The Insectary Strip
A 4×6 border of flowering plants chosen for the evidence behind them — sweet alyssum for hoverflies, borage for pollination, calendula and dill for predatory wasps.
The plan
Each square is one square foot; the number is how many plants go in it at recommended spacing. North is the top of the plan — the tallest crops sit there so they don't shade the rest.
No recorded bad pairings between neighbouring squares in this plan.
Why it's arranged this way
This is companion planting's best-evidenced idea, separated from its worst. Rather than scattering flowers among vegetables hoping to repel pests, an insectary strip beside the vegetable beds feeds the adult stage of predators whose larvae eat aphids. Alyssum-associated aphid suppression has been measured up to 50 feet away.
- Plant this beside your vegetable beds, not inside them. The evidence supports a nearby insectary; the mixed-blend-scattered-among-crops version tested no better than nothing at all.
- Nasturtium is a trap crop, not a repellent — it draws aphids in. That is useful only if you actually manage it; left alone, an infested trap crop makes the problem worse.
- Sweet alyssum is a brassica. Count it in your brassica rotation rather than treating it as a break crop, which most charts get wrong.
What's in it, and when to plant
| Crop | Squares | Plants | Start indoors | Plant outside |
|---|---|---|---|---|
| Sweet Alyssum | 6 | 24 | Feb 13 – Feb 27 | Mar 27 – Apr 9 |
| Borage | 4 | 4 | — | Apr 10 – Apr 23 |
| Calendula / Pot Marigold | 4 | 16 | Feb 13 – Feb 27 | Mar 27 – Apr 9 |
| Dill | 4 | 4 | — | Apr 3 – Apr 16 |
| Sunflower | 4 | 4 | Mar 20 – Mar 27 | Apr 17 – Apr 30 |
| Nasturtium | 2 | 2 | Mar 13 – Mar 20 | Apr 17 – Apr 30 |
What you'll need
Bill of materialsSoil and equipment
- Raised bed soil, 12 in deep 24 cu ft · 16 bags · 0.889 cu yd
- Drip irrigation or soaker hose
- Deep container if not planting in ground
- Straw or leaf mulch
- Stakes and garden twine
Seed for this bed
- Sweet Alyssum seeds 24 plants · 6 sq
- Borage seeds 4 plants · 4 sq
- Calendula / Pot Marigold seeds 16 plants · 4 sq
- Dill seeds 4 plants · 4 sq
- Sunflower seeds 4 plants · 4 sq
- Nasturtium seeds 2 plants · 2 sq
Soil volume is calculated from this bed's footprint at 12 inches deep — adjust it on the soil calculator. Plant counts come from square-foot density for each crop. As an Amazon Associate we earn from qualifying purchases. Equipment is listed because the crops in this plan need it, not because it is sponsored.
Other layout plans
The Beginner 4×8 Bed
The standard first raised bed: eight crops that are hard to kill, spaced properly, with nothing planted next to something it fights with.
4 × 4 ftThe Cut-and-Come-Again Salad Bed
A 4×4 bed of fast greens and roots that you harvest continuously rather than all at once. Ready in six weeks, productive for months.
4 × 4 ftThree Sisters
Corn, beans and squash grown together — the one traditional polyculture with measured evidence that it out-produces the same area grown separately.
6 × 4 ftThe Salsa Bed
Everything for a bowl of salsa in one 4×6 bed: tomatoes, peppers, onions and cilantro, timed so they are ready together.
4 × 4 ftThe Partial Shade Bed
For the bed that only gets three to five hours of sun. Leafy crops and roots that genuinely prefer it, rather than fruiting crops that will merely survive.