LADYBUG: DURING HOT WEATHER, CUT BACK PETUNIAS

Are you looking at petunias that are 16 inches tall with a few flowers perched atop of "leggy" almost-leafless stems? What happened to the beautiful, compact, leafy plant you bought last spring?

The petunia is still a popular bedding plant, although now surpassed by impatiens and vinca as more practical for our hot summers. Most gardeners buy their petunias in early spring, plant them and enjoy a flowering garden until midsummer when the plants become leggy, fall over and remain an unattractive spectacle until frost.

A few simple tips can turn that brown thumb green and your garden will flower all summer. Petunias are "thermophotoperiodic." That is, their growth habit responds according to the temperature and amount of daylight. At 62 degrees, the plant will be branched, bushy, compact and multi flowered.

From 62 to 75 degrees, the growth habit will vary depending on day length. Under short days (fewer than 12 hours of daylight), the plant will grow single-stemmed with only one flower. At temperatures above 75 degrees, the plant will always be tall and leggy with a single flower.

This is why hot weather takes its toll on petunias -- and now is the perfect time to cut back for future bloom.

A bit of this and that

Many gardeners ask when to water their plants. If any is to be done, the best time is in the morning or early afternoon, giving ample time for plants to dry before sundown. If plants are wet overnight, fungus problems may occur. Water enough to soak the root area, but no more than once or twice a week. During our extreme hot weather, it has been necessary to water container plantings and hanging baskets more than once daily.

Picking flowers frequently encourages most annuals to flower even more abundantly.

Flowers planted around trees help protect them from lawnmower injury. When you water the flowers, water deeply to help keep the tree healthy during dry periods, also. Be sure to choose shade-loving annuals such as impatiens, begonias, coleus and cladiums.

Why grow annuals? Because annuals are easy to grow, quick to bloom, flower continuously, and make beautiful cut flowers to bring inside. Hundreds of varieties are available in almost every color imaginable, with new ones being introduced each year. So, if you want a colorful landscape, plant annuals. This year we have had excellent luck with vinca and lisianthus, but at the first frost they will be the first to go.

If you have annual and perennial flowers growing in the garden and do not know which is which, here is the difference: Marigolds, petunias, zinnias and others are annuals, and will flower continuously until autumn; mums, bleeding hearts, coral bells and others are perennials because they reappear year after year.

Coreopsis is the perfect flower for gardeners who like lots of blossoms with little work. All that is needed is sunshine and well-drained soil, and coreopsis will last for years. The daisy like blooms appear throughout the summer and make beautiful cut flowers.

Lavender and heliotrope are among the most fragrant perennials. For centuries lavender's flowers have been used for making perfumes and potpourris. The pink blossoms of garden helitrope are prized as perfume, cut flowers. Both like sun and well drained soil.

Salvia is the brightest colored red flower around, although it is also in purple, dubonnet, salmon, lilac and white now. (Still prefer the red called Red Hot Sally.) Bright red spikes bloom all summer until frost. It is possible to encourage the spreading of the plant by nipping off the spikes as it spreads. Freshly cut spikes are ideal for flower arrangements.

Continue to deadhead perennials, especially phlox, foxgloves, poppies, and coreopsis so as to discourage seedlings.

Sheer back bedding plants. Give them a boost with soluble fertilizer to keep them blooming until frost.

If August is hot and dry, lacebugs and spider mites are bound to show up. Horticultural oil and insecticidal soap are less toxic than Orthene, Durban or Malathion.

Keep an eye out for caterpillars, four-lined bugs, aphids, beetles and other insects. If treatment is necessary, try insecticidal soap or Pyrethrin before bringing out the "big guns."

Check winter creeper and packysandra for euonymus cale -- tiny white flecks on stems and underside of the leaves. Insecticidal soap will kill emerging crawlers.

It is never too late to mulch trees, shrubs and flower beds. Wait until after a good rain, then apply 2 or 3 inches of compost, straw, pine needles or chopped leaves, depending on the application.

A Florida friend has sent the garden section from St. Petersburg Times. It is interesting to note how different Florida gardening is than ours in the Midwest. They need to cut back their annuals many times during the growing season and water and fertilize more.

~Mary Blue is a resident of Cape girardeau and an avid gardener.