongated (typically late May to early June). Two applications 3-4 weeks apart. Remove heavily infected branches.
• Cost: $15-30 for fungicide (DIY), $200-400 for professional spray on large trees
• Prognosis: Treatable if caught early. Trees can recover over 2-3 years with consistent fungicide treatment. Without treatment, repeated annual defoliation weakens the tree and eventually kills it.

Brown Spot Needle Blight

Primarily attacks longleaf pine but also hits Scots pine and other two and three-needle species. Yellow spots on needles enlarge to brown lesions surrounded by yellow halos. Infected needles drop prematurely.

• Species affected: Longleaf pine, Scots pine
• Symptoms: Brown spots with yellow halos on needles, premature needle drop
• Treatment: Copper fungicide when new needles emerge. Improve air circulation by thinning surrounding vegetation.

Lophodermium Needle Cast

Causes needles to turn yellow, then brown, then drop. Small black fruiting bodies (like tiny football-shaped dots) appear on dead needles. Most common on Scots pine, Austrian pine, and red pine.

• Species affected: Scots pine, Austrian pine, red pine
• Symptoms: Yellow-to-brown needles with small black fruiting bodies, heavy needle drop in spring
• Treatment: Chlorothalonil or copper fungicide applied in late summer (when spores are released). Two applications 3-4 weeks apart.

Shoot and branch diseases

Diplodia Tip Blight (Sphaeropsis)

One of the most destructive pine diseases in landscapes. New shoots (candles) emerge in spring, grow 1-2 inches, then stop and turn brown. The stunted, dead shoots with short, brown needles clustered at branch tips are unmistakable. Over several years, Diplodia works its way through the canopy from the bottom up.

• Species affected: Austrian pine (extremely susceptible), Scots pine, red pine, mugo pine, ponderosa pine
• Symptoms: Stunted brown candles in spring, resin-soaked shoots, tiny black fruiting bodies on cone scales and needle sheaths
• Timing: Infection occurs in spring when new growth is expanding. Symptoms visible within weeks.
• Treatment: Preventive fungicide (thiophanate-methyl or copper-based) applied as candles begin to elongate in spring, before needles push out of the sheaths. Repeat in 7-10 days. Remove and destroy infected branch tips.
• Cost: $20-40 for fungicide, $250-500 for professional treatment
• Prognosis: Manageable with consistent annual treatment. Without treatment, the tree declines over 5-10 years. Severely infected trees (>50% canopy loss) are unlikely to recover.

Austrian pine was once the most popular landscape pine in the eastern US. Diplodia tip blight has made it almost unplantable in many areas. If you’re considering an Austrian pine, know that annual fungicide treatment may be necessary.

Pitch Canker (Fusarium circinatum)

A devastating disease of Monterey pine and other California coastal pines. Resinous cankers form on branches and trunk, oozing pitch. Branch tips die back progressively. No effective chemical treatment.

• Species affected: Monterey pine, Bishop pine, shore pine, Aleppo pine
• Symptoms: Pitch-soaked cankers on branches, dieback from branch tips, heavy resin flow
• Treatment: No fungicide treatment available. Prune dead branches 6 inches below visible infection. Sanitize tools between cuts.
• Prognosis: Many trees survive with reduced canopy. Some trees show natural resistance. Severely infected trees may need removal.

Trunk and root diseases

Pine Wilt Disease

The most rapidly fatal pine disease. Caused by the pinewood nematode (Bursaphelenchus xylophilus), transmitted by pine sawyer beetles. An infected pine goes from healthy to dead in weeks to months. The nematodes clog the tree’s water-conducting tissues, causing the whole tree to wilt and turn gray-green, then brown.

• Species affected: Scots pine and Austrian pine are most susceptible in the US. Japanese red pine and Japanese black pine are also highly vulnerable. Native North American pines are generally resistant (the nematode is native here and our pines co-evolved with it).
• Symptoms: Rapid, uniform browning of the entire tree. Needles turn gray-green, then brown, but don’t drop immediately. Resin flow stops (a healthy pine oozes resin from wounds; a nematode-infected pine doesn’t).
• Timing: Symptoms appear from late summer through fall. Trees infected in spring die by August or September.
• Treatment: None. There is no cure for pine wilt. Infected trees must be removed and destroyed (chipping or burning) before April to prevent sawyer beetles from emerging and spreading the nematode to nearby pines.
• Prevention: Don’t plant Scots pine or Austrian pine in areas where pine wilt is active (much of the eastern US from Nebraska east). Plant resistant native species instead.

Annosum Root Disease

A fungal root rot caused by Heterobasidion annosum. Spreads through root contact between adjacent trees and through fresh stump surfaces. Causes progressive decline, resin-soaked roots, and eventual death. Most common in managed pine plantations but also affects landscape pines.

• Species affected: All pine species, particularly loblolly, slash, and white pine
• Symptoms: Slow decline, sparse crowns, small needles, resin at the base, conks (bracket fungi) on roots and lower trunk
• Treatment: No cure for infected trees. Prevent spread by treating fresh stumps with borax (sodium borate) immediately after cutting. This blocks fungal colonization of the stump surface.

Rust diseases

White Pine Blister Rust

A devastating rust that cycles between five-needle pines (eastern white pine, western white pine, sugar pine, limber pine) and currant/gooseberry bushes (Ribes species). Orange blisters form on branches and trunk. Cankers girdle and kill branches. Trunk cankers can kill the entire tree.

• Species affected: Eastern white pine, western white pine, sugar pine, limber pine (all five-needle species)
• Symptoms: Yellow-orange blisters on bark in spring, branch cankers, crown dieback from top down
• Treatment: Prune infected branches at least 4 inches below the canker. Remove Ribes shrubs within 1,000 feet if possible (often impractical). No effective fungicide treatment for established infections.
• Prevention: Plant rust-resistant white pine selections when available. Avoid planting white pines near wild currant or gooseberry bushes.

Western Gall Rust

Causes round, woody galls on branches and sometimes the trunk of hard pines (lodgepole, ponderosa, jack pine). The galls weaken branches and can lead to breakage. Not usually fatal but disfiguring.

• Species affected: Lodgepole pine, jack pine, ponderosa pine, Scots pine
• Treatment: Prune infected branches below the gall. No fungicide treatment available.

The bark beetle connection

Bark beetles are the most common killers of pine trees in North America. They’re not diseases, but they work hand-in-hand with diseases. A pine weakened by disease, drought, or root damage sends out chemical distress signals that attract bark beetles. The beetles bore into the bark, introduce blue-stain fungi, and finish the tree off.

Common pine bark beetles include mountain pine beetle, southern pine beetle, western pine beetle, and Ips engraver beetles. Signs of bark beetle attack: boring dust in bark crevices, small round entry holes, pitch tubes (blobs of resin) on the trunk, and rapid crown browning.

A healthy, well-watered pine can repel bark beetles by flooding entry holes with resin (called “pitching out”). A stressed pine can’t produce enough resin to fight back. This is why keeping your pines healthy through proper watering and avoiding root damage is the single best defense against both disease and beetles. For more on boring insects, see our tree boring insects guide.

When to call an arborist

Call an ISA-certified arborist if:

• The entire tree is browning rapidly (possible pine wilt, which requires immediate removal)
• You see bark beetle entry holes or boring dust
• Large branches are dying and you’re not sure why
• The trunk has cankers, oozing resin, or fungal conks
• You need professional fungicide application for a large tree

An arborist can identify the specific disease, determine whether treatment is worthwhile, and apply professional-grade treatments that aren’t available to homeowners. Consultation costs $75-200. That’s worth it to avoid misdiagnosing and losing a tree. For help finding a qualified professional, see our arborist guide.

Prevention is everything

Most pine diseases exploit stressed trees. Keep your pines healthy and you prevent most problems:

• Water during drought. Deep soak pines once a month during extended dry periods, even established trees.
• Don’t wound the bark. Lawn mower and string trimmer damage opens infection points. Keep mulch around the base. Our tree sapling protection guide covers trunk protection methods.
• Prune correctly. Avoid pruning pines in wet weather. Make clean cuts. Sanitize tools between trees.
• Choose the right species. Don’t plant Austrian pine or Scots pine in areas with Diplodia or pine wilt. Plant native pines adapted to your region instead.
• Avoid overhead irrigation. Wet needles promote fungal spore germination. Use drip irrigation or water at the base.

Pine trees give you decades of green, year-round structure, and screening for minimal maintenance. The key is picking the right species for your area and keeping it healthy enough to fight off the problems that come. For more on diagnosing tree health issues, see our tree fungus guide and mklibrary.com’s guide to protecting your landscape investment.