Companion Planting Chart: The Complete Guide to What to Plant Together
Quick Answer
Companion planting pairs vegetables that help each other grow. The classic "Three Sisters" (corn, beans, squash) is the most famous example. Tomatoes love basil. Carrots and onions protect each other from pests. Avoid planting fennel near anything—it inhibits most vegetables.
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What Is Companion Planting?
Companion planting is the practice of growing certain plants near each other for mutual benefit. Benefits include:
- Pest control — Strong-scented herbs repel insects
- Pollination — Flowers attract bees to your vegetables
- Space efficiency — Tall plants shade cool-weather crops
- Soil health — Legumes fix nitrogen for heavy feeders
Companion Planting Chart
Tomatoes
| Good Companions | Bad Companions |
|---|---|
| Basil, carrots, parsley | Brassicas (cabbage, broccoli) |
| Marigolds, nasturtiums | Fennel |
| Onions, garlic | Corn |
| Peppers | Potatoes |
Why it works: Basil repels aphids and tomato hornworms. Marigolds deter nematodes.
Peppers
| Good Companions | Bad Companions |
|---|---|
| Tomatoes, basil | Fennel |
| Carrots, onions | Kohlrabi |
| Spinach, lettuce | Apricot trees |
Cucumbers
| Good Companions | Bad Companions |
|---|---|
| Beans, peas | Potatoes |
| Corn, sunflowers | Aromatic herbs (sage, mint) |
| Radishes, lettuce | Melons (compete for space) |
Why it works: Corn provides a trellis. Radishes repel cucumber beetles.
Beans & Peas
| Good Companions | Bad Companions |
|---|---|
| Corn, squash | Onions, garlic |
| Carrots, beets | Chives |
| Cucumbers | Fennel |
Why it works: Legumes fix nitrogen in soil, feeding heavy feeders like corn.
Squash & Zucchini
| Good Companions | Bad Companions |
|---|---|
| Corn, beans | Potatoes |
| Nasturtiums, marigolds | Brassicas |
| Radishes |
Carrots
| Good Companions | Bad Companions |
|---|---|
| Onions, leeks | Dill |
| Tomatoes, lettuce | Parsnips |
| Rosemary, sage |
Why it works: Onions mask carrot scent from carrot flies. Carrots repel onion flies.
Lettuce & Greens
| Good Companions | Bad Companions |
|---|---|
| Carrots, radishes | Celery |
| Strawberries | |
| Chives, garlic |
Why it works: Tall plants (tomatoes, corn) provide shade for cool-weather greens.
Brassicas (Cabbage, Broccoli, Kale)
| Good Companions | Bad Companions |
|---|---|
| Onions, garlic | Tomatoes |
| Celery, beets | Strawberries |
| Chamomile, dill | Peppers |
The Three Sisters: Classic Companion Planting
The most famous companion planting combination:
- Corn — Provides a trellis for beans
- Beans — Fix nitrogen for corn and squash
- Squash — Large leaves shade soil, retain moisture, deter weeds
Plant corn first. When 6 inches tall, plant beans at the base. Plant squash between corn mounds.
Plants That Help Everything
These are universal companions:
- Marigolds — Repel aphids, beetles, nematodes
- Nasturtiums — Trap crop for aphids (they attack nasturtiums instead)
- Borage — Attracts pollinators, deters tomato hornworms
- Chamomile — Improves flavor of nearby plants
Plants to Keep Isolated
- Fennel — Inhibits growth of most vegetables. Plant separately.
- Walnut trees — Roots release juglone, toxic to tomatoes and peppers
- Mint — Spreads aggressively. Grow in containers.
How to Use This Information
Planning a garden with companion planting in mind takes time. You need to consider:
- Which vegetables you want to grow
- How much space each needs
- Which companions work together
- Planting timing for each crop
Skip the spreadsheet. Our AI Garden Planner automatically considers companion planting when creating your layout. Tell it what you want to grow, and it handles the rest.
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