William Hogan | 4/14/2011 9:28:30 PM
Based on the number of calls that I receive, cucumbers have become as popular a garden plant as tomatoes. They also rank second in overall problems. This is probably due to the vast number of cucumbers grown (more plants, more problem plants).
Cucumbers can be planted now throughout the growing season, but be aware that those planted from May onward yield less than the early plantings. They may be direct seeded or transplanted. Space individual seeds or transplants about twelve inches apart. If you want to plant in hills, plant four seeds to the hill, 24 inches apart. When the plants become established, thin to two plants per hill. If you crowd them, they compete with each other. If you don’t have a soil test on which to base fertilization, about twelve pounds of 13-13-13 per 100 foot of row is usually sufficient for our soils. In addition to space between plants, cucumbers need space to produce vines. Cucumber yields can be doubled by using a trellis. To get the vines to climb the trellis, you might have to train the first vines to climb the trellis.
There are several good varieties of cucumbers. Most of us are going to plant what the garden store has available that day. That’s OK. These usually will work. Recommended varieties for slicing or fresh cucumbers include: Taledega, Dasher II, Fanfare, Diva, General Lee, Speedway, Poinsett 76, Slice More, Thunder, Indy, Intimidator, Sweet Slice and Sweet Success. (Based on some of these names, cucumber breeders must be car racing fans.) For pickling: Calypso, Faucipak and Jackson are recommended. If you have had success with a variety not listed, stick with what works for you.
Now for the potential problems:
1) Seedling disease is common in young cucumber plants. It seems to be more common in direct-seeded plants than transplants. These seedling diseases are caused by fungi that live in the soil. They attack the roots of the seedling plant and kill them. The young plant will wilt and rot off at the soil line. If you can’t find seed that has been treated with a fungicide, your only solution is to replant. In the later season, as the soil warms and dries, the plant often grows faster than the fungus can kill it. Older, more mature plants are less susceptible to soil-borne fungi.
2) Plants with vines and blooms but no fruit are common in the early season. Or, the first fruit fall off the plant before they reach a usable size. This is usually due to poor pollination. Cucumbers have male and female blooms. The male bloom produces the pollen. Male flowers are the first to be set, usually a week or ten days before the female flowers. The female flower has the small cucumber at its base. The pollen must be carried to the female bloom for fertilization to produce the fruit. Bees are our best transport system for this. Therefore, encourage bees and other nectar feeding insects to visit your cucumber patch. Don’t use insecticides during the morning or early afternoon. This kills or at least discourages bees from visiting your cucumber vines. If necessary, apply insecticides in the late afternoon, when bee activity is at a minimum. To further complicate this issue, many newer cucumber varieties have been bred to have a much larger percentage of female flowers. This is good, for if they receive pollen, you get more fruit. However, it does make good pollination more critical than ever. To encourage pollination, be sure to plant a few plants of a variety that have plenty of male flowers. These include General Lee, Thunder, Poinsett 76, Slice Master Select or Jackson.
3) Reports of leaf spots on the vines are the most common call that I receive. These are caused by yet another fungus that attacks the leaves of the cucumber. Yellow or white spots appear on the bottom side of the leaf, the leaf wilts and falls off. The vine will often die when enough leaves fall. This disease is called Anthracnose. It is a major problem that can only be prevented by using a recommended fungicide. As soon as the vines begin to run, make weekly applications of a fungicide containing Chlorothalonil (there are several available in the garden stores.) You must start these applications early and continue on a regular weekly schedule to prevent this disease.
Pest Updates -- Weeds and Caterpillars
Two weeks ago I warned that it was the time of year for tree feeding caterpillars to begin appearing. Well, they certainly have been present in numbers as large as I can remember. The forest tent caterpillar is the most common, but the stinging caterpillars have also been a problem in the area east of Jefferson Davis Parish (from Lafayette to New Orleans). Use a recommended insecticide before they strip your trees. They’re seasonal and the large populations will only last for a few weeks.
Cool season lawn weeds have matured and are going dormant by now. Troublesome warm-season lawn weeds are just beginning to become evident. Dollarweed and Virginia buttonweed are two of the most troublesome warm-season weeds in our lawns. An application of a recommended herbicide in early spring is more effective than waiting until the weeds are larger and more mature. The post emergence herbicides, Trimec, Weed-B-Gon and Weed-Free-Zone, give fair to good control of these weeds. Dollarweed is also controlled by the herbicide, Image. Image requires a little time to produce symptoms on the dollarweed, but is effective. All these herbicides produce better results in warm weather (60 degrees F or warmer). When applying any pesticide, follow all label directions and restrictions. Don’t apply herbicides on a windy day. Be sure the herbicide you choose is labeled for use on your species of lawn grass. You may experience some temporary browning of lawn grass if it is young and tender at the time of application.
Proper mowing, fertilization and irrigation are also a part of weed management. These don’t kill the weeds, but they make the lawn grass healthier, more vigorous and better able to compete with any weeds present.