Best Annual Flower Fertilizer (15-30-15): Maximum Phosphorus Bloom Booster for Non-Stop Color All Season Buy on Old Cobblers Farm
Old Cobblers Farm™ Wicked Growth Annual Flowers Fertilizer
by Wicked Growth — Littleton, NH
30% Phosphorus — Maximum Bloom Power
Double the phosphorus of any balanced formula and triple the P of most garden fertilizers. Phosphorus drives flower bud initiation, petal count, and continuous rebloom.
Vivid, Saturated Color
Phosphorus fuels the biochemical pathways that produce intense flower pigmentation — deeper reds, brighter yellows, richer purples, and more vivid pinks.
15% N + 15% K Support
Balanced nitrogen maintains healthy green foliage without pushing leggy growth, while potassium strengthens stems and improves heat and drought tolerance.
480 Pots Per Bag
At 1 tsp per 6" pot, one 5 lb bag feeds approximately 480 individual containers per application. For beds, covers ~160 sq ft.
Every 3–4 Weeks
Annuals are heavy feeders that deplete nutrients quickly. Reapply every 3–4 weeks through bloom season for uninterrupted flower production.
Dissolves for Liquid Feeding
Can be dissolved in water for container drenching and hanging basket feeding. Versatile application for beds and pots alike.
All Annual Varieties
Petunias, marigolds, zinnias, impatiens, begonias, snapdragons, cosmos, dahlias, geraniums — every annual flower benefits from high-P feeding.
Trusted by 20,000+ Growers
Developed in Littleton, New Hampshire. Sold nationwide on Amazon, Walmart, eBay, and theoldcobblersfarm.com.
| NPK Ratio | 15-30-15 |
| Derived From | Urea, Monoammonium Phosphate, Muriate of Potash |
| Item Form | Granular |
| Release Speed | Quick-release |
| Application Rate | 1 tbsp / sq ft (beds) | 1 tsp / 6" pot |
| Method | Broadcast, incorporate, or dissolve |
| Frequency | Every 3–4 weeks during bloom season |
| Sizes | 5 lb | 10 lb | 15 lb | 20 lb |
| Supports | Petunias, marigolds, zinnias, impatiens, begonias, snapdragons, cosmos, dahlias, celosia, geraniums, all annuals |
| Setups | Flower beds, containers, window boxes, hanging baskets, borders, mass plantings |
| Feature | Old Cobblers Farm™ Wicked Growth Annual Flowers Fertilizer | Bloom Booster Flower Food | Blossom Booster | Smart-Release Flower/Veg | Ultra Green All Purpose | Super Bloom | Bloom Booster | Flower Plant Food | All Purpose Food | Flower & Rose Granular | Big Bloom |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NPK | 15-30-15 | 10-52-10 | 10-30-20 | 14-14-14 | 10-10-10 | 12-55-6 | 10-52-10 | 10-10-10 | 4-4-2004 | 3-5-2004 | 0-0.5-0.7 |
| Phosphorus | 30.0% | 52.0% | 30.0% | 14.0% | 10.0% | 55.0% | 52.0% | 10.0% | 4.0% | 5.0% | 0.5% |
| Potassium | 15.0% | 10.0% | 20.0% | 14.0% | 10.0% | 6.0% | 10.0% | 10.0% | 4.0% | 4.0% | 0.7% |
| Form | Granular | ||||||||||
| Sizes | 5 lb | 10 lb | 15 lb | 20 lb | 1.5 lb | 1.5 lb | 4.5 lb | 5 lb | 2 lb | 1.5 lb | 8 lb | 4 lb | 4 lb | 32 oz |
| Release Speed | Quick-release |
Bloom Booster Flower Food
Blossom Booster
Smart-Release Flower/Veg
Ultra Green All Purpose
Super Bloom
Bloom Booster
Flower Plant Food
All Purpose Food
Flower & Rose Granular
Big Bloom
30% Phosphorus — Maximum Bloom Power
Double the phosphorus of any balanced formula and triple the P of most garden fertilizers. Phosphorus drives flower bud initiation, petal count, and continuous rebloom.
Vivid, Saturated Color
Phosphorus fuels the biochemical pathways that produce intense flower pigmentation — deeper reds, brighter yellows, richer purples, and more vivid pinks.
15% N + 15% K Support
Balanced nitrogen maintains healthy green foliage without pushing leggy growth, while potassium strengthens stems and improves heat and drought tolerance.
480 Pots Per Bag
At 1 tsp per 6" pot, one 5 lb bag feeds approximately 480 individual containers per application. For beds, covers ~160 sq ft.
