The Garden in April

April is a busy month for gardeners in the South. Much work must be done if gardens are to look their best this season. Gardeners don’t mind, however, for doing the work is one of the pleasures of gardening.

•Lawns

As soon as the lawn is completely green, it can be fertilized with a fertilizer with a high first number (nitrogen), a low middle number (Phosphorus) and a last number (Potassium) that is about half as large as the first number such as 16-4-8, 12-4-8, or 26-0-13. About half the nitrogen should be in slow release form, and one pound of actual nitrogen should be applied per thousand square feet of lawn.

Centipedegrass, bahiagrass, and carpetgrass are low fertility grasses. They will grow best and have fewer problems when fertilized only once (twice at the most!) a year. St. Augustine usually does best with a spring and summer application.

Maintain St. Augustine lawns at 2.5 to 4 inches tall and centipedegrass at about 1.5 to 2.0 inches. Mow frequently so that no more than one-third of the grass blade is removed per mowing.

Water only as need is evidenced by folding of leaf blades, graying of color, or when footprints remain for an extended period of time. Then water deeply.

•Perennials and Annuals
April is one of the best times to plant tender annuals. Frost is surely a thing of the past, and many are available at garden centers. Though it is not too late to plant seeds, most of these plants can be purchased ready for transplanting into the landscape.

Before planting annuals, add compost, peat moss, or other organic matter to the soil. Dig or till in thoroughly. Sprinkle the ground with slow-release fertilizer, and spread organic mulch such as bark chips or pine needles over the entire bed. Water thoroughly. When you are ready to plant your annuals, rake aside the mulch and plant so that the top of the soil around your plant is level with the soil in the prepared bed. Do not allow mulch to touch the stems of newly planted annuals. Water again after planting, and every day or so until plants are established.

Gradually decrease the frequency of watering until the plants are able to make it on a once-a-week deep watering.
Plant seeds of annual vines such as moonflower, hyacinth bean vine, Malabar spinach, cypress vine, cardinal vine, morning glory, and love-in-a-puff. Soak seeds overnight or until they have swollen and absorbed water. Germination will be quick, and they may be planted in containers or directly in the ground.

Plant bulbs such as achimines, walking iris, gingers, agapanthus, crinums, gladiolus, lilies, society garlic, canna, dahlia, gloriosa lily, and lycoris. Enjoy amaryllis and iris as they bloom this month. Fertilize spring bulbs with a bulb fertilizer such as 5-10-10.

Plant daylilies, lantana, verbena, salvias, sedum, purple coneflower, rudbeckia, and summer phlox. Include some ornamental grasses, gingers and in shady places try aspidistra or ferns. Divide and transplant fall-blooming perennials such as aster and chrysanthemum.

•Container Plants
Start hanging baskets and containers this month. Choose a spiller or trailing plant to tumble over the sides of the container, a filler to flesh it out and a tall, stunning plant (the thriller) for a combination that is sure to please. Try a container for butterflies and hummingbirds, or plant an assortment of herbs to enjoy all summer.

Crowded houseplants will need to be repotted. If you wish the plant to stay the same size, prune the top and the roots and replace it in the same container. Fill in around the roots carefully with fresh soil. If you wish the plant to grow bigger, move it up to a pot about 2 to 3 inches larger than the one it was in.

After evaluating and taking corrective measures, be sure to select a site suitable for the plants. Most will appreciate a place in shade. At any rate, never place a plant that has been indoors all winter in direct sunlight. The leaves will burn and it will take them a long time to recover. If the plant is tolerant of sun, acclimate it gradually to increasing light. Water the plants on a regular basis, and give them a bit of slow-release fertilizer for a perfectly thrilling summer vacation.

Marie Harrison is a Master Gardener Volunteer with the University of Florida IFAS Extension in Okaloosa County. Her books, “Gardening in the Coastal South,” “Southern Gardening, an Environmentally Sensitive Approach,” and “Groundcovers for the South” are now available. Visit her at her Web site www.mariesgarden.com to read gardening hints and other information of interest to gardeners.