20-20-20 is one of the best-known water-soluble fertilizers, and the numbers mean it contains 20% nitrogen, 20% phosphorus and 20% potassium, a full balance of the major nutrients. That is why it is called a balanced fertilizer, and it suits most crops during their growth stages.
This article explains when to use 20-20-20, how to apply it as a foliar spray or through irrigation, the usual rates, and the mistakes that waste its benefit.
What does 20-20-20 mean?
- N 20% nitrogen: for vegetative growth and leaves.
- P 20% phosphorus: for roots and flowering.
- K 20% potassium: for plant strength and fruit quality.
- TE (trace elements): some products add iron, zinc, manganese and boron, which is a useful bonus.
The full explanation of NPK numbers is in NPK Fertilizer: What the Numbers Mean and How to Choose the Right Formula.
When should you use it?
- The vegetative growth stage, once the seedling is established.
- After stress: after pruning, a heatwave or transplanting.
- Houseplants and ornamentals as regular feeding.
- When you are not sure exactly what the plant lacks, as balanced general feeding.
When is it not the best choice?
- At transplanting, a high-phosphorus fertilizer is better for roots.
- During fruiting and fruit sizing, a high-potassium fertilizer is better.
How to apply it
1. Foliar spray
- Rate: 1 to 2 grams per litre of water, which is 100 to 200 grams per 100-litre drum.
- Method: spray the leaves until fully wet on both sides.
- Timing: early morning or late afternoon, not in the heat.
- Frequency: every 10 to 14 days depending on the plant's condition.
2. Through drip irrigation
- Vegetables and open-field crops: 200 to 400 grams per 1,000 m² per irrigation.
- A 500 m² greenhouse: half a kilo to one kilo per greenhouse per application.
- Fruit trees and palms: 200 to 300 grams per tree depending on age, dissolved in the irrigation water.
- Start with the lower rate for young plants and increase it as they grow.
- Flush the lines with clean water after fertigation so the drippers do not clog.
3. For houseplants
Dissolve 1 gram per litre of water and water with it once every two weeks during the growing season, reducing it in winter.
Common mistakes
- Increasing the rate for faster results: it burns roots and leaves.
- Spraying at midday: it scorches leaves and the fertilizer evaporates.
- Using it all season without change: each stage has different needs.
- Mixing it with calcium fertilizers in the same tank: it forms deposits and clogs drippers.
Products from Orkida
- Agroleaf Power 20-20-20, 15 kg: a balanced foliar fertilizer for all growth stages.
- Nitroleaf 20-20-20: a balanced foliar fertilizer to boost vegetative growth and strengthen roots.
- SAF Soluble NPK 20-20-20, 1 kg: balanced plant nutrition through the growth stages.
- Norus 20-20-20 + TE, 25 kg: 100% soluble for irrigation and foliar spraying with trace elements.
- Solucas NPK 20-20-20, 1 kg: water-soluble for growth and flowering.
- Pioneers 20-20-20 + Trace Elements, 25 kg: highly soluble for farms and large areas.
Frequently Asked Questions
Is 20-20-20 good for flowering?
It helps, but it is not the best for flowering and fruiting. At that stage, use a fertilizer with higher potassium.
How often should I spray it?
Every 10 to 14 days, at 1 to 2 grams per litre of water.
Can I use it for palms?
Yes, it works as balanced feeding through irrigation water, alongside a fertilizer programme suited to the palm's stage.
What is the difference between 20-20-20 and 19-19-19?
The difference in ratios is small, and both are balanced fertilizers. What matters is complete solubility and the quality of the trace elements.