June 30, 1993
Benlate and Conifer Diseases
You probably know that Benlate has been the subject of many claims from greenhouse growers about phytotoxicity on various crops. The fallout from this controversy included DuPont's virtually eliminating ornamental uses from the Benlate label. Contrary to what you may have heard, however, certain conifer diseases remain on the Benlate label. These include Diplodia tip blight (on Austrian, red, and Scots pine) and Swiss needlecast (on Douglas fir). The fungicide is labeled for brown spot needle blight, but ONLY on longleaf pine, which doesn't occur in Iowa.
Summer Gardening Hints
This spring and early summer have certainly been seasons for the record books. Abundant rains and cool temperatures have everyone wondering if this is the midwest or the pacific northwest. Listed below are some hints to help plants look and produce to their fullest potential.
Dividing Irises
While bearded irises are easy-to-grow, long- lived perennials, they need to be divided every 3 to 5 years. If not divided, the plants become overcrowded and flower production decreases. Crowded plants are also more prone to disease problems. The best time to dig, divide, and transplant irises is in July and August.
Consumer Reports Rates the Repellents
Insect repellents were researched and reviewed by Consumers Union and the results published in the July, 1993, issue of Consumer Reports magazine. Twenty-one different commercial products were tested, including aerosol and pump sprays, squeeze bottles or tubes, and wipe-on sticks and towelettes. Repellents were tested against two species of mosquitoes and against stable flies. Only mosquito repellency is summarized here.
Slugs in the Landscape
Slugs are usually not a problem in Iowa vegetable gardens and flower beds, although prolonged periods of wet weather like we have had for the past year may change our luck. Slugs are familiar pests because of the frequent write-ups they get in gardening publications from eastern U.S. where conditions for slugs are more favorable.