What to Do in the Garden in April

April is a busy month for Midwest gardens: Time to finish any cleanup of winter debris, prep the soil for the growing season, plant cool-season crops, and spend time planning and designing your garden for the coming growing season.

Create New Beds

Dig Beds or Make Raised Ones

Dig new beds and borders as long as the soil isn't too wet; you can ruin the texture of the soil by creating muddy clumps and clods. If your soil isn't very good (too much clay or sand, for instance), create raised beds that you can fill with commercial topsoil. They're the smartest solution to problem soil.

Cleanup and Prep

Stop Weeds Before They Grow

Apply an organic weed-killer or another preemergent weed killer to your flowerbeds and borders. This prevents seeds from germinating and dramatically cuts down on weeding chores later in the season.

Trim Perennials

Continue to cut back any perennials still standing. In larger gardens, this can be a big job. (A lightweight electric power hedge trimmer is excellent for this!)

Prune Cautiously

Avoid significant pruning on any spring- or early-summer-blooming trees or shrubs. You'll trim off developing flower buds. However, you can cut out damaged or diseased wood now or nearly any time of year.

Spray Fruit Trees

In the northern Midwest, spray fruit trees with dormant oil when the temperature is above 40 degrees. Dormant oil prevents scale insects, spider mites and other pests later in the season. You can also spray dormant oil on roses and other trees and shrubs that have been troubled by pests in the past.

Wait to Mulch

Delay mulching with wood chips and other weed-suppressing mulches until May and June, when the soil has had a chance to warm up. This is especially true in the northern Midwest.

Rose Care

When to Prune Roses

Prune roses once they send out tiny red buds that will turn into stems. Once the stems are about 1/2 inch long, the rose is pretty well out of dormancy and you can tell what wood is alive and what has been killed by winter cold.

When to Fertilize Roses

Give roses their first feeding at pruning time. If you like, use a combination granular-type fertilizer/insecticide.

Flower Garden Tasks for the Northern Midwest (Zones 4-5)

Plant Cool-Season Annuals

About six to eight weeks before your region's last average frost date, plant cool-season annual flowers, such as pansies, violas, lobelia, snapdragons and more. They thrive in cool weather and tolerate frost well. They're especially good in pots.

Divide Perennials

Divide and transplant most summer- and fall-blooming perennials. They'll have plenty of time to get established by bloom time. Wait to divide spring-bloomers until fall.

Add Trees and More

Continue to plant trees, shrubs and roses. You can plant both bare-root and container-grown types now.

Veggie Garden Tasks for the Northern Midwest (Zones 4-5)

Plant Cool-Season Edibles

Plant annual edibles such as parsley, cilantro, broccoli, cauliflower, onions, Brussels sprouts, perennial herbs and more, as well as radish and spinach seeds as soon as the soil is thawed and you can work it easily. Plant or transplant perennial edibles now, including strawberries, raspberries, rhubarb and asparagus; and plant potatoes—Good Friday is the traditional planting day in this part of the country.

Tasks for the Southern Midwest (Zones 6 and 7)

Plant, Plant, Plant

Plant just about anything outside after the last average frost date, including tender perennials such as marigolds and tomatoes. In the southern half of the Midwest, your last average frost date will be in the middle or end of the month.

Trees, Shrubs and Roses

Continue to plant trees, shrubs and roses. But don't plant bare-root types after the middle of the month. They need cool, wet conditions to take off.

Divide and Conquer

Divide and transplant most summer- and fall-blooming perennials. They'll have plenty of time to get established by bloom time. Wait to divide spring-bloomers until fall.

Summer Bulbs

Plant gladiolus corms, canna rhizomes, tuberous begonias and other summer-blooming bulbs.

Fertilize and Care for Lawns

Aerate if Needed

Consider aerating your lawn. For most lawns, it's helpful to do this every two or three years, depending on foot traffic, soil and grass type.

Fertilize

Apply a preemergent fertilizer on lawns with cool-season grasses, such as Kentucky bluegrass, when you see bright yellow forsythia bushes blooming. Treat warm-season grasses, such as Bermudagrass and zoysia, with preemergent fertilizer if you live in the northern half of the Midwest. (In the southern half of the Midwest, late March is the ideal time to do this spring "weed and feed" with warm-season grasses.)

Sow Seeds

Sow grass seed in patchy spots, keeping the areas well watered with daily waterings, if necessary.