Tomato Container Soil Mix

Solanum lycopersicum

Heavy-feeder tomato soil mix optimized for indeterminate and determinate varieties in containers.

Container:
10-15 gal indeterminate / 5-7 gal determinate
pH:
6–6.8
EC:
2–3.5 mS/cm
Sun:
6–8 hr

Components

Percentages by volume. Quantities scaled for a 10-gallon container (US units).

Component % Amount
Quality potting mix
Base structure, initial nutrients
30% 12 qt
Coco coir (low-EC, buffered)
CEC, moisture buffering
25% 10 qt
Perlite
Drainage, aeration
20% 8 qt
Vermicompost / Worm castings
Nutrients, microbes, growth hormones
12% 5 qt
Aged compost
Microbial diversity
8% 3 qt
Charged biochar
Long-term CEC, nutrient retention
5% 2 qt

Per-container amendments

Scaled linearly to your container size. Apply at transplant or as side-dress per the notes on each line.

Growing notes

- Bury 2/3 of seedling stem at transplant — adventitious roots give 2-3x root mass. - BER is almost always a calcium uptake problem from inconsistent watering, not Ca deficiency. - Heavy mulch (2-3") keeps soil moisture even, prevents BER. - Switch to 2-5-5 bloom blend once fruiting begins. - Cage or stake immediately at transplant.

Want to scale this to a different container size, save it to a plot plant, or track applied dates? Open it in the interactive calculator.

References

  1. Peat moss and 1:2 cocopeat:peat moss top tomato biomass; vermicompost+cocopeat matched peat moss — Aslan & Bayrak (2025) . J Soil Sci Plant Nutr
  2. Cocopeat produced longest plant height vs perlite alone (tomato) — Mavrona et al. (2001)