Growing butterfly milkweed, harvesting garden produce often, and keeping container plantings watered are some of the gardening activities for this month.
Butterfly weed (Asclepias tuberosa) is not a weed at all (a plant out of place that you don’t want in your garden). Better common names are butterfly or orange milkweed, as it is in the milkweed family, has orange flowers in mid to late summer, and attracts butterflies. Other benefits are that it is hardy, low maintenance, good in rain gardens as well as drought and dry soils, tolerates deer, and the leaves feed monarch butterfly larvae. For all these reasons it was named the Perennial Plant of the Year for 2017.
Harvest tomatoes, zucchini, beans, and other fruiting crops frequently to encourage continued production. Remove any fruits that have gone by unless you’re in competition for the biggest zucchini! You don’t want the plant to produce mature seeds because that will signal that it’s time to slow down fruit production.
Check container-grown plants frequently, and water as necessary to keep the soil moist. Soil can dry out very quickly, especially in small containers and those made of clay. Hanging baskets, especially those lined with sphagnum moss or coir (the rough tan material made of coconut husk fibers), also dry out daily when plants are mature. If you bought a basket already planted or didn’t incorporate water absorbing gels at planting, scratch some in the surface now. You can find these at many complete garden stores. They hold much water, releasing it to the plants over time.
During periods of frequent rainfall, nutrients are washed out of the soil of container plants. Many of the newer annual flowers are raised, and bred, to need high fertility. Give them a dose of liquid fertilizer to keep them producing flowers for the rest of the season. Add a dilute fish emulsion- or seaweed-based fertilizer to the water each time you water, or a synthetic liquid or slow-release fertilizer according to label directions.
Check tomato plants for large, green-striped horned caterpillars. A few can cause lots of damage, so hand pick and destroy them when found. Spray the organic pesticide B.t. (Bacillus thuringiensis) to control large infestations.
Protect your squash vines from the squash vine borer. These clear-winged moths lay their eggs on the stems and the hatching larvae bore into the vines, causing the plant to wilt and possibly die. Apply the organic pesticide B.t. every 3 or 4 days during July and early August to kill hatching larvae before they enter the stems. A thin layer of wood ashes or moth flakes scattered around plants may discourage egg laying.
If these don’t work on the squash vine borer, slit the vine stem where it is wilting and back until you find the feeding grub. Remove and destroy it, then bury the end of the vine so that hopefully it will root and resume growth.
Strawberries, raspberries, blackberries, cherries, and other fresh, very perishable fruit should be kept refrigerated and not washed until serving time. Green vegetables, however, such as broccoli, peas, and beans, as well as beets and carrots, should be washed before storing in the refrigerator.
Leonard Perry, UVM Horticulturist
and Charlie Nardozzi, Garden Consultant
Charlie Nardozzi is a nationally known horticulturist, author, gardening consultant, and garden coach (CharlieNardozzi.com). Distribution of this release is made possible by University of Vermont and Green Works—the Vermont Nursery and Landscape Association.