Best Companion Plants for Vegetable Gardens in 2026

What Is Companion Planting?

Companion planting grows mutually beneficial plants together. Some combinations repel pests, improve soil nutrients, or provide shade for sensitive crops.

Top Companion Plant Combinations

Tomatoes + Basil + Marigolds

This classic trio works because basil repels tomato hornworms and improves flavor, while marigolds deter nematodes in the soil. Plant basil 6-8 inches from tomato stems and ring beds with marigolds.

Carrots + Onions

Onions mask the scent of carrots, deterring carrot fly. In return, carrots loosen soil for onion root development. Alternate rows for best results.

Beans + Corn + Squash (Three Sisters)

This Native American method stacks crops vertically: corn provides structure, beans fix nitrogen, and squash leaves shade soil to suppress weeds.

Plants to Keep Apart

• Tomatoes and brassicas (cabbage, broccoli): compete for nutrients
• Onions and beans: onion compounds inhibit bean growth
• Potatoes and tomatoes: both susceptible to blight

Seasonal Companion Planning

Start cool-season companions (peas + lettuce) in early spring. Switch to warm-season combos (tomatoes + basil) after last frost. Plan fall plantings with kale + herbs for extended harvest.