Proper fertilization of cabbage is the difference between firm heads and leafy plants. Watered with too much nitrogen, you have luxuriant leaves: with too little, stunted plants, and insufficient heads. You must therefore feed regularly, at proper periods, in order to produce good heads of cabbage.
Initial Soil Prep
- Mix 2-3 inches compost into soil before planting
- Apply balanced 10-10-10 fertilizer at transplanting
- Ensure soil pH between 6.0-7.0 for nutrient uptake
Mid-Season Boost
- Apply nitrogen-rich fertilizer 5 weeks after planting
- Use fish emulsion or blood meal for organic options
- Side-dress plants keeping fertilizer 6 inches from stems
Pre-Harvest Phase
- Stop all fertilizing 3 weeks before harvest
- Switch to potassium-rich amendments to firm heads
- Test soil to avoid excess nutrients
When the leaves start making their first leaf circles, apply a mid-season N boost. Timing is critical; excessive nitrogen can cause excessive leaf growth and hinder head development. It is essential to water deeply after application to prevent root burning from nitrogen and to ensure a uniform distribution of nitrogen.
Do not over-fertilize, as this creates issues. Excess nitrogen attracts many types of feasting insects while delaying heading. Chemicals used for fertilizing will build up salts over time, damaging plant root systems. If you notice the tips of your plant's leaves beginning to burn, flush the soil with water.
Organic options, such as compost tea and worm castings, provide slow-release nutrition. Apply every 3 weeks during growth. These improve soil structure while feeding plants. They rarely cause nutrient burns.
Stop fertilizing completely 3 weeks before harvest. This prevents soft heads and improves storage quality. Test soil annually to adjust your fertilization plan for future crops.
Read the full article: 5 Key Signs: When to Harvest Cabbage
