August Gardening Tips for the Midwest

High summer brings delicious vegetable harvests and outstanding flower power from annuals and perennials.

The Midwest Vegetable Garden

Make the most of your tomato and pepper crops with these growing and harvesting tips.


Rosalita tomato

The fruits will continue to ripen after picking, but large types develop peak sweetness when left to ripen on the vine. However, many varieties of cherry tomatoes tend to split as they ripen, so pick them as soon as they show color.

Continue to tie up vines as you pick tomatoes; it makes harvesting easier. Remove lower leaves that are crispy or yellowing.

Avoid heavy irrigation for fruit in final ripening stages: An abundant supply of water dilutes tomato flavor and makes the fruits more susceptible to cracking.

Don't worry if your tomatoes stop producing fruit when it gets especially hot; fruits don't typically set well when temperatures exceed 90 degrees F.


Keystone Giant Bell Pepper

Pepper plants frequently develop black spots on stems where leaves or fruit attach. This isn't a disease; it's normal coloration.

Pick peppers at any color stage: green, red, or a shade in between. But note that the sweetness increases the longer sweet peppers remain on plants and heat increases as hot peppers remain on plants. Learn which flavor stage your family prefers, and pick fruits accordingly.

Wear gloves when handling hot peppers. Always be sure to wash your hands before touching mouth, eyes, nose, or using a bathroom -- even if you have been wearing gloves. Capsaicin, the compound responsible for a pepper's heat, can transfer to fabric and retain its ability to burn. Toss linens used when processing hot peppers into the laundry.

Use milk or yogurt to counteract the burn of a hot pepper when it's in your mouth.

Peppers often drop blooms when temperatures soar above 90 degrees F. Keeping soil consistently moist during flowering also helps prevent blossom drop.

Flavorful Herbs

Basil, Tomato, Cabbage, Chard, Calendula

Pick herbs frequently for prolonged harvests. It's best to harvest herbs before flowering occurs, because bloom formation changes leaf flavor.

Try one of several methods to preserve herbs and enjoy summer-fresh flavors year-round:

1: Dry individual leaves in a basket or on old screens. To preserve maximum flavor, don't chop leaves until just before you use them.

2: Bundle stems together and hang them upside down.

3: Chop herbs and freeze them in water in ice cube trays. Cubes make a tasty addition to soups, sauces, and stews.

4: Use a food processor to blend finely chopped herbs with oil. Freeze the resulting slurry in ice cube trays.

Easy-to-grow herbs.

Savor Summer Color in the Midwest


Stock your patio and garden with plants that continue to flower as the temperature soars.

Annuals: Heat-lovers include verbena, Diamond Frost Euphorbia, Portulaca, and zinnia.

Tropicals: Mandevilla, brugmansia, hibiscus, and glory bower thrive on heat. In containers, increase flower number by feeding plants liquid bloom-booster fertilizer every 10-14 days.

Perennials: Black-eyed susan, coneflower, Shasta daisy, and bee balm all stage a stunning summer show.

Test Garden Tip: Deadheading is the process of removing faded flowers. This action encourages the formation of future blooms.

  • Container plantings can need watering as often as twice a day in hot, windy weather.

Mulch Matters -- You may need to replenish mulches, especially those that break down quickly, such as straw or grass clippings. Mulches should be 1-3 inches.

Mulch Matters

Whack Your Weeds -- Time weeding for after a good rain. Weeds come out easier and with more of the root.

Deadheading 101 -- Keep deadheading! For the most flowers and tidiest garden, deadhead daily.

Deadheading 101

  • Keep an eye out for aphids and spider mites. Treat with insecticidal soap. Spider mites, which also thrive in dry weather, can be treated with pyrethrums, an extract from mums.

Plan Ahead: Start New Plants

Take cuttings now of plants you want to overwinter indoors as houseplants. Choices might include coleus, scented geranium, fuchsia, or wax begonia. Take 3- to 4-inch cuttings of green stem tissue and remove lower leaves. Dip cuttings in rooting hormone before sticking in soil. Keep soil moist until roots have formed.

How can you tell if roots have formed? Pull gently on stems. You should feel some resistance if roots have formed. Another clue to successful rooting is new leaf formation.

Think Spring


Now's the time to order peony roots so you have them for planting about a month before your area's average first frost date. Aim to have peonies planted before the first killing frost. Now is also the ideal time to order bulbs for next year's spring show. Try different bloomers, such as Siberian squill, giant allium, fritillary, or anemone.

Garden Maintenance


Mow Higher. If you haven't raised the mower height all season, do so now. Taller grass withstands drought better and shades soil, which slows water evaporation.

Water Compost. Keep your compost pile moist. Do not add weeds that have set seeds to the pile. Also avoid composting diseased plants.

Keep it Clean. Remove annuals that have faded and look bad. Spread mulch over patches of bare soil to keep weeds from sprouting.

Leave Roses. Don't cut faded rose blooms. If you stop deadheading, plants may set hips for winter interest. It's also time to stop fertilizing roses for the growing season. If you feed roses now, you risk pushing new growth that will die when the killing frost arrives.

Enjoy Evergreens. Don't prune your evergreens now: Pruning will cause new growth to emerge that won't have time to harden off before cold weather arrives.

Deadhead. Cut garden phlox flowers after they fade. If plants set seed, seedlings won't come true to parents.


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