Zucchini Cucurbita pepo is a small cucumber-shaped vegetable that is typically dark green in color. It is a member of the cucurbits family that includes other vegetables such as summer squash, pumpkins, gourds, watermelons and muskmelons. The features of this family are obvious: They grow on vines with divided leaves set on every other side of the stem; their fruits are large with hard outside casings.
Zucchini plants are started from seeds. The seeds are usually planted a ½ inch deep around an 8-inch deep mound of soil with an indented center. Once seedlings emerge, if numerous in number, they should be thinned out to three per mound. The seedlings require water but not directly. The water should go into the mound up to plant level. The plants require fertilizer when the fruit starts forming. The fertilizer is put in the soil and then watered right away to soak in the fertilizer. These plants do require care and protection from a certain group of insects that specifically affects these vegetables.
This bug sucks the sap from the leaves and causes leave wilt. They can also feed right on the fruit itself and cause severe damage. The adults are dark gray and about 5/8-inch long. They can overwinter in protected areas, and lay eggs on the underside of leaves in the spring.
Cultural control consists of plant rotation and sanitation. Do not leave plant debris on the ground over winter. Another control method is destroying the eggs from the underside of the leaves. Finally, squash bugs like shelter, so remove any possible shelter to help reduce the number of bugs.
Squash Vine Borer
The adult is a colorful moth about 5/8-inch long. The adults can be mistaken for wasps in flight. Their larvae bore into the stem, hollowing out the vines. This will cause plant wilt or rot and death. The first indication is a sudden wilting of a long runner or plant; partial or complete loss can occur.
A non-chemical control method involves covering the plants with a row cover until blooming begins. This prevents the moth from laying eggs. The use of chemical treatments are also a possibility if other methods are ineffective. It is always recommended to contact the local County Extension office or garden center before using any chemical products.
Striped Cucumber Beetle
Striped cucumber beetle (SCB) is about a quarter-inch long with black and yellow stripes. The adults survive winter and live until August. They feed on an entire plant in the cucurbit family. The adult beetles lay their eggs at the base of the plant and the larvae feed on the roots. The new generation emerges in July. In addition to the direct harm they do plants, they also carry an organism that causes bacterial wilt. Zucchinis are one of the more susceptible plants to this disease.
Cultural control for the SCB is similar to that of the squash bug. Plant rotation and sanitation are important. Change the planting sites each year and put down fresh soil to escape previous infestation. Also, use sticky cups or tape to trap the beetles and decrease infestation. Older plants that are bought or transplanted from other areas are more tolerant to the beetle when it arrives, so this is an alternative to seeding directly. Organic sprays also can eliminate the SCB; these include Kaolin clay (Surround) or Pyrethrum.
It is important to harvest the fruit as soon as they are the desired size. If they grow too big, they will have overly large seeds, hard skins and fibrous, watery flesh. If large fruits are left on the vine, the plant will decline. Vines send out new roots, so take care when harvesting not to disturb the new growth.