Warm enough to mulch those tomato plants

Chris Himmelwright
Pratt Tribune
It's warm enough now to mulch those tomato plants, writes Pratt County master gardener Chris Himmelwright.

Soils are warm enough now that tomatoes can benefit from mulching as long as the soils are not saturated with water. Tomatoes prefer even levels of soil moisture, and mulches provide such by preventing excessive evaporation. Other benefits of mulching include weed suppression, moderating soil temperatures and preventing the formation of a hard crust on the soil. Crusted soils restrict air movement into and out of the soil and slow the water infiltration rate.

Hay and straw mulches are very popular for tomatoes but may contain weed or volunteer grain seeds. Grass clippings can also be used, but should be applied as a relatively thin layer — only 2 to 3 inches thick. Clippings should also be dry as wet clipping can mold and become so hard that water can’t pass through. Also, do not use clippings from lawns that have been treated with a weed killer until some time has passed. With most types of weed killers, clippings from the fourth mowing after treatment may be used. If the lawn was treated with a product containing quinclorac (Drive), the clippings should not be used as mulch. If the weed killer used has a crabgrass killer, it likely contains quinclorac.

Deadheading flowers

Some plants will bloom more profusely if the old, spent flowers are removed, a process called deadheading. Annuals, especially, focus their energy on seed production to ensure that the species survives. If you remove old flowers, the energy normally used to produce seed is now available to produce more flowers. Perennials can also benefit by lengthening the blooming season. However, some gardeners enjoy the look of spent flowers of perennials such as sedum or purple coneflower. Also, the seed produced can be a good food source for birds.

Not all plants need to be deadheaded, including sedum "Autumn Joy," melampodium, impatiens, most flowering vines, Lythrum, periwinkle (Catharanthus) and wishbone flower (Torenia). Those that do increase bloom in response to deadheading include hardy geraniums, coreopsis, petunias, marigolds, snapdragons, begonias, roses, campanulas, blanket flowers, delphiniums, zinnias, sweet peas, salvia, scabiosa, annual heliotrope, geraniums (Pelargonium) and yarrow.

Deadheading is easily accomplished by removing spent flowers. With some plants, pinching between a thumb and finger can do this, but tough, wiry stems will require a scissors or pruning shears, according to Ward Upham.

Rust on hollyhock

Watch for rust on hollyhock. This is the most common disease on hollyhock and can cause serious injury as leaves are progressively killed through the summer. Look for yellow spots on the surface of the leaves and orangish to brown pustules on the underside. Infections can also take place on stems and green flower parts.

The first line of defense is to remove all hollyhock stalks, leaves and other debris in the fall and destroy them. Remove any infected foliage you see now. Just be sure the foliage is dry so you don’t spread the disease. Continue to remove diseased leaves as soon as they show spots. Try using a fungicide such as sulfur or myclobutanil (Spectracide Immunox or Fertilome F-Stop Lawn and Garden Fungicide) to protect healthy foliage. Note that sulfur may burn leaves if the air temperature is over 85 degrees within 24 hours of application. Follow label directions for timing and rate.

Pinching mums

Though some garden mums do not require pinching back, most varieties will benefit. Pinching is done by removing the top inch of growth by pinching it between your thumbnail and forefinger. You can also use a scissors or even a pair of hedge shears.

Pinching encourages lateral buds to break and grow, resulting in a shorter, sturdier and fuller plant. The first pinching is usually done when the mums reach 6 inches in height. Remove about the top inch of growth. A second pinching should be done when the new growth from the previous pinch reaches about 4 inches. Cut the new growth down by about half. We may have time for one more pinch, but maybe not, as the last pinch should take place around July 4. Pinching later than July 4 can delay flowering, resulting in a shorter time of flowering before frost kills the blooms.

* Compiled by Chris Himmelwright, Pratt County Master Gardener, from information from the Kansas State Research and Extension Office.