Smart Garden Planner

Companion planting explorer

Pick a crop to see which plants may help it, which share pests or diseases, and how strong the evidence is. Every pairing links to its source. If a pairing isn't listed, we don't have reliable evidence for it yet — we don't fill gaps with folklore.

Tomato

Solanum lycopersicum

Sun
Full sun
Water
Even moisture; water at the base
Soil
Well-drained soil, pH 5.5–7.0
Spacing
Follow cultivar and staking/caging requirements; preserve airflow
Growing guide source Full tomato companion guide →

Possible companions

  • Basil

    Extension guidance

    Basil may help mask tomato host cues from thrips.

    Penn State describes basil interplanting as host-cue masking. This does not establish improved tomato flavor, yield, or protection against all pests. Both favor sunny, well-drained sites.

    Spacing: Retain mature tomato and basil spacing; no universal pair-specific distance is established.

    Pests: Potential thrips mechanism, not a substitute for monitoring or integrated pest management.

    Penn State Extension · Herbs as plant partners
  • French marigold

    Research-supported

    Selected marigold cover crops can suppress certain nematodes before tomatoes.

    UF/IFAS supports selected Tagetes cultivars grown in the future vegetable bed for at least two months before vegetables. Effects depend on nematode species, cultivar and temperature. A few adjacent flowers are not proven broad pest repellents.

    Spacing: This is a preplant cover-crop strategy, not a recommendation to crowd flowers beside tomatoes.

    Pests: Identify the nematode and appropriate cultivar first; susceptible marigolds can increase nematodes.

    UF/IFAS · Marigolds and nematode management
  • Lettuce

    Extension guidance

    Early lettuce can be harvested as later tomatoes expand.

    University of Minnesota describes relay planting: an early crop nears maturity as the later tomato planting is introduced. This is timing and space use, not a pest or growth-stimulation claim.

    Spacing: Reserve mature tomato space; harvest lettuce before canopy crowding becomes substantial.

    Pests: No pest-control benefit is established by this relay-planting guidance.

    University of Minnesota · Companion planting

Use caution

  • Potato

    Extension guidance

    Tomatoes and potatoes share susceptibility to late blight.

    Both host Phytophthora infestans. Infected tubers or transplants and windblown spores can introduce disease. This is shared disease risk, not chemical incompatibility.

    Spacing: Preserve airflow. No safe separation distance is established; adjacent rows do not prevent airborne infection.

    Pests: Use healthy planting material and monitor both crops; rotation alone does not prevent airborne late blight.

    University of Minnesota · Late blight

All sourced pairings

Check pairings in your own beds

Smart Garden Planner flags companions and conflicts automatically as you add plants to a garden bed.

Reference version 2026-11-03. Information is educational; local conditions vary — check your local extension office.