Fertilizer for Chrysanthemums: NPK Guide and Application Rates
Chrysanthemums (mums) are responsive to fertilization and produce their best fall displays with consistent feeding throughout the growing season. The University of Minnesota Extension recommends starting fertilization when new growth appears in spring and continuing through August, then switching to a bloom-boosting formula as buds form. Stop all fertilizer once blooming begins to avoid soft growth heading into winter.
Quick Reference
What NPK Ratio is Best for Chrysanthemums?
The recommended NPK ratio for chrysanthemums is 5-10-10. The phosphorus-heavy 5-10-10 ratio supports strong root systems and flower/fruit production in chrysanthemums.
Chrysanthemums NPK needs shift at each growth stage. Balanced formula for early spring growth and transplants during the Seedling phase, then high phosphorus and potassium for abundant fall blooms once flowering begins.
NPK by Growth Stage for Chrysanthemums
| 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 formula for early spring growth and transplants |
| Vegetative | 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 feeding during active growth and pinching period |
| 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 | High phosphorus and potassium for abundant fall blooms |
| 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 | No fertilizer after bloom; prepare for dormancy |
When Should You Fertilize Chrysanthemums?
In zone 4, start fertilizing chrysanthemums in May. In zone 9, begin as early as March. Apply every 3 weeks through the growing season.
Which Zones Can Grow Chrysanthemums?
Chrysanthemums grows in USDA zones 4 through 9, spanning a 6-zone range.
Fertilization Start by Zone
| Zone | Start Month |
|---|---|
| Zone 4 | May |
| Zone 5 | May |
| Zone 6 | April |
| Zone 7 | April |
| Zone 8 | March |
| Zone 9 | March |
What Are the Best Fertilizer Products for Chrysanthemums?
Look for products with an NPK close to 5-10-10. Espoma Flower-tone is the most popular choice among home gardeners for chrysanthemums.
- Espoma Flower-tone
- Miracle-Gro Bloom Booster
- 5-10-10
Prices vary by retailer and region. Check current pricing before purchasing.
Container and Raised Bed Adjustments for Chrysanthemums
Excellent container plants; feed every 2 weeks with liquid bloom fertilizer through September
Common Fertilizing Mistakes with Chrysanthemums
- Treating fall potted mums as perennials without proper fertilization; they need consistent feeding to return.
- Continuing nitrogen-heavy feeding into fall, which produces soft growth that winterkills.
- Not pinching plants back during summer, resulting in leggy stems with fewer blooms.
- Over-watering potted mums, causing root rot that mimics nutrient deficiency symptoms.
Tips for Fertilizing Chrysanthemums
- Begin feeding in early spring when new shoots emerge from the crown, continuing through August.
- Switch to a high-phosphorus fertilizer (5-10-10) once flower buds are visible in late summer.
- Pinch growing tips until mid-July to promote bushier plants with more bloom sites.
- Garden mums overwintered in the ground need spring and summer feeding; potted fall mums are short-term.
Organic Fertilizer Alternatives for Chrysanthemums
Sources
Source:Clemson University ExtensionLast updated: