Gardeners Checklist: Here Is What To Do the Week of July 21

* Don’t water lawns unless you can keep it up on a weekly basis. A “when I think about it” approach to watering lawns can do more harm to grass than letting it go dormant. 

* Don’t let cabbage worms get out of hand; they’ll turn cabbage into coleslaw. I like coleslaw, but I’d rather make my own. Control cabbage worms with applications of Dipel, Thuricide, or similar products whose primary ingredient is the bacterial spores of Bacillus thuringiensis. Use these same products to control cabbage worms on broccoli, Brussels sprouts, cauliflower, collards, kale, and kohlrabi.

* Leave a few leaves at the base of the plants intact when harvesting heads of cabbage, including Chinese or Napa cabbage. New shoots should arise from the base of the plant, much the same as side buds develop on broccoli after the main head has been harvested. Since the plants have a strong root system, these shoots will develop rapidly. To get a larger head, trim off all but one of these new shoots.  However, if you let several of the shoots remain, the plant will still produce new but smaller heads.

* Check for potatoes that may have come to the soil surface. Mound soil or place straw mulch over the exposed spuds. Potatoes exposed to sunlight turn green due to the formation of chlorophyll. At the same time, they produce a toxin called solanine, which gives green potatoes a bitter flavor. Eating too many green potatoes may also cause nausea, headaches, diarrhea, and a host of neurological problems.

* Remove any overgrown squash from zucchini and other summer squash. Otherwise, the plants will stop flowering and stop producing more squash. 

* Cut stems of oregano and basil for drying just as flower buds appear. Even if the stems won’t be dried, cut back the flower shoots anyway to keep the plants producing more leaves.

* Watch out for wasp nests when working or playing outdoors. They can occur in the most unexpected places, as many of us have found out recently. If wasps pose a danger to you or to visitors (many people are allergic to the wasp and bee stings), wait until dark and then spray the nests with some type of wasp and hornet control product.

* Groom plants in hanging baskets. Remove faded flowers daily and trim back shoots that have become ungainly or leggy. Since soil in hanging baskets dries faster than soil in patio pots, check the soil moisture level a couple of times each day. Because of frequent watering, plants in hanging baskets also need frequent doses of liquid fertilizer.

* Keep houseplants away from the cold drafts from air-conditioners. The cold air may cause some plants to wilt or drop their leaves.

*

It’s time for a mid-season tune-up of the lawn mower. Just like this old gardener, the old mower has been working overtime. A little preventative medicine….er, maintenance will keep it going through the rest of the summer. The instruction manual for the mower will provide details for proper maintenance. For those of us with a penchant for misplacing such important pieces of literature, here’s a checklist for some basic mower maintenance: tighten all nuts and bolts; clean dirty parts especially engine parts such as the cooling fins; check the gap and clean gunk (technical term for carbon or sludge deposits) from the sparkplug electrode; clean the air filter; change the oil; sharpen the mower blade (be sure to disconnect the spark plug cable before working on the mower deck); and scrape caked on grass from the mower deck.   

Ron Kujawski began gardening at an early age on his family's onion farm in upstate New York. Although now retired, he spent most of his career teaching at the UMass Extension Service. He serves on Berkshire Botanical Garden’s Horticulture Advisory Committee. His book, Week-by-Week Vegetable Gardener’s Handbook, is available here.