University of Vermont
Department of Plant and Soil Science

gmg logo   Summer News Articleline


Leonard Perry, UVM Horticulturist
and Charlie Nardozzi, Garden Consultant

August is generally a great month for gardeners—the weather is often pleasant, gardening chores are mostly done, weeds tend to not come back once cleaned from beds, and there is much to harvest or buy from local growers.  Harvesting basil, watching for hornworms and earworms, and pruning raspberries are some of the gardening activities for this month.

When harvesting basil, instead of just removing individual leaves, cut back whole stems. This will create a bushier plant that will produce more leaves and less flowers and scraggly growth. Pick basil in the morning for the best flavor. This is when the oil content in the leaves is highest.  Use the leaves to dry for seasoning later, or cook into pesto that you can freeze for later.   

Although the gardening season is drawing to a close, you will need to continue to keep an eye out for insect pests such as the squash bug and the striped cucumber beetle, which can feed on and damage young cucurbit fruits. A few new pests may arrive this time of year, including the corn earworm and the tomato hornworm.   

The hornworm is a three-inch long, green or brown caterpillar with eight curved stripes and a characteristic "horn" sticking up from its backside. It's a voracious eater, being partial to the leaves and fruit of tomatoes, eggplants, and peppers, and has been known to strip a plant virtually overnight if left uncontrolled. Its coloring provides good camouflage, so you will have to be diligent in your search for this pest. Hand pick and drown in soapy water or snip in half. Control the smaller worms with B.t. (Bacillus thuringiensis), a biological control. You may find hornworms that have been attacked by a tiny parasitic wasp, which attaches its white cocoons to the outside of the worms.   

Late July and August are prime picking times for sweet corn, but be prepared for the arrival of corn earworm, which migrates on storm fronts from the South. It is also called tomato fruitworm or cotton bollworm, depending on what crop it's eating.  Soon after arrival, the adult moths lay eggs on fresh corn silks, then the larvae feed in the tips of the ears. Corn varieties with poor husk cover of the ear tips are especially prone to damage.  Natural sprays to control corn earworms may include those with B.t., or Spinosad.  Even though these are natural products, make sure to follow all label directions and precautions.

In August, raspberry bushes, with the exception of the ever-bearing varieties, can be pruned after the harvest is over. Removing old canes that have just fruited can reduce the chance of getting cane diseases in new growth. However, do not fertilize plantings at this time, as that would encourage new growth to become succulent and more susceptible to winter injury. Fall is a good time to apply a thick layer of straw or leaf mulch around raspberries to suppress weeds next spring.

Other gardening activities for this month include sowing fall plantings of lettuce, peas and kale (make sure to keep them watered). You can also fertilize lawns and reseed bare spots if needed; take cuttings from tender perennials and annuals, such as geraniums and coleus, that you want to overwinter; plant a cover crop, if the garden is done producing for the season; and visit local fairs.  Consider entering your own flowers or produce in these fairs. 

(Charlie Nardozzi is a nationally known horticulturist, author, gardening consultant, and garden coach;   

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