April and May lawn care makes a big difference in the health of a lawn all year. Here are five questions and answers that look at the best spring practices, including special problems created by the winter of 2015.

1. Apply lime in early spring?

Some people automatically apply lime to raise the pH of our naturally acidic soil, almost as a rite of spring. But if you applied lime last spring or fall, it may not be needed. Only a soil test can tell.

When pH is correct, plants are able to consume fertilizer more efficiently and thrive. Turf grass, for instance, thrives in pH 6.5 to 7.2. When pH is too low, fertilizer applications may be partially or totally wasted.

If your lawn needs pH adjustment, fast-acting lime is worth consideration. It works in about six weeks, rather than the 12 to 14 months of conventional lime. Products such as Espoma’s Lighting Lime contain humic acid, which promotes a healthy soil food web. This product and others are compatible with organic growing. Other fast-acting lime products include Solu Cal, Encap, Agway, and Pennington’s.

Fast-acting lime has a higher price tag per pound, but before you conclude it is too expensive compare the application rates. The material goes farther and works faster. You’ll see the benefits this year rather than next.

2. Apply compost in spring?

Compost provides organic matter and has multiple benefits to lawns. It feeds soil microbes and improves the soil’s moisture-holding capacity. Given a few growing seasons, compost applications can improve pH imbalances. The microbes in compost help decompose thatch—without the rake.

A soil test will show the percentage of organic matter already in the lawn soil. The optimal amount is 4 to 7 percent

If needed, compost may be applied both spring and fall. The spring application, however, is the lesser of the two applications — usually about one-quarter-inch thick or less. There’s evidence that heavy compost applications in spring create favorable conditions for egg-laying beetles, which results in more grubs.

3. Aerate this spring?

The main purpose of aeration is to counteract soil compaction. Aeration helps lime, fertilizer, compost and other amendments reach grass roots. It also helps incorporate oxygen into soil. Grass grows denser in properly aerated soil, crowding out weeds.

While those are all excellent benefits in the spring landscape, the aeration process can stir up weed seeds and create openings for germination. For that reason, some people aerate lawns only in fall.

This year may be an exception. Particularly where ice covered the lawn for extended periods of time, soil may be heavily compacted. If you aerate this spring, follow with overseeding. Try a mix of 5 percent micro clover and 95 percent cool season grass, such as perennial ryegrass. Overseeding, done in late April or early May, encourages dense cover and crowds out the warm season weeds such as crabgrass.

4. De-thatch the lawn now?

Thatch is the collection of dead grass roots and other fine debris on the lawn. (It is not grass clippings.) When thatch is more than about half-an-inch thick, removal is recommended.

This can be done spring or fall, but if crabgrass plagues your lawn, consider waiting until fall. The vigorous raking involved in de-thatching can stir up crabgrass and other weed seeds. As mentioned above, compost applications help decompose thatch naturally without raking.

5. Bag clippings after the first mowing?

Because of the long winter and deep ice pack, some molds and diseases may be present in our grass this spring. Therefore, you may want to bag the clippings on the first mowing to remove mold spores. After that, leave grass clippings on the lawn to restore nitrogen to the soil.

Kathy Connolly is a landscape designer and speaker from Old Saybrook. She will conduct a seminar on meadow development May 30 in Middlefield. See SpeakingofLandscapes.com.