Does companion planting really work?

Many combinations are well-documented: alliums deter carrot fly, marigolds repel nematodes, and the Three Sisters (corn, beans, squash) is a proven system used for centuries. At worst it increases biodiversity.

How close should companion plants be?

Close enough to benefit each other but not competing for light, water or nutrients. Generally 15-30 cm between different species, following each crop recommended spacing.

What is the Three Sisters planting method?

An ancient method: sweetcorn provides support for climbing beans, beans fix nitrogen in the soil, and squash shades the ground reducing weeds. Plant in blocks rather than rows for best results.

GardenCalcs

Companion Planting Layout Calculator

Calculate companion planting layout and spacing for common vegetable combos.

Main CropChoose the primary crop for your bed

Bed Length

Length of your planting bed in metres

Bed Width

Width of your planting bed in metres

How We Calculate This

Select your main crop and enter your bed dimensions. The calculator looks up recommended companions and avoids, then estimates plant counts based on each species optimal spacing.

Rows are calculated across the bed width, plants per row along the bed length. An edge buffer keeps plants away from bed edges for access and airflow.

Frequently Asked Questions

Last updated: March 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.