Problems Growing Zucchini

Zucchini, a type of summer squash, makes a terrific addition to the backyard vegetable garden. The plant produces a bounty of elongated fruit that can be eaten raw or cooked. Though it's relatively easy to care for, the zucchini plant has several specific growing needs that must be met, and can also occasionally fall victim to insect pests or diseases.

Poor Germination

Zucchini is a warm-season crop. Its seeds will not sprout if they're buried in cold soil. Gardeners should wait until the soil temperate is a minimum of 70 degrees Fahrenheit before sowing the zucchini seeds. Unlike many other types of vegetables, zucchini should not be started indoor since transplants fair poorly, according to the University of Minnesota.

Short Harvest Season

The zucchini plant is a voracious feeder. To sustain a long harvest season, gardeners should feed the plant with fertilizer. Insufficient soil nutrients will cause a drop in fruit production. The University of Minnesota recommends a 46-0-0 or 27-3-3 garden fertilizer. Apply the fertilizer according to its labeled instructions--potency varies by fertilizer brand--when the zucchini are seedlings, and again halfway through the harvest season.

Squash Bugs

You're not the only one who likes zucchini. Squash bugs (Anasa tristis) are a common insect pest that feeds on the plant and begin appearing in the spring. Infestations can last all year with the bugs sucking the juices out of the zucchini plant, causing widespread wilting and even death. Manually remove the bugs or, for heavy infestations, spray the zucchini plant with carbaryl or bifenthrin. The latter has a longer residual effect and is ideal for heavier infestations.

Melon Aphids

The melon aphid (Aphis gossypii) may look harmless, appearing as tiny black dots on the underside of the zucchini plant's foliage, but they are extremely destructive. Not only do the bugs feed off the plant and cause physical injury, but they also carry viral plant diseases like the Cucumber Mosaic Virus. Gardeners can release biological control agents like lacewings or lady beetles. Chemical controls include methomyl and endosulfan sprays. Endosulfan is the best insecticide for aphids, according to the University of Hawaii.

Powdery Mildew

During times of prolonged wet weather, gardeners may notice a white powdery coating on their zucchini plants. This is powdery mildew, caused by the Podosphaera xanthii fungus. Initial symptoms are only aesthetic, but untreated mildew growths can cause wilting, stunted zucchini plant growth and poor fruit development, according to the University of Minnesota. Standard fungicide, such as fixed copper spray, will resolve the issue. Reducing foliage moisture by only watering the vine at its base can also help dry out the fungus growths.

Keywords: zucchini growing problems, zucchini pests, zucchini diseases

About this Author

Josh Duvauchelle is an editor and journalist with more than 10 years' experience. His work has appeared in various magazines, including "Honolulu Magazine," which has more paid subscribers than any other magazine in Hawaii. He graduated with honors from Trinity Western University, holding a Bachelor of Arts in professional communications, and earned a certificate in applied leadership and public affairs from the Laurentian Leadership Centre.