Cucumbers are a delicious summer vegetable that are easy to grow, but getting large, straight cucumbers requires some extra nutrition. While you can purchase chemical fertilizers, homemade organic fertilizers are a safe, inexpensive way to fertilize your cucumber plants. The right nutrients fed to the soil and plants will help cucumbers grow fast, stay healthy, and produce abundantly all season long.
In this comprehensive guide, you’ll learn multiple recipes for homemade fertilizers that will give your cucumber plants the nutrients they crave.
Why Cucumbers Need Fertilizer
Cucumbers are heavy feeders that require a lot of nutrition to support their rapid growth and heavy yield. Like all vegetable plants, cucumbers need a constant supply of nitrogen, phosphorous, and potassium, as well as other macronutrients and micronutrients.
Nitrogen promotes lush, green foliage and stem growth. An abundance of nitrogen will give your cucumber vines the energy to grow long and become thick and robust.
Phosphorous supports root growth, flower production, and fruit development. This nutrient ensures cucumber plants have an extensive root system to uptake water and nutrients. Strong roots allow more flowers to form which in turn produces more cucumbers.
Potassium is key for overall plant vigor and disease resistance. Potassium helps cucumbers grow large and straight, plus it makes their skin thick and prickle-free. Plants with enough potassium can better handle pest and disease pressures.
Without adequate nutrition, cucumber vines will be stunted and yellow, flowers and fruit won’t develop properly, and yields will be low. Using organic homemade fertilizers that provide a balanced diet of nutrients keeps plants vigorous and producing all season long.
Homemade Fertilizer Recipes for Cucumbers
It’s easy to whip up homemade cucumber fertilizers using ingredients you likely have around the house and yard. Here are some top homemade fertilizer recipes.
Steep compost in water for a nutrient-rich liquid fertilizer. Place shovelfuls of finished compost into a burlap sack or an old pillowcase. Tie the bag closed and let it soak in a large bucket of water for a day or two. The water will extract the beneficial microbes and nutrients from the compost. Dilute the compost tea with water, then pour it directly on the soil around your cucumber plants or apply through drip irrigation. Make fresh batches of compost tea every few weeks.
Manure from cows, horses, chickens, rabbits or other animals is an excellent source of nitrogen, phosphorous, and potassium for plants. To make manure tea, soak manure in water for at least a week. Dilute the resulting ‘tea’ until its color turns light brown and has no strong odor. Apply it to cucumber plants by hand or through drip irrigation.
Seaweed is naturally high in potassium, magnesium, iron and zinc. It contains plant hormones that stimulate root growth and fruiting. To make liquid seaweed fertilizer, fill a large bucket with water and add a generous amount of dried seaweed. Let it soak for 4-6 weeks until it turns dark brown. Dilute the seaweed extract with 8-10 parts water and apply to your cucumber plants weekly.
Fish emulsions supply nitrogen and phosphorous in a fast-acting organic form. Make your own fish emulsion by filling a jar with fresh fish scraps from a local fish market or your own catch. Add an equal amount of water with some lactobacillus bacteria and let it steep for 2-4 weeks. Strain out the solids, dilute the remaining liquid until it no longer smells strongly, and apply it to cucumber plants.
Banana Peel Fertilizer
Banana peels are a great source of potassium, calcium, and magnesium. Simply bury peeled bananas 1-2 inches below the soil surface near your cucumber plants. As the peels decompose, nutrients will be released directly to the cucumber roots.
Epsom salt (magnesium sulfate) quickly corrects magnesium deficiencies and helps plants do efficient photosynthesis. For cucumbers, dissolve 1-2 tablespoons epsom salt per gallon of water. Spray this mixture directly on the cucumber foliage to correct stunted growth and yellow leaves.
The leftover ash from burning clean, untreated wood is high in potassium and calcium. Sprinkle a light dusting of wood ash around your cucumber plants every 2-3 weeks. Avoid using ash from charcoal briquettes or pressure-treated lumber.
Used coffee grounds contain nitrogen, potassium, phosphorous, and other trace minerals. Sprinkle them lightly on top of the soil or mix into the top few inches. Limit coffee grounds to no more than 20% of your soil mix.
Fresh grass clippings are high in nitrogen which makes them an excellent cucumber fertilizer. Let your grass clippings fully dry out in the sun before using. Apply a 1-2 inch layer of dried grass clippings as mulch around your cucumber plants. Don’t use clippings from lawns that have been treated with herbicides.
When and How Often to Fertilize Cucumbers
Timing and frequency are important when fertilizing cucumbers for optimal result.
- Prepare the soil pre-plant by adding aged compost, manure, or other organic matter a few weeks before planting cucumber seedlings. This gives soil microbes time to start breaking down nutrients.
- Side-dress cucumber plants with additional homemade fertilizer when vines begin to run and flower. This boost ensures good pollination and fruit set.
- Fertilize again just as the first baby cucumbers start to form. A nutrient boost now helps the fruit grow quickly.
- Every 2-3 weeks after that, continue feeding plants with compost tea, manure tea, or other liquid fertilizers. This keeps plants vigorous and productive all season long.
- For dry homemade fertilizers like wood ash, coffee grounds or banana peels, re-apply every 2-3 weeks around each plant.
- Always water fertilizers into the soil after applying. Never apply fertilizer onto dry soil.
- Stop fertilizing 2-3 weeks before your expected final harvest. This allows time for the last fruits to fully mature. Excess nitrogen late in the season can inhibit ripening.
Follow these homemade fertilizer recipes and guidelines to grow your best cucumbers ever. With the right nutrition, your cucumbers will be abundant, flavorful, and bursting with nutrients from vine to table.
Common Cucumber Plant Problems
Even with ideal growing conditions and nutrition, cucumber plants can sometimes struggle with pest damage, disease, or environmental stresses. Here are some common cucumber plant problems and how to fix them.
1. Yellowing leaves – This can indicate a nitrogen deficiency or a soil pH imbalance. Try boosting nitrogen with compost tea or fish emulsion. Test soil pH and amend if needed to maintain a pH between 6-7.
2. Stunted vines – Poor nutrient levels, underwatering, root damage, or disease can retard vine growth. Check soil moisture and fertilize more consistently to encourage growth.
3. Flowers falling off – Hot, dry weather or inadequate pollination can cause cucumber flowers to drop before setting fruit. Try misting plants on very hot days and hand pollinating flowers using a soft brush.
4. Misshapen cucumbers – Low potassium and/or low boron causes oddly-shaped cucumbers. Fertilize plants with wood ash or compost to provide potassium. Spray leaves with diluted borax for supplemental boron.
5. Bitter flavor – Stress, high temperatures, or drought can cause bitter flavor. Ensure consistent moisture and pick fruit when immature to avoid bitterness.
6. Pests like cucumber beetles and squash bugs – Cover young plants with floating row covers until flowering. Handpick off pests, use insecticidal soap, or apply neem oil.
7. Diseases like powdery mildew – Improve air circulation and avoid wetting foliage. Apply neem oil or a sulfur fungicide weekly as prevention.
By identifying and treating these issues promptly, you can get your cucumber plants back to thriving again. Pay close attention to their needs throughout the growing season for the best harvest.