Ethan BrooksBy Ethan Brooks

Updated November 2026

A companion planting chart for a square foot garden tells you which vegetables grow well side by side and which ones compete or attract the same pests. Used correctly, it helps you fill each square with the right crop, space plants without guesswork and get more yield from a small bed. This guide shows you how to read a chart, build your own version for your grid and avoid the most common layout errors.

Understand How the Chart Fits a Square Foot Grid

Square foot gardening divides a 4-foot by 4-foot bed into sixteen 1-foot squares. Each square holds a set number of plants based on their mature size: one plant per square for large crops like tomatoes, four for medium crops like bush beans, and sixteen for small crops like carrots or radishes. A companion chart works inside that grid, so the question is not only “what grows well with what?” but also “how many of each fit in a square?”

Shopping for one? See our guide: 6 Best Garden Layout Free Printable Printable Companion Planting Charts (2026): Our Picks.

Most charts rate pairings as good, neutral or poor. Good pairings share a square or sit next to each other without harm. Poor pairings, such as beans near onions, slow one or both crops. Treat the chart as a starting point, since local climate, soil and pest pressure all change results.

Build Your Own Companion Planting Chart

A printed chart from a reliable extension service or a published square foot gardening guide works well, but a chart tailored to your crops is more useful. Follow these steps:

  1. List every vegetable, herb and flower you plan to grow this season.
  2. Write the plants-per-square number next to each crop (for example, 1 tomato, 4 bush beans, 16 carrots).
  3. Create a grid with one row per crop and one column per companion. Mark each pair as good, neutral or avoid.
  4. Add notes on sun and water needs so you can group crops with similar requirements in the same bed.
  5. Keep the chart with your garden journal and update it after each season.

If you want a ready-made starting point before you customize, see Square Foot Gardening Printable Companion Planting Chart: A Practical Guide (2026), which covers the common pairings in printable form.

Plan Your Square Foot Layout with Pairings in Mind

Once you have your chart, sketch the 4 by 4 bed on graph paper. Place tall crops on the north side so they do not shade shorter plants. Put trailing or spreading crops such as squash on the edges, and give each square a single crop or a compatible group. Keep a 1-foot path or a clear border between beds for access.

Group plants with similar water and feeding needs. Heavy feeders like tomatoes and peppers belong together, while light feeders like lettuce or herbs can share a square. For a detailed walkthrough of arranging companions in a grid, read Companion Planting in a Square Foot Garden: A Step-by-Step Guide.

Check Spacing Before You Plant

Spacing errors are the most common reason square foot gardens underperform. Use a square foot grid frame or string lines to mark each square before you sow or transplant. Thin seedlings to the number listed on your chart, not to what looks sparse. Overcrowding invites disease, while gaps waste space.

Plan Succession Planting and Rotation

Square foot gardens reward succession planting. When a square of radishes finishes in four weeks, replant it with bush beans or lettuce. Your chart should note days to maturity so you can schedule replants. Also avoid planting the same crop family in the same square two seasons running, since that builds up soil-borne disease.

Common Mistakes

  • Planting beans next to onions or garlic, which can stunt bean growth.
  • Ignoring plants-per-square numbers and overcrowding the grid.
  • Placing tall crops where they shade the whole bed.
  • Assuming a chart applies unchanged in every climate. Check local extension advice.
  • Forgetting to update the chart after a poor season.
  • Square foot grid frame – A frame or string grid makes it easy to mark sixteen squares accurately before planting. View on Amazon
  • Garden journal – A dedicated notebook keeps your pairing notes, planting dates and harvest results in one place. View on Amazon

FAQ

Do I need a printed chart to use companion planting in a square foot garden?

No. A chart is helpful for remembering pairings, but the principles of spacing and compatible groupings work even if you keep notes in a simple list. Start with a few reliable pairs and expand over time.

How many plants go in each square?

It depends on mature size. Large crops like tomatoes take one square each, medium crops like bush beans take four, and small crops like carrots or radishes take sixteen. Always check the spacing for each variety.

Can companion planting replace pest control?

Not entirely. Companion pairings can reduce some pest problems, but monitoring, handpicking and crop rotation are still needed. For persistent pest or disease issues, consult your local cooperative extension office.

Conclusion

A companion planting chart turns a square foot grid into a planned system rather than guesswork. Build or print a chart that matches your crops, sketch your layout before planting and check spacing as you sow. Update your notes each season and your bed will improve year after year.

Ready to choose one?

Ethan Brooks

About Ethan Brooks

Ethan Brooks is part of our editorial team and reviews and edits our vegetable & edible gardening guides, checking product details against manufacturer specifications and owner feedback.