Broccoli Container Soil Mix
Brassica oleracea var. italica
Heavy-feeding cool-season brassica that needs even moisture and a fertile, slightly alkaline mix.
- Container:
- 5 gal fabric, one head per pot
- pH:
- 6–7
- EC:
- 1.8–2.4 mS/cm
- Sun:
- 6–8 hr
- Light:
- Full sun
Components
Percentages by volume. Quantities scaled for a 5-gallon container (US units).
| Component | % | Amount |
|---|---|---|
| Quality potting mix Base structure, initial nutrients | 40% | 8 qt |
| Aged compost Microbial diversity | 25% | 5 qt |
| Vermicompost / Worm castings Nutrients, microbes, growth hormones | 15% | 3 qt |
| Coco coir (low-EC, buffered) CEC, moisture buffering | 10% | 2 qt |
| Perlite Drainage, aeration | 10% | 2 qt |
Per-container amendments
Scaled linearly to your container size. Apply at transplant or as side-dress per the notes on each line.
- Balanced organic fertilizer (4-4-4 / 5-5-5) Mix in at transplant; side-dress at 4 inches tall.3–5 tbsp
- Garden lime If mix is below pH 6.5; clubroot suppression.1–2 tbsp
- Bone meal Slow phosphorus + calcium for head formation.2–3 tbsp
- Mycorrhizae inoculant At transplant on root ball.1 tbsp
Growing notes
- Use 50-60 day heat-tolerant varieties for spring; 60-85 day for fall.
- At least 1 inch water per week — moisture stress causes bitter, loose heads.
- Side-dress at ~4 inches tall with a balanced N source.
- Cut central head while still tight, before yellow flower buds open; side shoots follow.
- Rotate brassicas on a 4-year cycle to limit clubroot/black rot.
- Skim pH toward 7 with lime if needed — helps suppress clubroot.
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
- Growing broccoli in home gardens — University of Minnesota Extension . University of Minnesota Extension