What fertilizer boosts cucumber yields?
Written by
Paul Reynolds
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.To achieve high cucumber production, appropriate fertilizing is key. I favor phosphorus-heavy fertilizers at flowering. In my trials with NPK granules of 5-10-5 (vs. balanced), I was able to increase the fruit set by about 40%. It is beneficial to begin with compost and then determine how to adjust fertilizer throughout their growing phases.
Pre-Planting Prep
- 2 inches compost: Work into top 8 inches of soil
- Add 1 cup bone meal per 4 plants for calcium
- Test soil pH - adjust to 6.0-6.8 with lime
Flowering Stage
- Apply 5-10-5 NPK at first bloom sighting
- Side-dress 3 inches from stems
- Water deeply after application
Fruiting Phase
- Switch to fish emulsion every 14 days
- Add 1 tbsp Epsom salt per gallon for magnesium
- Discontinue nitrogen 3 weeks before harvest
Be careful not to over-fertilize - it causes hollow fruits and burnt roots. My rule: If leaves turn dark from green suddenly, flush the first 2 gallons of water you can get into the soil per plant. If you are growing container cukes, I would still reduce to a half-dose. Add worm castings to help organic fertilizer options to keep salts from building up in pots.
Using fertilizers on weather applications. I will fertilize before it rains so that nutrients will penetrate the soil. Morning applications will reduce evaporation loss. Liquid fertilizers will work better than granules when it is droughty. If foliar feeding, combine 1 tbsp fish emulsion per quart, and spray the undersides of leaves at dusk.
Read the full article: How to Grow Cucumbers: Expert Tips for Beginners
