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It’s pickling time. And it’s also the time when cucumber wilt shows up in the garden. It is caused by a bacterial wilt that is one of the most common diseases that infect cucurbits (the cucumber family). Cucumber wilt is most severe in cucumbers, but can also infect muskmelons, squash, pumpkins and gourds.

In cucumbers, the first symptom of wilt is a distinct bronzing of individual leaves, followed by wilting of adjacent leaves, and then the collapse of the entire plant. You cannot cure plants that have bacterial wilt; they must be removed from the garden and destroyed.

To diagnose bacterial wilt, cut a wilting stem and squeeze the cut end lightly. Place the two cut ends together, then slowly pull them apart. If a string of sticky ooze develops between the two ends, the cause is likely bacterial wilt. If you still aren’t certain, place the cut end of an affected stem in a glass of water and wait for ten minutes. If the plant is infected by the bacterial wilt pathogen, milky strands of ooze will flow from the cut end in the water.

Both of these diagnostic techniques will work better for cucumbers than for other cucurbits.

Bacterial wilt is primarily spread by two insects; the spotted cucumber beetle and the striped cucumber beetle. They transmit the disease when they nibble on your plants. To manage the disease next year, plant resistant varieties to minimize the incidence and severity of the disease, and try to prevent these beetles from feeding on your plants. Bacterial wilt resistance is available in a few cucumber cultivars, including County Fair 83.

Insecticide application is not recommended since you would need to spray frequently to control these beetles, and the insecticide can also kill those insects needed for pollination. A more effective and environmentally friendly approach is to cover the plants with floating row covers, which will protect the plants until they flower. However, once flowers appear, the row cover must be removed to allow insects access to the flowers for pollination and fruit formation. Floating row covers are available in catalogs and at garden centers.

Another problem for the gardener of cucurbits is the squash vine borer. This pest can damage zucchini, winter and summer squash, and pumpkins.

Squash vines that are infested with the borer often collapse and die. The adult squash vine borer is a type of moth, with a slender, wasp-like body, with noticeable orange areas on the abdomen and clear wings. Adults emerge from the ground where they have over wintered in their cocoons, and begin to emerge in late June and early July. The female moths deposit pinhead-sized brown eggs along the lower part of the squash stem, usually within a few inches of the soil. When the eggs hatch, the worm-like larvae burrow directly into the squash stem and proceed to feed and grow within that stem. Their feeding ruins the plant’s water transportation system, so that one of the first symptoms of borer damage is leaf wilting. Infected plants will often die from the effects of the squash borer larvae.

The floating row cover approach used against cucumber beetles can be used to protect against this pest also. Since male and female squash blossoms grow separately, they require pollination for proper fruit set, so removal of the row cover when flowers begin to appear is very important. Winter squash and pumpkins must set early so they have time to mature before frost. The borer damage can be prevented if you very carefully scrape the eggs off the stem, but if only one is missed, you could still end up with a dead plant.

If you wish to use pesticides, apply one labeled for squash vine borers such as Carbaryl (Sevin). Very carefully dust or spray the lower stems with pesticides when you first see the adult borer moth. Sevin is very toxic to bees, so avoid dusting or spraying in, on, or near the squash flowers.

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Master Gardeners will be available to answer your questions at the Almelund Threshing Show, Aug. 14, 15 and 16.

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There are also three remote drop off sites for samples in the county: Mannions Greenhouse and Floral in Rush City, North Branch Floral and Federated Coop (Cenex) on Highway 8 in Chisago City. There will not be a Master Gardener on site, but these businesses have agreed to hold the samples for pickup.

There will be Master Gardeners on site to answer your questions Thursday evenings from 6-8 p.m., at the Chisago County Hazardous Waste facility, in North Branch.

The Lindstrom Farmers’ Market is now open. There is a Master Gardener there from 8 a.m.-noon every Saturday.

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Other ways to access information: www.extension.umn.edu/county/chisago. Check out the “Hot Topics” box in the middle of the page for current Chisago County Master Gardener news and events.

You can also click on “Ask a Master Gardener” next to the cute little flower on the right hand side of the page. Here you can search 1000s of answers from Master Gardeners around the state. If you don’t find your answer, you can submit a question online or search for University publications.

Bell Museum

For information about snakes, skunks, raccoons or other wildlife around your yard, call the wildlife information line at (612) 624-1374 or www.bellmuseum.org.

Or, call the Master Gardener voice mail (651-237-3080), leave a message and a Master Gardener will call you back within a couple of days.

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