Gardeners Checklist: Here Is What to Do on the Week of Aug. 28

By Ron Kujawski

• Make time to study the plants in your perennial border. Look for plants that are being crowded or are crowding other plants, those looking ratty due to pest and disease, and those that just don’t offer much in terms of flowers or foliage. Make a note on your garden calendar to divide the overgrown ones next spring. The others may be best treated by simply ripping them out of the garden. There are so many great plants on the market, why fuss over those that are prone to pests and disease problems or that offer little ornamental value.

• Check mums for leaf tiers. Leaf tiers are caterpillars that exude silken threads to tie together the leaves upon which they are feeding. Leaf tiers can be found on a wide variety of plants throughout the growing season, and mums are a favorite host at this time of year. Normally I don’t worry much about this insect pest, but with mums about to begin their floral display, I try to preserve the attractiveness of the plants by applying a natural pyrethrum-based insecticide to control the leaf tiers.

• Use a slow-release or organic fertilizer to feed the lawn this week. When temperatures cool, grass will begin to grow with some vigor, especially if given a boost from a fertilizer application.  If you make just one application of fertilizer to the lawn, this is the time to do it. Grass is recovering from summer stress; new root growth is beginning; and grass must be restored to good health if it is to survive winter.

• Take cuttings from fuchsia, wax begonia, coleus, African daisy (Osteospermum), geraniums, lavender, rosemary, and other garden plants for growing indoors this winter. After dipping cuttings in a rooting solution or powder, stick them in pots or flats of vermiculite, perlite or clean sand for rooting. Once rooted, pot up the plants and place them on a sunny windowsill or under fluorescent lights.  In late winter, cuttings can be taken from these houseplants to make plants for the summer garden.

Knowing when to harvest vegetables is not usually a tough decision. Many vegetables, such as summer squash, cucumbers, eggplant, leafy greens, and green beans, are best picked before they are fully mature. Such is not the case for melons and for winter squash, including pumpkins. They must reach full maturity if they are to taste any good and hold up in winter storage. With melons, look for the ground spot (the side of the melon in contact with the ground) to turn from white to cream or yellow before harvesting.  With pumpkins, harvest when the fruit has developed a deep, solid orange color and the rind is hard. With some winter squash, judging color can be difficult. With these I rely on the thumbnail test. When the rind is hard enough to resist penetration with my thumbnail, they’re ready to harvest. Just don’t use this test too often since it may create wounds that will shorten the storage life of the pumpkins and squash.

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.