Gardeners generally plant annual flowers in the spring to get maximum benefit from their short lives. Perennials go in during the cool days of fall for maximum root development before the next growing season. It is possible, however, to rush the season on perennials and take advantage of July sales of leftover zinnias and snapdragons. There are also some bulbs and corms that can be planted right into early summer. Success with summer planting depends on the health and hardiness of flower plants and their after-planting care.
Deadhead and prune annual plants you purchase from late-season sales. Plant in the late afternoon or evening to minimize the time they must spend in summer sun and heat on their first day in the garden; if a period of cloudy and rainy weather is predicted, plant then to give your plants some protection from harsh summer sun.
Encourage fresh growth by sitting plants in soil up to the first true leaves on their stalks. New roots will grow around the first leaves, encouraging fresh top growth. If possible, time your planting just before a thunderstorm to capitalize on the nitrates added to the rain by lightning.
Give a boost to roots that have been cramped in a plastic pot; add a half-strength mixture of liquid garden fertilizer as a "transplant" solution in the planting hole before filling.
Water deeply and shade new transplants with newspaper or cardboard tents during intense, hot sun; annuals love sunshine, but your late transplants will droop in such conditions. Leave the tents on and water the plants early each morning until they perk up.
Plant perennials from the time they begin appearing in garden centers in late spring. Avoid mid-summer planting if possible; it is better to wait until late summer or early fall to ensure the perennials will develop strong roots and bloom vigorously the following year.
Deadhead flowering perennials and prune woody perennials lightly to stimulate branching. Herbaceous spring bloomers such as peonies should be planted without pruning---they need the foliage to make food for the next year's blooms.
Spray roots with water to keep them hydrated. Loosen roots by tapping the root balls of large plants such as daylilies and roses with a hand trowel.
Fill the hole halfway with soil and adjust the plant so that the crown sits exactly where it sat in its container. Water deeply before filling the hole. Shade and water each morning until the plant regains vigor.
Seeds and Bulbs
Plant seeds for late-blooming annuals in early summer; they may perform better than nursery sale plants if you live in an area with a growing season that extends into the fall. Choose fast-growing flowers that are fall-hardy, such as zinnias and marigolds. Shade seeded areas and keep them watered; summer soil is often too warm to allow some annuals to germinate. Bury seeds as directed on the package.
Plant biennial seeds in early or late summer for blooms next summer.
Plant tuberous begonias, fall crocus and meadow saffron in early summer for fall blooms.
Continue planting lycoris and gladiolus corms every two weeks until mid-summer for magic lilies and glads through the fall.
About this Author
Chicago native Laura Reynolds has been writing for 40 years. She attended American University (D.C.), Northern Illinois University and University of Illinois Chicago and has a B.S. in communications (theater). Originally a secondary school communications and history teacher, she's written one book and edited several others. She has 30 years of experience as a local official, including service as a municipal judge.