Begin Fertilizing Houseplants
As days grow longer and light increases, new houseplant growth begins. Foliage plants do best with a high-nitrogen fertilizer, while flowering plants thrive with a fertilizer higher in phosphorous. Among the easiest fertilizer to use is one that is water soluble and added each time plants are watered. The best fertilizer formulations do not use urea as a nitrogen source and include micronutrients. Magnesium in the formula helps keep leaves green.
Plant Cool-Season Crops
Transplant or direct-sow cool-season crops in the vegetable garden whenever the soil is dry enough to work. When squeezed, the soil should crumble instead of forming a ball. Some of the cool-season crops to direct-seed include peas, lettuce, spinach, carrots, beets, turnips, parsnips, and Swiss chard. Transplant cabbage, broccoli, cabbage, and cauliflower. In areas where spring is short-lived and hot temperatures come fast, choose varieties that mature quickly.
Fertilize Trees and Shrubs
The best time to feed trees and shrubs is before new growth begins but after soil temperatures have reached 40 degrees F. There are lots of fertilizer options available to gardeners, and the most important rule is to follow the manufacturer's directions. Apply granular fertilizers over the entire root area of the plant, which extends to the drip line. Although it's best to have the soil analyzed, a general rule of thumb for an all-purpose fertilizer with a formulation approximating 5-5-5 is to apply 5 pounds per 100 square feet.
Get Bare-Root Plants in the Ground ASAP
The container-grown or balled-and-burlapped plants available at nurseries and garden centers have made planting an "any time the ground can be dug" proposition. Nowadays, many mail-order companies ship plants in pots, but there are still ones that ship dormant bare-root plants. For the best success with these, it's important to get them either planted into the ground or into pots as soon as possible after they arrive and before hot weather arrives.
Start Warm-Season Vegetables and Herbs Indoors
The vegetables and herbs that are killed by a frost, such as tomatoes, peppers, eggplant, basil, and marjoram, usually take six to eight weeks from sowing to transplant size. Count back from your last frost date to determine the time to sow indoors. When starting seeds indoors, use a soilless mix designated for germinating seeds or one of the different types of soil cubes. Unless you have a very sunny window or greenhouse, plan on growing seedlings under fluorescent lights. Ideally, use a 2-tube fixture with one warm-white and one cool-white fluorescent bulb.