Pine Trees Turning Brown: Causes and Solutions

If your tree is two to four years old, and it’s shedding less than ⅓ of its needles in autumn or winter, this is likely a seasonal event. Don’t fret! This is normal. The timing of the shedding is a key indication of whether or not it’s a seasonal cycle you’re dealing with. Also, knowing the species of pine you’re growing will help you determine if needle browning and drop is a common part of their life cycle.

If it’s occurring in spring after your last frost date, there could be something else going on. If not, there’s no need to try to prevent it or treat the tree. What you can do is use those pine needles in your garden. They make a great mulch that breaks down slowly. You can also rake them up and compost them if you choose to.

Just as you would with seasonal browning, think about the timing of the browning. If you’re in a drought, or it’s just after an unexpected snap freeze, or dealing with the effects of a flood, it’s possible the extremes are the culprit. Sometimes symptoms don’t appear for years after the initial stressor.

The best way to prevent your pine tree turning brown due to environmental stressors is to provide it with basic care. Ensure young trees are watered enough to help them establish strong roots. Give them the soil type they need at planting, and attend to them in all seasons.

Protect sensitive and young trees in cold or hot weather by watering ahead of a freeze or heat advisory. Cover smaller trees to prepare for snap freezes, and use tree wraps where necessary. Water ahead of freezes too.

Always plant your tree in proper conditions to prevent damage. This gives it the best chances of thriving in the years to come.

If you see your pine tree turning brown due to high heat, water it well in the morning around the drip line. Use drip irrigation during these times to ensure the water reaches deep into the ground at the tree’s roots. Loosen the soil around the tree if necessary, and add some compost to provide insulation. A bit of mulch helps too, but keep it away from the trunk.

For cold damage, wait for blackening to occur, up to several days after the freeze, and clip it off. Consult an arborist for larger trees. As you prune away cold damaged areas, cut at a 45-degree angle, and take care to make clean cuts. This prevents any diseases from taking hold.

In flooding, hold off on watering until the soil sufficiently dries. This gives the roots time to recover and prevents rot. Note that it can take time for symptoms to manifest after a weather extreme, and you might be dealing with browning needles in upcoming seasons.

Both pathogens cause needles of all ages to brown from the tips inward, leaving the inside of the needles green in earlier stages. Dothistroma needle blight occurs on the lower half of the tree, and presents itself in spring. Black fruiting bodies appear on the needle in later stages.

For brown spot, you’ll see the pine tree turning brown at any time of year, but most often in late summer to early fall. This browning occurs at any part of the tree, rather than at the base like it would with Dothistroma blight.

Maintain good air circulation around your pine trees to prevent overcrowding that increases the likelihood of fungal infections. If you decide to prune your pines, remove the bottom branches to prevent them from touching the ground where these fungi overwinter. Remove weeds from the area around the tree and mulch to limit water splashing. Ensure that your sprinklers don’t spray the needles of your tree.

Plant pine trees that aren’t as susceptible to these infections. Mugo pines (Pinus mugo) are resistant to blights. Keep all pines out of areas that are too low-lying, where fungi might proliferate.

Both blights can be treated with copper fungicides and pruning infected branches. But the timings of each treatment are different. For Dothistroma blight, treat your tree with a copper fungicide spray in late spring to midsummer. This protects new needles as they grow in, and attacks the fruiting bodies of the fungus.

Spray brown spot-infected trees in late spring to early summer, and follow up with two more treatments at intervals of two to three weeks. If rain is common during this time, shorten your interval to ensure proper coverage of the tree.

Both needlecasts present in spring, but you can tell them apart by football shaped fruiting bodies that look like black spots all over the needles. If you see these, you’re dealing with Lophodermium rather than Lophodermella.

Lophodermella needlecast causes trees to take on a lion-tailed appearance, with bare bases and tufted tops.

Much like other fungal diseases, planting the tree in proper conditions is your first line of defense against both needlecasts. Remove branches that crowd other trees or the canopy. Always plant pines in well-draining soil.

There aren’t many organic options for treating Lophodermella needlecast. Experts recommend using chlorothalonil-based fungicides, and applying when needles are half-grown and then once again when growth ceases for the year.

For Lophodermium needlecast, treat in midsummer to early fall. Same thing goes here: there aren’t organic options, and chlorothalonil-based fungicides are the recommended route. Contact an arborist to treat trees taller than 10 feet in both types of needlecast.

All of these bark beetles have a similar cylindrical appearance, with an elongated abdomen, short thorax, and even shorter head. They look similar to click beetles. Depending on the species, the tree may show damage at the entire or mid-trunk, or all over the tree in the branches.

Look for exposed cambium layers with boring trails throughout. Some make galleries in the trunk as they enter through the bark layer. Ips in particular make wishbone-shaped tunnels. As mentioned above, damaged trees take on browned needles that eventually turn red.

The best way to prevent boring beetles is to plant trees adapted to your region. Native pines will already have the resiliency to withstand attacks in small numbers. Planting in proper conditions is your first strategy for any potential pine problems.

Depending on the species, treatments are different. However, many bark beetles are difficult to control with insecticides due to their tendency to seek shelter in between the bark and the cambium of the tree. It’s best to consult an arborist to determine the best path forward.

If you’re trying to determine whether or not your tree has canker, look for lesions that girdle tree branches and trunks. Needle clusters fall off the tree, leaving the ends bare. In advanced infections, large sections of the tree die back, usually in the crown. Seedlings that contract the disease usually die.

The key symptoms of canker are oozy pitch, and protrusions that may excrete cloudy sap. Total tree death can occur, but isn’t the most likely outcome, as trees often recover.

Ips are a vector of the disease, so monitoring for them and consulting an arborist if you notice them is a good line of defense. Always plant seedlings from reputable sources, and avoid planting any stock known to have been near infected trees.

If you know of infected trees that died from canker, consult your local extension office to determine the best route for disposal. This prevents spread to other trees.

Since each lesion is its own infection, pruning with sterile loppers is a good treatment. Always completely sanitize your tools between cuts to prevent spreading the fungus around. In stands where the disease is prevalent, insecticides and fungicides aren’t viable routes for treatment, however, so avoid using them.