Pine trees are planted in the landscape for their ease of care and year-round green. The evergreens have come under attack in recent years by mutant fungi strains. As a result, the Scots pine is no longer recommended as a landscape plant by extension specialists due to its prevalence towards a specific fungi according to Iowa State University Extension. Not all fungi is deadly to pine trees, however, and may be treated.
Blue Stain Fungi
Blue stain is a common form of fungi that attacks pines, especially the Scots pine, in the United States. This fungi causes the needles of the pine to turn a grayish color before browning. resin flow in the wood ceases. Pine needles begin to drop as the disease spreads. The blue stain fungi wilt will eventually kill the tree.
Blight is another form of fungi that effects a wide variety of pines, including the Scots pine, Austrian pine, ponderosa pine and the mugo pine. It effects trees that are mature, usually between 25 and 30 years old. The current year's growth appears stunted and and turns brown. Dead limbs and stunted tree growth spreads throughout the tree until it dies.
Fungi requires a moist environment that is humid and cool to spread and survive. Long, wet winters as well as wind and rain create and carry spores to pine trees according to Purdue University Extension. Nematodes breeding in dying pines infected with the fungi may spread fungus to new trees as well.
Give regular care to your pine to prevent infection with fungus. Water the plant during prolonged drought periods to prevent the tree from weakening. Keep the soil loose by aerating it regularly. This improves drainage and prevents the moist conditions necessary for fungi to thrive. Remove any dead or dying branches from the tree. Fungi breeds in dying material.
Use fungicides to prevent and destroy fungus on a pine. Identify the fungus type on the tree to determine the correct fungicide required for control. Send samples of your tree to a local university extension for identification. Spray the fungicide when the buds of the tree break, when the candles of the tree are half grown, then again when the candles have expanded.