Help a Tree - Remove Grass
Don't let grass grow beneath your trees. Grass competes fiercely for available water and will slow the growth of trees, especially newly planted ones. For instance, if the growth of a tree is reduced by 20 percent for one year because of grass competition, the growth automatically is 20 percent less during the second year's growth. Grass competition alone reduces tree and shrub growth by as much as 50 percent.
Do not let mulch touch the base of the tree, continue to keep it at least 3 inches from bark. Continued contact with any kind of mulch can cause disease or attract damaging insects.... ...»
If you plant flowers or other low growing plants at the base of the tree, be watchful of root locations and again keep them away from trunk of tree.
For those with problems with their pines, check tree for any insects. There are several kinds that will damage and eventually kill pines.