As a rule, you should fertilize at least three times a year; spring, summer and early fall.
To hold either a round or square post plumb inside a post hole while you pack dirt around it, make up a couple of wedges of 2x6 about 30 in. long. Cut to length, then make an angled cut from a corner of one end to the center of the other end. Insert a wedge on each side of the post; they will adjust in the hole for either post size or hole size.
Pruning cuts should be made so that only branch tissue is removed and stem tissue is not damaged. At the point where the branch attaches to the stem, branch and stem tissues remain separate, but are contiguous. If only branch tissues are cut when pruning, the stem tissues of the tree will probably not become decayed, and the wound will seal more effectively.
Water new trees once a week, regularly, during the first season, with l0 gallons of water. More for large trees. Pour the water down the trunks so it goes into the root ball, not along the top of the ground. In addition, whenever the leaves droop down or it is very hot, water again and mist the tops with the hose. Do not fertilize the first year.
Before the temperatures start to dip toward freezing, be sure to disconnect hoses from outdoor water faucets and drain all excess water from them before storing for the winter to protect pipes from freezing. Close valves that lead to outdoor faucets and open the faucets outside to allow for drainage.
Nitrogen encourages leafy growth, often at the expense of flowers and fruit. Don't use high-nitrogen fertilizers on tomatoes, peppers, and eggplants prior to flowering.
Potted plants need to be fertilized, especially if in the same pot and soil for a long period of time. Many types of fertilizers are available and any may be used according to label directions. Select one which gives the best results for existing growing conditions. Do not fertilize dry plants as the roots may be burned. Water, then fertilize in a day or two. Resting house plants need no fertilizer.