Best Garlic & Onion Fertilizer (10-10-10): Balanced Nutrition for Bigger Bulbs, Stronger Flavor & Clean Curing Buy on Old Cobblers Farm
Garlic and onions have a unique growth cycle — fall root establishment, spring leaf push, then bulb sizing. This 10-10-10 feeds both phases with balanced NPK and a critical rule: stop feeding 2–3 weeks before harvest so bulbs cure clean and store long.
Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer
by Conventional Fertilizer — Littleton, NH
Aligned to Allium Growth Cycle
Garlic and onions grow in distinct phases: fall rooting, spring leaf expansion, then bulb formation. This formula feeds the first two phases and steps back for the third — exactly how alliums want to eat.
More Leaves = Bigger Bulbs
Each garlic leaf corresponds to one bulb wrapper. More leaves = more wrappers = bigger, better-protected bulbs. 10% nitrogen fuels the leaf growth that directly determines bulb size.
Balanced P & K for Root & Bulb
10% phosphorus supports fall root establishment. 10% potassium strengthens bulb tissue quality, improves flavor compound development, and extends storage life.
Stop 2–3 Weeks Before Harvest
Critical: cease feeding 2–3 weeks before harvest. Continued nitrogen delays maturity and produces wet bulbs that won't cure properly for long-term storage.
110–220 sq ft Per Bag
At ½–1 cup per 10 sq ft, one 5 lb bag covers 110–220 sq ft of garlic or onion bed at planting. Side-dress uses the lighter rate.
Simple 2-Feed Program
Feed at fall planting (or early spring for onions), then side-dress once in mid-spring when growth resumes. Two applications and you're done.
All Allium Types
Hardneck garlic, softneck garlic, elephant garlic, onions, shallots, leeks, scallions, and chives — the entire allium family thrives on balanced feeding.
Trusted by 20,000+ Growers
Developed in Littleton, New Hampshire. Sold nationwide on Amazon, Walmart, eBay, and theoldcobblersfarm.com.
| NPK Ratio | 10-10-10 |
| Item Form | Granular |
| Coverage | ~110–220 sq ft at planting per 5 lb bag |
| Category | Conventional Fertilizer |
| Type | Flower & Garden |
| Sizes | 5 lb | 10 lb | 15 lb | 20 lb |
| NPK | 10-10-10 |
| Nitrogen | 10% |
| Phosphorus | 10% available phosphate |
| Potassium | 10% soluble potash |
| Form | Granular |
| Rate | ½–1 cup / 10 sq ft |
| Method | Incorporate at planting + spring side-dress |
| Frequency | 2x per season |
| Sizes | 5, 10, 15, 20 lb bags |
| Best For | Garlic (hardneck, softneck), onions, shallots, leeks |
| Note | Stop feeding 2–3 weeks before harvest for clean curing |
| Feature | Old Cobblers Farm™ Wicked Growth Garlic + Onion Fertilizer Old Cobblers Farm | Multi-Purpose 10-10-10 GreenView | Granular with Micros Supply Solutions | All Purpose Fertilizer Expert Gardener | Tomato & Vegetable MasterBlend | WonderFert All-Purpose Sunday | Multi-Purpose Organic MicroLife | Organic Enriched Veg WonderTree | Vegetable Food Rite Green | 10-10-10 All Purpose GroundWork | 10-10-10 All-Purpose MasterBlend |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NPK | 10-10-10 | 10-10-10 | 10-10-10 | 10-10-10 | 4-18-38 | 10-2-6 | 6-2-4 | 7-7-7 | 10-10-10 | 10-10-10 | 10-10-10 |
| Form | Granular | — | — | — | — | — | — | — | — | — | — |
| Coverage | ~110–220 sq ft at planting per 5 lb bag | Not listed | Not listed | Not listed | Not listed | Not listed | Not listed | Not listed | Not listed | Not listed | Not listed |
| Price / Size | 5 lb | 10 lb | 15 lb | 20 lb | $32.48 | $30.99 | $17.96 | $24.99 | $14.97 | $37.95 | $14.99 | $35.00 | $19.99 | $18.99 |
| Our Take | The allium specialist with balanced NPK and a 2-phase feeding progr... | — | — | — | — | — | — | — | — | — | — |
Multi-Purpose 10-10-10
Granular with Micros
All Purpose Fertilizer
Tomato & Vegetable
WonderFert All-Purpose
Multi-Purpose Organic
Organic Enriched Veg
Vegetable Food
10-10-10 All Purpose
10-10-10 All-Purpose
Aligned to Allium Growth Cycle
Garlic and onions grow in distinct phases: fall rooting, spring leaf expansion, then bulb formation. This formula feeds the first two phases and steps back for the third — exactly how alliums want to eat.
More Leaves = Bigger Bulbs
Each garlic leaf corresponds to one bulb wrapper. More leaves = more wrappers = bigger, better-protected bulbs. 10% nitrogen fuels the leaf growth that directly determines bulb size.
Balanced P & K for Root & Bulb
10% phosphorus supports fall root establishment. 10% potassium strengthens bulb tissue quality, improves flavor compound development, and extends storage life.
Stop 2–3 Weeks Before Harvest
Critical: cease feeding 2–3 weeks before harvest. Continued nitrogen delays maturity and produces wet bulbs that won't cure properly for long-term storage.
