Question 1

Does companion planting really work?

Accepted Answer

Yes, companion planting is backed by both traditional gardening wisdom and scientific research. Marigolds have been proven to repel nematodes, basil can reduce aphid populations near tomatoes, and legumes genuinely fix nitrogen in soil that benefits neighboring plants. While not every folk pairing has strong evidence, the core principles of pest confusion, nutrient sharing, and beneficial insect attraction are well documented.

Question 2

What is the Three Sisters method?

Accepted Answer

The Three Sisters is a Native American companion planting technique that grows corn, beans, and squash together. Corn provides a natural trellis for beans to climb. Beans fix nitrogen in the soil, feeding the heavy-feeding corn and squash. Squash spreads along the ground, shading the soil to retain moisture and suppress weeds with its large leaves. Together, they form a self-sustaining system.

Question 3

What plants should never be planted together?

Accepted Answer

Some well-known bad pairings include tomatoes and fennel (fennel inhibits most nearby plants), beans and onions/garlic (alliums stunt legume growth), and potatoes and tomatoes (both are nightshades that share blight and pests). Dill and carrots should also be kept apart as they can cross-pollinate, and brassicas generally do poorly near strawberries.

Question 4

Do marigolds really help in the garden?

Accepted Answer

Marigolds are one of the most proven companion plants. French marigolds (Tagetes patula) release alpha-terthienyl from their roots, which kills root-knot nematodes in the soil. They also attract hoverflies and parasitic wasps that eat aphids, and their strong scent can confuse and deter whiteflies and cabbage moths. Plant them as borders around vegetable beds for the best effect.

Question 5

What about planting herbs with vegetables?

Accepted Answer

Herbs are some of the best companion plants. Basil planted near tomatoes may improve flavor and repel aphids and mosquitoes. Dill and fennel attract predatory insects like ladybugs and lacewings. Rosemary and sage deter cabbage moths and carrot flies. Chives planted near roses help prevent black spot. Most culinary herbs also attract pollinators when allowed to flower.

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