Diseases of Pine Trees

A close up of a pine tree's needles

Article by John Fech from March 14, 2018 Tree Service Magazine

Pines grow in most every state of the U.S., and are planted for many reasons. They offer year-round color, protect homes from wind and snow, subtle fragrance, harborage for wildlife and a great backdrop to help show off ornamentals planted in front of them. Unfortunately, they are susceptible to several maladies.

It’s important to keep pines viable by providing good tree care especially in two areas, separating trees from turf and proper planting procedures. These basic, but foundational factors are all-important and should always be a reference point when diagnosing tree maladies such as ones on pines.

Separation & Planting

Why are separation and planting so important? There are many reasons, but perhaps the most influential is that these are implementations that get a tree off to the best start possible if done correctly and mistakes that can’t be corrected if not.

Separation – This means designing or re-designing the landscape so that the trees are here and the turf is over there. Think about it. Trees are woody, while turf is herbaceous. Turf usually receives moderate to high volumes of water and fertilizer, and requires mowing. When trees are growing in a co-located landscape setting, they are usually over fertilized and over watered, and constantly run into with lawn mowing equipment; not a healthy environment.

Planting – Good planting practices include: digging a wide but shallow hole, pulling tangled roots apart, placing the root mass such that the uppermost lateral root is even with or slightly above grade, using existing/native soil instead of amended soil to backfill around roots, watering thoroughly to settle the roots, placing wood chip or pine needle mulch over the roots but not the bole and checking the soil moisture weekly to make sure that it’s moist but not soggy or dry. These are all important parts of the process. Way, way too many times trees are planted too deeply, in heavily amended soils, watered once and forgotten, covered with rock mulch and planter boxes built over the roots and more — these practices prevent tree success.

Diseases

Diseases are not just biological — it’s both — pathogenic and abiotic causes that challenge the overall health of pines. Regular scouting, often referred to as monitoring will help identify possible concerns that are site related (mower blight, leaving stakes on too long, deep planting, over mulching, etc.) and ones that are caused by fungi, nematodes and bacteria. Inspection packages go a long way toward avoiding tree troubles.