Petunia Fertilizer
Petunia fertilizer with a bloom-weighted 3-3.6-5.1 NPK, kelp, and eight added minerals — made to keep baskets and beds flowering hard from spring through frost. Phosphorus and potassium lead the ratio to fuel continuous bud set, while high calcium builds the sturdy stems that keep hanging baskets full instead of leggy and bare in the middle.
How to Use Petunia Fertilizer
| Method | Amount | How Often |
|---|---|---|
| Watering can | 2 Tbs (30 mL) per gallon of water | Spring & summer: every 1–2 weeks |
| Watering can | Same dilution | Fall & winter: every 4 weeks |
| Hose end sprayer | Set dial to 1 oz (30 mL) setting | Spring & summer: every 1–2 weeks |
| Leaf misting (optional) | 1 tsp per quart (32 oz) of water | Every 1–2 weeks |
Mix into your normal watering — no separate feeding routine needed.
What's Inside
The 3-3.6-5.1 ratio is built for a plant that flowers nonstop and burns through nutrients doing it. Phosphorus at 3.6% and potassium at 5.1% both outweigh nitrogen at 3%, which keeps energy going into buds rather than foliage — the difference between a basket that blooms all season and one that goes green and leggy by July. All of the nitrogen is nitrate nitrogen, the form roots absorb directly, so response is fast even in containers watered daily.
Beyond NPK: sea kelp (Ascophyllum nodosum) for natural growth compounds, plus calcium at 2.1% — unusually high, and what builds stems strong enough to hold heavy flower loads — magnesium (0.75%), iron, manganese, zinc, boron, and copper. Iron is the one petunias run short of first in containers, showing up as yellowing on new growth while older leaves stay green.
Made For
Every petunia type: hanging baskets, window boxes, patio containers, and in-ground beds — grandiflora, multiflora, wave and spreading varieties, milliflora, and calibrachoa alongside them.
Problems It Solves
- Blooming that slows or stops by midsummer
- Leggy, stretched stems with bare centers in baskets
- Yellowing on new growth while older leaves stay green
- Fewer and smaller flowers as the season goes on
FAQs
How often should I feed my petunias?
Every 1–2 weeks through spring and summer while they're actively blooming, and every 4 weeks in fall and winter for plants kept going in mild climates. Diluting into your regular watering (2 Tbs per gallon) matters most for baskets and containers, which lose nutrients every time they drain.
My petunias stopped blooming by midsummer — will this help?
That's the most common petunia complaint, and it's usually nutrient exhaustion in containers rather than anything wrong with the plant. Daily watering flushes fertilizer out fast. Steady feeding at this ratio, paired with trimming back leggy stems, typically brings baskets back into heavy bloom within a few weeks.
Can I use this on calibrachoa and other basket flowers?
Yes. Calibrachoa, million bells, and most other annual basket flowers have the same heavy-feeding, bloom-forward needs as petunias, and the iron level here helps calibrachoa in particular, which yellow easily in alkaline water. Same dilution across the basket.
Will this burn my plants?
No — at the directed dilution, the formula is designed for regular use through the season. All-nitrate nitrogen and low salt concentration make burn very unlikely. For newly planted baskets still establishing, start at half strength for the first two feedings.
When will I see results?
New growth typically comes in greener within the first couple of weeks, and yellowing from iron shortfall corrects on new leaves. Bloom pickup follows within a few weeks of consistent feeding — fastest on plants that were fading from nutrient exhaustion rather than heat stress.
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