How to save Swiss chard from garden pests
Q. One of the crops I love to grow in my garden is Swiss chard; I love to stir fry it in olive oil with garlic and pine nuts. Although every year I battle some insect (I suspect earwigs, but I'm not sure) that loves to eat the young sprouts at ground level, in past years I've been able to keep them at bay by using insecticidal soap and diatomaceous earth. Not so this year I've replanted my Swiss chard crop twice, only to have both plantings decimated. Is it earwigs that are attacking the seedlings, or some other insect? Is there anything else I can do to keep the young seedlings from becoming some insects' meal? I'm considering using nonchemical based fly tape lining both sides of the rows with the tape as a barrier, but I don't know if sun/rain exposure will quickly diminish any effectiveness of the fly tape. HELP!
A. I'm sorry to hear about the loss of your Swiss chard due to hungry pests. Next time you plant-check very early in the morning and after dark to see if you might spot these critters. Without a description of their appearance, I suspect that your garden has been invaded by flea beetles. These are small (about 0.125 inch or 1 mm long) with a hard body and enlarged hind legs that allow them to jump like fleas when disturbed.
Flea beetles are most damaging when plants are young and just becoming established. Adult beetles feed on the leafy portion of the plant, chewing small holes and pits into the underside of leaves leaving a “shot hole” appearance. A small population of flea beetles can stunt or kill a stand of seedlings.
Our harsh winters don't seem to phase flea beetles as most appear to pass winter in the adult stage sheltering under plant debris left behind from the growing season. The adults emerge in spring and feed on the first weeds which pop up until crop plants become available. Consequently, they are frequent pests in seed beds and on new transplants.
Flea beetles have no natural predators or parasites to help control their populations. However, you may have some success in controlling these pests by using row cover materials over seedlings. These will provide a barrier to adult beetles if they are placed at or before emergence. The covers can be removed once the pest population subsides. You may also be able to control them by using white and yellow sticky traps which can be placed every 15 to 30 feet of row.
Another tack may be to use botanical pesticides such as neem, rotenone pyrethrin, or sabadilla. You may find that combining rotenone with insecticidal soap will be effective as well.
Since Swiss chard does well in cooler temperatures, you may be able to try another planting before frost arrives. But if you decide to wait until next year, just be sure to remove any debris and destroy any potential refuge sites as these are favorite places for adult beetles to overwinter. Good luck!
Q. How do you test your soil and why is it important to do so?
A. The results of a test can provide valuable information to make decisions concerning: how to apply soil amendments to improve soil quality, nutrients that are lacking or in excess in the soil, how to adjust the soil pH to promote growth of acid-loving plants such as rhododendrons, or the amount of lead and other metals in the soil.
Before you take a sample of soil, size up the area to be tested for differences in soil characteristics such as color, texture and drainage. If these features are uniform throughout your property or test area, a single composite sample of soil will be sufficient. However if there is a variation in soil types, or if there are disturbed areas where fill soil has been added (such as from a crawlspace or basement), separate samples should be taken and treated as individual samples. You can take samples any time of the year. However, late summer or fall is best before soil temperatures drop below 50 degrees.
The following are basic steps for collecting samples (always follow the specific instructions from the company that you are sending the soil samples to):
• Get a clean bucket and trowel or shovel which is neither rusted or made of galvanized metal, which could skew your results.
• After scraping mulch and litter from the soil surface, dig out a wedge of soil 6 to 8 inches deep and place in your bucket.
• Repeat this procedure in at least eight well-scattered spots, placing each sample in the bucket with those previously taken.
• Thoroughly mix the slices of soil together to make one composite sample.
• Use about one pint of the soil mix as a sample. Discard the rest.
• Pack the sample (thoroughly air dried) in a plastic bag and enclose it in a sturdy box, carton or can. Flimsy containers may break during shipping. Label each sample with your name and address. If sending more than one sample, label each sample with a number indicating where it was taken (flower garden, vegetable garden, lawn or shrub border).
Because the University of Illinois Extension in Cook County does not maintain its own soil testing laboratory, you must send your samples to a commercial laboratory for testing. However, a list of laboratories that will test soil samples for homeowners is available form local Extension offices.
• Provided by Mary Boldan, Mary Moisand and Donna Siemro, University of Illinois Extension Master Gardeners. Send questions to Ask a Master Gardener, c/o Friendship Park Conservatory, 395 W. Algonquin Road, Des Plaines, IL 60016, (847) 298-3502 or via e-mail to cookcountymg.com@gmail.com.