Gardeners Checklist: Here Is What to Do on the Week of July 15

By Ron Kujawski

* Weed, water, and mulch. That’s the order of the day in the vegetable and flower garden. 

* Apply a deer repellent to hostas. Deer love the succulent leaves of hosta. Typically, they eat the leaf blades but leave the leaf stems intact. Reapply the repellent at weekly intervals.

* Thin crowded strawberry beds by removing all but the sturdiest-looking plants. Afterwards, remove any weeds and apply cottonseed meal or similar fertilizer at a rate of about two to three pounds per hundred square feet of bed.

* Check potato and eggplant for Colorado potato beetles. They may be in the larval stage. cPotato beetle larvae are hunch-backed and rusty red or pale red in color. insecticide containing spinosad, neem, or the bacterium Bacillus thuringiensis, var. tenebrionis are safe materials to use for control. cHand-picking the larvae and adult beetles is another option.

* Sow seeds of biennials, including Canterbury bells, foxglove, digitalis, sweet William, Siberian wallflower, and Iceland poppies, for a display of flowers next year. Keep the seedlings well watered and shaded on hot, sunny days.

* Look for yellowing, bronzing, stippling or webbing on leaves of vegetables, flowers, and woody plants, including conifers.c These are symptoms of spider mite infestation. Spider mites, which thrive in hot, dry weather, are very tiny; you may need a magnifying glass to see them. In many cases, natural predators keep spider mite populations in check. However, when populations rapidly increase, as often happens during the summer, it may be necessary to apply a miticide. One option is to apply a summer oil, such as Sun Spray Ultra Fine Oil, at the rate of 1 1/2%. Be sure to read and follow all the instructions and safety precautions found on the pesticide label before using any pesticide.

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Sneak a peek at your neighbors’ gardens to see what perennials are holding up to the hot and dry weather. Or, visit some public gardens - though it’s more fun to sneak into neighbors’ gardens. Make a shopping list of the long-blooming plants that are looking great despite the sultry weather. Some examples are Achillea, Agastache Echinacea, Rudbeckia, Monarda, and Coreopsis. It’s not too late to buy and plant container-grown perennials. Just remember that these plants don’t instantly become drought-tolerant. They will still need plenty of moisture to get their roots well established. Also, any perennials planted now should be shaded for several days and anytime thereafter when they show signs of wilting. 

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.