Strawberry bed renewal, chiggers
Next year’s strawberry crop will be affected by what you do to this year’s strawberry bed. The sooner after harvest the patch is cleaned up, fertilized and irrigated, if possible, the better the chance of getting a good crop next year.
One of the main goals in renovation is to provide a high level of sunlight to plant leaves so they can manufacture the food the plant needs. If leaves have disease spots, remove all the leaves in the bed. Removing these diseased leaves and weeds will cause new, non-diseased leaves to develop and remove competition from weedy plants.
Hedge shears or even a mower can be used. Be sure the mower blade is high enough to avoid the strawberry crowns.
It is also important to reduce the number of strawberry plants so they do not compete for light, moisture and nutrients. If you have a small bed, you can hoe out or pull some plants so they are spaced about four to six inches apart. On large beds, adjust a rototiller so you can till between the rows, and cut each row back to about 10 inches wide.
The next step is to fertilize the plants with about 3/4 to one pound (three to four cups) of a complete fertilizer such as 13-13-13 (nitrogen, phosphorus and potassium) or an equivalent on each 25 feet of row.
If a soil test shows adequate levels of phosphorus and potassium, use 3/4 pound (1-1/2 cups) of a 16-0-0 (nitrate of soda) fertilizer per 25 feet of row instead.
If nitrate of soda is unavailable, use the lawn fertilizer that contains about 30 percent nitrogen such as a 30-0-3, 28-0-3 or something similar. Make sure the lawn fertilizer does not contain a weed killer or preventer. These fertilizers should be used at the rate of 3/4 cup per 25 feet of row.
The next step is to irrigate or wash the fertilizer into the soil and provide moisture for the rapid growth of the strawberry plants. When the soil is dry, apply about one inch of water. A garden sprinkler can do a good job applying the water.
Controlling weeds and watering throughout the summer are important so plants are vigorous when fruit buds begin to develop in September and October.
Chiggers are mites, not insects. And like all mites, the adults have eight legs. However, the larva only has six legs.
Though the bright red female adult is tiny (about 1/20th of an inch) the larva is much smaller (about 1/150th of an inch). Only the larvae are parasitic and attack animals. The larva injects digestive juices into the skin, which causes a rapid swelling In the center of the swelling is a “feeding tube” from which the chigger sucks out liquefied skin cells. Feeding usually continues for two to four days.
Protection from chiggers takes two approaches. The use of a repellent can discourage chiggers from attacking. The most effective repellents are Deet and permethrin. Both are applied to clothing.
The second approach seeks to reduce chigger populations. Keeping the lawn mowed regularly can help, but large populations may require the use of an acaricide. Effective products include bifenthrin (Talstar, Hi-Yield Bug Blaster II, Hi-Yield Bug Blaster Bifenthrin and Ortho Lawn Insect Killer Granules), cyfluthrin (Tempo 20, Bayer Vegetable and Garden Insect Spray) and carbaryl (Sevin).
For more information, see the K- State Research and Extension publication titled, “Chiggers” at http://www.ksre.ksu.edu/bookstore/pubs/MF2107.pdf.