Fertilizer for Garlic: NPK Guide and Application Rates
Garlic is typically planted in fall and harvested the following summer, with most of its fertilizer needs concentrated in a spring growth window. Like onions, leaf count determines bulb size, so nitrogen feeding during early spring growth is critical for large heads.
Quick Reference
What NPK Ratio is Best for Garlic?
The recommended NPK ratio for garlic is 10-10-10. A balanced 10-10-10 feeds all three macronutrients equally, which works well when soil tests show no single deficiency.
Garlic NPK needs shift at each growth stage. Balanced feed at fall planting time during the Seedling phase, then reduce nitrogen when scapes appear (hardneck) or in late spring (softneck) once flowering begins.
NPK by Growth Stage for Garlic
| Growth Stage | NPK Ratio | Notes |
|---|---|---|
| Seedling | 10N 10P 10K N 10% Nitrogen: leaf and stem growth P 10% Phosphorus: roots and flowers K 10% Potassium: health and disease resistance Learn more about NPK | Balanced feed at fall planting time |
| Vegetative | 21N 0P 0K N 21% Nitrogen: leaf and stem growth P 0% Phosphorus: roots and flowers K 0% Potassium: health and disease resistance Learn more about NPK | Nitrogen-heavy feeding in early spring when growth resumes |
| Flowering | 5N 10P 10K N 5% Nitrogen: leaf and stem growth P 10% Phosphorus: roots and flowers K 10% Potassium: health and disease resistance Learn more about NPK | Reduce nitrogen when scapes appear (hardneck) or in late spring (softneck) |
| Fruiting | 0N 0P 0K N 0% Nitrogen: leaf and stem growth P 0% Phosphorus: roots and flowers K 0% Potassium: health and disease resistance Learn more about NPK | Stop all fertilizer 3-4 weeks before harvest |
When Should You Fertilize Garlic?
In zone 3, start fertilizing garlic in April. In zone 10, begin as early as January. Apply every 3 weeks through the growing season.
Which Zones Can Grow Garlic?
Garlic grows in USDA zones 3 through 10, spanning a 8-zone range.
Fertilization Start by Zone
| Zone | Start Month |
|---|---|
| Zone 3 | April |
| Zone 4 | April |
| Zone 5 | March |
| Zone 6 | March |
| Zone 7 | February |
| Zone 8 | February |
| Zone 9 | January |
| Zone 10 | January |
What Are the Best Fertilizer Products for Garlic?
Look for products with an NPK close to 10-10-10. Espoma Garden-tone is the most popular choice among home gardeners for garlic.
- Espoma Garden-tone
- Down to Earth Blood Meal
- Dr. Earth Vegetable Garden Fertilizer
Prices vary by retailer and region. Check current pricing before purchasing.
Container and Raised Bed Adjustments for Garlic
Container garlic needs a deep pot (10+ inches) with light liquid feeding every 3 weeks in spring; stop once scapes appear
Common Fertilizing Mistakes with Garlic
- Skipping the spring nitrogen window results in small bulbs with few cloves
- Late-season nitrogen delays bulb curing and causes neck rot
- Planting cloves too shallow in cold zones leads to winter heaving
Tips for Fertilizing Garlic
- Apply a light dose of balanced fertilizer at fall planting for root establishment
- Begin nitrogen feeding in early spring as soon as green growth emerges
- Stop all fertilizing when scapes appear (hardneck) or about 4 weeks before harvest
Organic Fertilizer Alternatives for Garlic
Sources
Source:Ohio State CFAES - Growing Garlic in the GardenLast updated: