Backyard Gardener: Russian sage for the garden

Hello Mid-Ohio Valley Farmers and Gardeners! The September heat wave is hopefully the last blast of summer as temperatures again soar in to the nineties. It does not really feel like fall until the weather cools down a bit and the leaves have begun to turn color. Do not forget fall is a great time to soil test cropland, hay meadows, pastures and gardens to be certain what nutrients the soils needs. Application of lime, compost and fertilizer can also be done in the fall to improve soils for next season.

You need to have a starting point to work from if your goal is to improve soils and increase fertility. The only accurate way to determine how much lime and/or fertilizer your soil needs is to have your soil tested. WVU still has a soil testing lab and soil testing is a free service of the university. All you need to do is fill out the form accurately and pay for the postage to the WVU Souls lab. It is best to test soils in the fall, but soil testing can be done anytime. The WVU Soils Lab can be found at https://soiltesting.wvu.edu/home. The soil test form can be downloaded to print or you can contact the Wood County WVU Extension Office and we will be glad to assist you with your soil test.

This week I have a couple of topics to discuss; Russian Sage for the flower garden controlling corn earworm in sweet corn. Russian sage is a great perennial to add to flower beds around the home. It has a long bloom period starting in late summer, is resistant to drought and has attractive blue flowers. This semi-woody plant was named Perennial Plant of the Year in 1995. It actually resembles lavender, and can be used in areas too cold to grow lavender reliably. It is a member of the mint family and is hardy in zones 4-9.

The plant originates from the mountains of Central Asia but was named after the governor of a Russian province. The sage reference probably comes from the characteristic sage aroma given off when the leaves are crushed. It is an attractive plant with elongate, gray-green leaves and square, silvery-gray stems that produces an airy cloud of color late in the summer. The tiny, purple-blue, tubular flowers are arranged in whorls along long stems.

The species grows 3 to 4 feet tall, producing lavender blue flowers all summer on fine textured, aromatic, gray-green leaves and gray-white stems. It is quite drought resistant. The flowers are attractive to bees and other insects. Plant Russian sage in full sun and well-drained soil, spacing the plants about 18 inches apart. Container-grown plants are best planted in early spring, setting them at the same depth as they were in the pot, but they can be planted out through the summer until one month before a hard killing frost. Small plants may be slow to establish. Water regularly during the first growing season to establish a deep, extensive root system.

Once well-established, Russian sage can tolerate drought very well and is easy to grow, with essentially having no disease or insect problems. Good drainage and aeration will enable the plant to survive wet winters. Plants will rot if the soil is too moist. Leave the old stems on through winter and cut them down to about a foot in the spring to keep the plants from getting woody which can result in a reduction in foliage and flower quality. Fertilize before new growth begins in spring.

The corn earworm is the primary pest of sweet corn in West Virginia. Infestation levels in vary with the year, time of season, and location. Infestations of corn earworm result from migrant moths carried northward on storm fronts into the region during mid to late summer. The adult stage of this pest is a buff colored moth with a wing span of about 1¢ inches. The females prefer fresh corn silk on which to lay their eggs. When the egg hatches on corn, the larva will crawl down the silk and into the ear. Feeding starts at the tip of the ear and works down. Though several earworms may hatch and attack a single ear, only one is usually present at harvest as these insects are cannibalistic. Larvae may be light brown or green to nearly black with dark and light stripes running lengthwise on the body. For home gardeners, damaged ends of the sweet corn can be cut off.

Chemical control is a bit of a challenge as silks continue to grow over a period of time. This means that even if silks are treated, new silk will appear that hasn’t been protected. Applications every 2 to 3 days are needed for insecticides to be effective especially in late June to early July when peak flight of these moths usually appear.

There is a three week period from silking to harvest but there is only a two week period from when the silks appear and when they begin to dry. Since moths prefer juicy silks and shun those that have started to dry, insecticides are only needed the first two weeks of silking. There are a number of products that are effective against corn earworm. Homeowner products that have good efficacy and short intervals between spraying and harvest are arecyfluthrin in Bayer Vegetable & Garden Insect Spray and spinosad.

Though more time consuming, mineral or other light horticultural oils may also be used. The oil is placed inside the silk end of the ear with a medicine dropper after the silks brown. This will coat the earworms already present and likely suffocate them though some damage to the tip of the ear will likely have occurred. Contact me at the Wood County WVU Extension Office at 304-424-1960 with questions. Good Luck and Happy Gardening!

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