Ethan BrooksBy Ethan Brooks

Updated November 2026

A companion planting garden planner lets you map out which vegetables, herbs and flowers share a bed, how far apart they should sit, and where each one goes from season to season. In this guide you will build a simple plan on paper or in a spreadsheet, check every pairing against known friends and foes, and set up a rotation schedule so your soil stays productive year after year.

Why Plan Companion Planting Before You Plant

Companion planting works best when it is designed rather than improvised. Putting basil next to tomatoes or marigolds near cucumbers sounds simple, but the benefits depend on spacing, timing and how tall each plant grows. A written plan catches conflicts early, such as a tall corn stalk shading a row of lettuce, or two heavy feeders competing for nitrogen in the same spot.

Shopping for one? See our guide: Companion Planting Ground Cherry: 7 Best Seed Picks for Your Garden (2026).

A planner also helps you keep track of what went where. Without records, most gardeners end up planting the same family in the same bed two years running, which invites soilborne disease. For a broader look at the principles, see What Does Companion Planting Mean? Pairings and Pitfalls.

Step 1: Measure Your Beds and Draw a Map

Start with accurate dimensions. Measure each bed’s length and width in inches or feet, then sketch it to scale on graph paper, using one square per foot or per 6 inches. Mark the location of any fixed features: a fence, a water spigot, a tree whose roots or shade will matter, or a path you need to keep clear.

If you are working with a standard layout, a 4×8 bed gives you 32 square feet, which is enough for roughly eight to ten vegetable types depending on how many plants each one needs. For a detailed breakdown, read Companion Planting 4×8 Raised Bed Vegetable Garden Layout: 7 Best Plans Compared.

Checklist: Information to Record for Each Bed

  • Bed dimensions and orientation (north–south beds get more even sun)
  • Sun exposure in hours per day, noted at the start of the season
  • Soil type and whether the bed is raised, in-ground or in containers
  • Irrigation access and drainage behavior after rain
  • Crop family planted there last season

Step 2: Sort Crops by Size, Sun Needs and Family

Before you place anything, group your plants into three categories. Tall crops (corn, pole beans, indeterminate tomatoes, trellised cucumbers) go on the north or shaded side of a bed so they do not block light. Medium crops (peppers, eggplant, bush beans, brassicas) fill the middle. Low crops (lettuce, radish, carrots, herbs such as parsley) sit on the south or sunny edge.

Next, note the plant family for each crop. Tomatoes, peppers, eggplant and potatoes are all nightshades. Cabbage, broccoli, kale and radish are brassicas. Keeping families apart from one season to the next is the foundation of crop rotation, which the planner should enforce automatically by flagging repeat plantings.

Step 3: Build Your Pairing Matrix

A pairing matrix is a grid listing each crop along both axes, with cells marked as beneficial, neutral or avoid. It is the core of any companion planting garden planner. Fill it in using well-established, widely repeated pairings and treat them as starting points rather than guarantees.

Crop Good Companions Keep Apart Notes
Tomato Basil, marigold, carrot, parsley Potato, fennel, brassicas Potato shares blight and pests with tomato
Cucumber Nasturtium, radish, dill, marigold Sage, aromatic herbs in quantity Nasturtium is often used as a trap crop for aphids
Onion Carrot, beet, lettuce Peas, beans Onions are often reported to deter carrot fly
Pea and bean Carrot, radish, cucumber, corn Onion, garlic, leek Legumes add nitrogen; alliums can stunt them
Strawberry Lettuce, spinach, borage Brassicas, fennel Keep plants at least 12 inches apart

For a more complete reference, compare options in Top 7 Best Companion Planting Chart Picks for Your Vegetable Garden or review Herb Companion Planting Guide: 7 Best Picks for Your Garden (2026) if your plan leans heavily on culinary herbs.

Step 4: Set Spacing Based on Mature Size

Spacing is where many plans fail. Use the mature width of each plant, not the transplant size. Common starting distances for intensive beds include:

  1. Lettuce, spinach and radish: 4 to 6 inches apart
  2. Bush beans and carrots: 3 to 4 inches apart
  3. Peppers and eggplant: 18 inches apart
  4. Determinate tomatoes: 24 inches apart; indeterminate tomatoes: 30 to 36 inches
  5. Winter squash and pumpkin: 36 to 48 inches apart in open ground

Check the seed packet for the specific variety, since compact cultivars often need less room. Entering these numbers into your planner lets it calculate how many plants fit per bed and warn you when a row is overcrowded.

Step 5: Plan Succession Plantings

Once your main layout is drawn, schedule successions. Quick crops such as radish (about 25 to 30 days), baby lettuce (about 30 days) and bush beans (about 50 to 60 days) can fill gaps after early spring harvests. Note the planting date and expected harvest date for each, and make sure the companion you choose for the second crop suits the first crop’s remaining neighbors.

For season-long bed planning, Companion Vegetable Garden Planting: A Step-by-Step Guide for 2026 walks through timing in more detail.

Step 6: Build a Rotation Schedule

A rotation plan moves each plant family to a new bed every year, typically on a three- to four-year cycle. Use a simple numbered system: label beds A through D, list the families in each, and shift them one bed clockwise each season. Your planner should show the previous year’s layout beside the current one so you can confirm nothing repeats.

Rotation also helps you plan companions for the next season. After a heavy-feeding brassica bed, a legume planting in the same spot can help restore nitrogen. For an example of a bed built around this idea, see Raised Bed Garden Layout Companion Planting: 6 Best Setups for Home Gardens.

Tools You Will Need

  • Graph paper or a digital layout tool
  • A tape measure and a notebook for records
  • Seed packets with spacing and days-to-maturity printed on them
  • A soil test kit or extension service sample, to inform amendments
  • Labels or stakes for marking bed IDs

Common Mistakes to Avoid

  • Trusting every pairing claim. Many companion lists repeat folklore. Favor pairings supported by extension resources and your own observations.
  • Ignoring height. A tall plant placed north of a short one is usually fine; the reverse can shade out the smaller crop.
  • Planning spacing for seedlings. Plants grow, so crowded beds in June often become disease-prone by August.
  • Skipping rotation records. Without written history, repeat plantings are easy to miss.
  • Overplanting herbs. Strong herbs like sage and mint can suppress neighboring crops when planted in quantity.

Tips for Keeping Your Planner Useful

  • Update the plan at mid-season and note what actually grew well or poorly.
  • Photograph each bed in late spring and late summer to compare growth against your drawing.
  • Keep one master file so you can compare several years of rotation history at a glance.
  • Revise your matrix when you learn something from your own garden; local conditions matter more than general charts.

A few basic supplies make a planner easier to keep up with. A sturdy, weather-resistant notebook or a set of plant markers lets you record bed IDs and planting dates directly in the garden.

  • Waterproof garden notebook: Paper survives the rain and damp soil better than most, so records stay readable through the season. View on Amazon
  • Metal plant markers with write-on surfaces: These hold up to sun and weather and keep labels clear for succession and rotation tracking. View on Amazon
  • Soil test kit: A basic pH and nutrient kit helps you match crops to conditions before you commit a bed. View on Amazon

FAQ

What is a companion planting garden planner?

It is a layout tool, either paper or digital, that combines a bed map with crop pairings, spacing, planting dates and rotation history. It helps you apply companion planting principles consistently.

Do I need special software to plan companion plantings?

No. Graph paper and a spreadsheet work well. Many gardeners prefer a simple grid because it is easy to update in the field.

How far apart should companion plants be?

Spacing depends on mature size, not companionship. Follow the seed packet or the plant’s known width, then use the companion relationship to decide which crops share the same bed.

How often should I rotate crops?

A three- to four-year cycle is widely recommended for vegetable families, which reduces the buildup of soilborne disease and pests.

Are companion planting benefits proven?

Some pairings have research support, such as trap cropping and attracting beneficial insects, while others rest mainly on long-standing gardening practice. Test them in your own beds and keep notes.

Can I use a companion planner for containers?

Yes. Treat each container as a small bed, and check container size against the mature spread of each plant before pairing.

What should I record each season?

Record planting and harvest dates, varieties, pest or disease problems, weather events and yield notes. These details make next year’s plan far more accurate.

When should I consult a professional?

If you suspect a persistent soil disease or nutrient problem, a local cooperative extension office can test your soil and advise on management.

Conclusion

A companion planting garden planner turns good intentions into a repeatable system. Measure your beds, sort crops by size and family, build a pairing matrix, and schedule rotations. Revisit the plan each season, and your beds will become more productive and easier to manage.

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.