Wicked Growth · Fertilizer Guide
Garlic + Onion Fertilizer
NPK 10-10-10Non-Organic
Garlic & Onion Fertilizer 10-10-10 is a balanced granular fertilizer specifically designed to support the full development of allium crops — from early leaf formation through bulb sizing and harvest. The equal ratio of 10% nitrogen, 10% phosphorus, and 10% potassium feeds both the green tops that power photosynthesis and the undergroun...
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Nutrient Breakdown
N · Nitrogen
10%
Encourages healthy green tops that fuel bulb formation and sizing.
P · Phosphorus
10%
Supports strong root systems and early bulb development underground.
K · Potassium
10%
Improves bulb density, disease resistance, and storage quality after harvest.
Derived from: Urea, Monoammonium Phosphate (MAP), Muriate of Potash (MOP)
Overview
What It Is
This is a crop-specific 10-10-10 fertilizer formulated with the unique growth cycle of allium crops in mind. Onions and garlic have distinct nutritional demands — they need steady nitrogen to build the leaf canopy that fuels bulb development, phosphorus for root establishment (especially important for fall-planted garlic), and potassium for the bulb density and disease resistance that determines storage quality.
Unlike the 5-10-10 formulas designed for fruiting crops and bulbs, the Garlic + Onion formula provides a full 10% nitrogen because alliums need robust top growth to drive bulb sizing. Each leaf on an onion plant corresponds to one ring on the bulb — more healthy leaves means a bigger onion. The balanced 10-10-10 ratio ensures all three macronutrients support this growth cycle without creating deficiencies.
Unlike the 5-10-10 formulas designed for fruiting crops and bulbs, the Garlic + Onion formula provides a full 10% nitrogen because alliums need robust top growth to drive bulb sizing. Each leaf on an onion plant corresponds to one ring on the bulb — more healthy leaves means a bigger onion. The balanced 10-10-10 ratio ensures all three macronutrients support this growth cycle without creating deficiencies.
Crop Fit
Best For
This fertilizer is optimized for all allium family crops. Storage onions (yellow, red, white) benefit from the balanced feeding schedule that builds large bulbs with tight skins. Sweet onions like Walla Walla and Vidalia respond well to the steady nitrogen for maximum sizing. Hardneck garlic varieties benefit from fall application at planting and spring side-dressing as scapes emerge. Softneck garlic, shallots, and leeks all thrive with the consistent N-P-K delivery this formula provides.
Application Rates
How Much to Use
| Garden & beds | 1/2-1 cup per 10 sq ft |
|---|---|
| Lawn | N/A — crop-specific fertilizer formulated for alliums, not turf |
| Trees & shrubs | N/A — formulated for allium crops, not trees |
| Containers | 1 tbsp per gallon of soil |
| Frequency | Every 4-6 weeks during growing season. Stop 2-3 weeks before harvest. |
Step by Step
How to Apply
1
New Planting
For new plantings, mix 1/2 to 1 cup per 10 sq ft into soil before planting. Incorporate into the top 4–6 inches where roots will develop.
2
Side-Dress
For established crops, side-dress with 1/2 cup per 10 linear feet of row when tops reach 4–6 inches tall.
3
Water In
Water thoroughly after every application to activate nutrients and prevent fertilizer burn on developing roots.
4
Reapply
Reapply every 4–6 weeks during active growth to sustain steady nutrient supply through the bulbing phase.
5
Pre-Harvest Cutoff
Stop feeding 2–3 weeks before harvest to allow bulbs to cure properly. Continued feeding delays curing and reduces storage life.
6
Fall Garlic
For fall-planted garlic, apply at planting time and again in early spring when green shoots emerge. This supports both root and top growth.
For spring-planted onions, incorporate fertilizer into the bed before transplanting sets or seedlings. Side-dress once plants are established and actively growing. For fall-planted garlic, work fertilizer into the planting trench at clove planting time, then top-dress in early spring as green shoots emerge. Always water in after application and avoid contact with foliage to prevent burn.
Handling & Timing
Safety & Season
Safety & Storage
Store in original packaging in a cool, dry area. Avoid breathing dust during application. Wash hands after handling. Keep away from children, pets, and waterways.
Seasonal Notes
For fall garlic: apply at planting (September-November). For spring onions: apply at planting and side-dress through summer. Stop all feeding 2-3 weeks before harvest regardless of season. Not applied in winter when crops are dormant.
In Context
How It Compares
Compared to the 5-10-10 Garden & Tomato formula, this 10-10-10 provides double the nitrogen — important because alliums need strong top growth to size their bulbs, unlike fruiting crops where excess nitrogen hurts yields. Versus bone meal or organic alternatives, it delivers faster nutrient availability for the relatively short allium growing season. The balanced ratio avoids the excess nitrogen that can cause soft, poorly-storing bulbs while still providing enough N for leaf development.
Answers
Frequently Asked Questions
What is the best fertilizer for garlic and onions?
The best fertilizer for garlic and onions provides balanced nutrition with equal parts nitrogen, phosphorus, and potassium (10-10-10). Nitrogen fuels the green top growth that powers bulb formation through photosynthesis. Phosphorus supports strong root systems and early bulb development. Potassium improves bulb density, disease resistance, and storage quality. A balanced formula ensures allium crops receive steady, complete nutrition from planting through harvest. Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer 10-10-10 is specifically designed to grow bigger, more flavorful bulbs with excellent storage life.
When should I fertilize garlic?
For fall-planted garlic, apply fertilizer at planting time (usually October or November) and again in early spring when green shoots emerge. Side-dress once more when plants are 4–6 inches tall. Stop fertilizing garlic about 3–4 weeks before harvest (typically mid-June in northern climates) to allow bulbs to cure and develop papery wrappers. Over-fertilizing late in the season can delay maturity and reduce storage quality. Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer provides controlled-release granules for continuous nutrition throughout the growing season.
How much fertilizer do onions need?
Onions are moderate to heavy feeders. Apply fertilizer at planting by mixing ½–1 cup of 10-10-10 per 10 square feet into the soil. Once plants are established and tops are 4–6 inches tall, side-dress with ½ cup per 10 linear feet of row. Repeat every 4–6 weeks during the growing season. Stop fertilizing 2–3 weeks before harvest so bulbs can properly mature and cure. For container-grown onions, use 1 tablespoon per gallon of soil and reapply monthly. Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer 10-10-10 delivers the steady nutrition onions need for uniform, full-sized bulbs.
Can I use 10-10-10 fertilizer on garlic?
Yes, 10-10-10 is an excellent fertilizer choice for garlic. The balanced NPK ratio supports all phases of garlic growth — nitrogen drives strong leaf production that feeds bulb development, phosphorus encourages deep roots and clove formation, and potassium enhances bulb firmness and disease resistance. Many experienced growers prefer a balanced formula over high-nitrogen options because it promotes well-rounded growth rather than excessive foliage at the expense of bulb size. Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer 10-10-10 is optimized specifically for allium crops including garlic, onions, shallots, and leeks.
What types of onions and garlic can I fertilize with this product?
Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer works with all allium varieties including yellow, red, and white onions, sweet onions like Walla Walla and Vidalia, green onions and scallions, hardneck and softneck garlic, elephant garlic, shallots, leeks, and culinary chives. The balanced 10-10-10 formula provides consistent nutrition across all these allium types, supporting healthy top growth, strong roots, and well-formed bulbs regardless of variety.
How do I grow bigger garlic bulbs?
Growing bigger garlic bulbs requires consistent moisture, proper spacing (6 inches apart), rich soil with good drainage, and balanced fertilization throughout the growing season. Plant the largest cloves from your best heads — bigger seed cloves produce bigger bulbs. Fertilize at planting, again in early spring, and side-dress when plants are actively growing. Mulch with straw to retain moisture and suppress weeds. Remove scapes from hardneck varieties to redirect energy into bulb development. Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer 10-10-10 provides the balanced nutrition garlic needs to reach its full size potential.
Should I stop fertilizing onions before harvest?
Yes, you should stop fertilizing onions 2–3 weeks before harvest. Continuing to feed onions too late encourages continued green top growth instead of bulb maturation, which can result in soft, thick-necked bulbs that are difficult to cure and prone to storage rot. Once onion tops begin to fall over naturally, the plant is signaling that it is redirecting energy into the bulb. Allowing this natural process to finish without additional fertilizer produces firmer, better-curing onions. Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer is designed for reapplication every 4–6 weeks, making it easy to time your last application correctly.
