Why avoid planting cucumbers near tomatoes?
Written by
Michael Sullivan
Reviewed by
Prof. Charles Hartman, Ph.D.Planting cucumbers in proximity to tomatoes creates serious difficulties for both plants. Tomatoes attract hornworms, as well as blight diseases, which soon invade the cucumbers. Their luxuriant aftergrowth shades your cucumbers to some extent, and at the same time ravages the soil in search of plant food. In these ways, they diminish the yield and subject your cucumbers to a heavier attack of disease.
Pest Transfer
- Tomato hornworms migrate to cucumber plants
- Cucumber beetles attack both crops simultaneously
- Shared aphid populations spread rapidly
Disease Risks
- Blight spores transfer between plants via wind
- Powdery mildew spreads from tomatoes to cucumbers
- Shared fungal diseases reduce overall resistance
Resource Competition
- Tomato roots absorb nutrients cucumbers need
- Dense tomato foliage blocks essential sunlight
- Both plants require heavy watering creating conflict
Use protective spacing between these crops. Keep tomato and cucumber plants at least eight feet apart. Erect barriers with companion crops (like corn or sunflowers) that are taller than the vulnerable crops. This is an effective deterrent against the migration of pests and the development of transmitting agents for plant diseases.
Helpful partners greatly increase the health of cucumbers. The French marigold produces chemicals from its roots that will repel nematodes and beetles. The nasturtium lures aphids away from the cucumbers. Dill attracts predatory wasps that naturally manage hornworm populations without the use of pesticides.
Soil management Competition for nutrients is the other problem to be avoided. Make the beds separately, using compost appropriate to each plant. Cucumbers prefer a well-drained, nitrogen-rich soil, while tomatoes require phosphorus-rich soil. Move around to the same plot once a year, thereby breaking the life cycle of any pest or disease.
Microclimate adjustments serve to offset shading problems. Set out cucumbers in the fullest, open spaces available, preferably against a south-facing exposure. A reflective mulch will also help maximize light availability. These measures will help the cucumber plant meet its daily light requirement of 8 hours.
Read the full article: How to Grow Cucumbers Successfully
