There are measures people can take to protect their trees from serious damage.
Mountain Pine Beetle
This is the same problem that has killed so many pine trees throughout Colorado's forest.
It appeared along the Front Range in 2010 and is expected to be attacking trees again beginning in late July or August. Arborists anticipate it will impact every community from Monument Hill to Castle Rock, Parker, Aurora, Littleton, Arvada, Denver, Boulder, Windsor, Fort Collins and all points in between.
Pine beetles tunnel through trees. One tell-tale sign of their activity is sap oozing from the bark. As we know from the beetle kill in our forests, this is a serious threat that kills most infested trees.
Arborists agree that trees at most risk are Scotch pine and Ponderosa pine, with other pines also being at risk. The tree expected to be least susceptible is Austrian pine.
Once trees have been attacked, it's too late to apply the treatment.
Property owners need to be proactive to protect their trees before they become infested. Applying the proper treatment before trees are attacked should protect them for the remainder of the year.
Yellowing aspens and maples
An unusual and quite common sight this summer is maple trees and aspen tress with yellow leaves. Their leaves should not be yellow in July, and this discoloration is the sign of an unhealthy condition called chlorosis.
The leaves are yellow because they are missing the green pigment that produces food for the tree and that results in nutrient deficiency, primarily a lack of iron.
Silver maple, autumn blaze maple and aspen trees are the most effected by this condition which was brought about by the very dry winter followed by a very wet spring and early summer.
The best help for these trees is to apply a deep-root fertilizer that includes iron in the fall. This late season fertilization will help to make up for the iron deficiency and prepare the trees to enter their period of dormancy with the good nutrition that will see them through the winter.
Information courtesy Associated Landscape Contractors of Colorado, sponsors of the 9News WaterWise Garden and the 9News Kitchen Garden.
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