Problems With Planting Zucchini with Summer Squash

When someone mentions summer squash, many people think of the yellow squash varieties, but zucchini is actually a member of the same family of vegetables, along with scallop/patty pan varieties. Summer squashes come in an interesting range of shapes, colors and flavors, but bringing together a number of different types can raise new issues and complicate existing issues in the garden.

Seeds as Carriers

Seeds can potentially be infected by viruses, fungus, mold and mildew, and carry these into your garden. Black rot fungus is just one of the possible unseen troublemakers that can hitch a ride on seeds. The more types of squash you plant, the greater the potential for this occurrence. The University of Minnesota Extension Service recommends securing seeds from a reputable dealer rather than saving seeds from areas of the garden, vegetables and plants that are affected by these issues.


Diseases, like pests, can spread among squashes. Choanephora rot usually affects summer squash and pumpkins. If one type of squash in a season becomes affected by the fungus, it can transfer to other squashes. Gardeners should choose disease-resistant varieties to decrease the potential for loss of multiple varieties from the infection of one.


Pests exacerbate disease issues, complicating attempts to treat the affected plants and adding an additional burden onto a struggling squash. For example, as beetles feed, they damage the structure of the plant. They can also carry bacteria and viruses, which enter the wounds in the foliage to begin an assault from the inside and take advantage of an already compromised plant.

Combined Damage

Gardeners should be aware that while some pests prefer one type of summer squash over another, once in the garden, pests may affect all of your summer squash varieties. For example, striped cucumber beetles like zucchini. Its presence in the garden may attract the bugs to your space. If the population of beetles grows or the food source is depleted, they may choose to feed on other squashes.


Those who hope to save seeds and plant a future crop from the harvest should be aware that zucchini and other summer squashes can cross-pollinate with gourds and pumpkins. If you expect to use seeds in a subsequent planting, the University of Illinois Extension Service recommends that you bag and pollinate fruits by hand to ensure seed purity.

Importance of Crop Rotation

Do not plant any zucchini or summer squash in the same location over consecutive years. The best practice is to select three separate areas of the garden for squash, and rotate from one station to the next with each planting. This lessens the chance that your current crop will be harmed by organisms that caused previous problems or that microbes will become established in the soil.

Keywords: summer squash troubleshooting, zucchini and squash, squash fungus

About this Author

Alice Moon is a freelance writer with more than 10 years' experience. She was chosen as a Smithsonian Institute intern, working for the National Zoo in Washington, D.C., and has traveled throughout Asia. Moon holds a Bachelor of Science in political science from Ball State University.