Best Fertiliser for Cauliflower: Full Feeding Guide by Stage

Cauliflower is one of the most nutrient-demanding brassicas to grow. Its tight white head (called a curd) requires a strong, consistent nutrient supply throughout the entire growing cycle—from early leaf formation to curd development and harvest.

Without a structured feeding plan, cauliflower is prone to issues like:

Loose curds (poor compaction from potassium or calcium deficiency)
Bolting (shooting to seed due to stress or low nitrogen early on)
Leaf overgrowth with no head formation (overuse of nitrogen during curd stage)

What Nutrients Does Cauliflower Need?

Nitrogen (N): Fuels large, healthy leaf production in early stages
Phosphorus (P): Supports root growth and plant stability
Potassium (K): Essential for dense, compact curds and stress resistance
Calcium (Ca) & Magnesium (Mg): Prevent internal disorders like hollow stems and curd breakdown

Each stage of cauliflower development needs a different balance of nutrients. This is where your fertiliser strategy becomes crucial—and where CompleteGrow formulations are perfectly suited.

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Best Fertiliser Schedule for Cauliflower Plants

1. Early Growth (Weeks 1–4)

Goal: Promote leaf size, root expansion, and stem strength
Fertiliser: All Purpose Liquid NPK 20-20-20
Rate: 5 mL per litre of water every 7–10 days
Why: Balanced NPK encourages rapid leaf and crown growth without overstimulating flowering too early

2. Vegetative to Pre-Curd Stage (Weeks 4–8)

Continue: Feeding with 20-20-20 weekly
Optional Boost: Apply Cal-Mag Nutrients at 2.5 mL per litre every 2 weeks to prevent leaf deformation and future curd issues

3. Curd Formation (Weeks 8–12+)

Goal: Shift energy toward dense, uniform curd growth
Fertiliser: NPK 4-18-38 + CaMg
Rate: 5–6 g per 10 litres of water every 7–10 days
Why: Low nitrogen prevents excessive leaves; high phosphorus and potassium support flower head formation, firmness, and white curd colour

Important: Avoid applying high-nitrogen feeds after curds begin forming—this leads to leafy or distorted heads and delays maturity.

Extra Feeding Tips for Container or Poor Soil Cauliflower

For Pot-Grown Cauliflower

Use a lightweight potting mix and fertilise more frequently (every 5–7 days)
Leach soil monthly with clean water to prevent salt buildup from frequent feeding
Always use containers at least 30 cm deep and 30–40 cm wide per plant

For Clay or Sandy Soil

Clay: Add gypsum and coarse compost to improve drainage; water less often but deeply
Sand: Apply 20-20-20 more frequently (twice weekly) as nutrients leach rapidly

Common Fertiliser-Related Problems

Yellowing Curds: Often caused by lack of calcium or curds exposed to direct sun (blanching helps)
Leafy but no curd: Too much nitrogen, especially if not switched to 4-18-38 on time
Split or hollow heads: Sudden overwatering or potassium deficiency

Stick to a consistent feeding routine with correct timing, and you’ll get tight, white, market-quality cauliflower heads—whether you’re growing in garden beds, raised rows, or pots on the patio.