Avoid Working in Very Wet or Very Dry Soil
Soil that's too wet or too dry can be damaged by tilling or digging. Scoop up a handful of soil and squeeze it; if it holds together in a tight clump, it's too wet. If it won't hold together at all, it's too dry and needs to be watered. When the soil holds together in a loose clump that crumbles easily, it can be worked without ill effect.
Aerate the Lawn
If your lawn has become compacted or just needs rejuvenation, aerating can help. You can rent an aerator that rolls along and removes plugs from the lawn. Then fill a fertilizer spreader with compost and walk over the lawn so the compost falls into the aeration holes. Do this before a rain to eliminate the need to water afterwards.
Pot Up Cuttings
If you have any cuttings from coleus or other annuals that you've been wintering indoors, now's the time to pot them up so they have time to expand their root systems before moving outside in June. Pinch off any flowers that form to force energy into root growth.
Sow Lettuce in Containers
You can get an earlier crop of lettuce by starting seeds outdoors in a wide, shallow container. The soil will be warmer than the ground so the plants will grow more quickly. Make successive plantings both in containers and in the ground to extend the harvest.
Control Tent Caterpillars
Check apple, cherry, and other fruit trees for nests of tent caterpillars. They will emerge at the same time the leaves do. Blast nests with a strong spray of water to destroy them or spray them with Bt. Bt will harm only the caterpillars and not other beneficial insects, birds, or humans. You'll need a pump sprayer for this job.