Bulb Fertilizer for Tulips, Daffodils & Iris

When your flowering bulbs may benefit from feeding

During the active growing season, when new shoots, leaves, flowers or fruit are forming
When plants have been growing in the same bed or container for several seasons
After heavy rain or frequent irrigation, which can carry nutrients below the root zone
For plants in containers, raised beds or sandy soils that hold few nutrients
As buds form and through the flowering period, when demand is highest

Plant appearance can also be affected by light, watering, roots, temperature, and other growing conditions, so feeding is one part of overall plant care.

Results you can see

Feeds foliage for deeper color and a brighter, more lively look.

Encourages fresh leaf and stem growth for a fuller, thriving plant.

Supports healthy, resilient roots that absorb nutrients more effectively.

Works for flowering bulbs

Tulips
Daffodils
Iris
Crocus
Hyacinths
Alliums
Lilies
Gladiolus

How to use

Watering can — bulbs under 6 inches

1 Tbs (15 mL) per gallon of water

Feed once weekly through the growing season
Watering can — bulbs over 6 inches

2 Tbs (30 mL) per gallon of water

Feed once weekly through the growing season
Hose end sprayer

Set dial to above feedrates

Weekly through the growing season
Leaf misting (optional)

1 tsp per quart (32 oz) of water

Every 1–2 weeks

What's inside

The 3-3.6-5.1 ratio is built for a plant that has to flower and refuel in one season. Phosphorus at 3.6% and potassium at 5.1% both outweigh nitrogen at 3%, directing energy into blooms and into rebuilding your bulb after flowering rather than into excess foliage. All of the nitrogen is nitrate nitrogen, the form roots absorb directly, so response is fast and burn risk stays low around tender bulb roots.

Beyond NPK: sea kelp (Ascophyllum nodosum) for natural growth compounds, plus calcium at 2.1% — unusually high, and what builds sturdy stems that hold blooms upright — magnesium (0.75%), iron, boron, copper, manganese, and zinc. Potassium in particular is what a bulb draws on to recharge for next year, which is why feeding continues after the flowers fade, not just before.

Frequently asked questions

How often should I feed my bulbs?

Bulb Fertilizer is built for a plant that has to flower and refuel in one season, so it’s meant for steady weekly feeding rather than a single dose at bloom. Feed once a week through the growing season at 1 tablespoon per gallon of water for bulbs under 6 inches and 2 tablespoons per gallon for larger bulbs. The weeks during and after bloom matter most; that is when your bulb rebuilds its reserves for next year, and the potassium-led formula supports that recharge.

Should I keep feeding after the flowers fade?

Yes. This is the most important window. After blooming, your bulb pulls energy back down through its leaves to recharge for next season, and potassium is the nutrient it draws on most to do it, which is why Bulb Fertilizer carries potassium at 5.1%, above both nitrogen and phosphorus. Keep feeding weekly until the foliage yellows on its own, and leave the leaves in place until then; they’re the bulb’s way of storing up for a stronger return.

When should I start feeding?

Begin as growth emerges: early spring for spring bloomers like tulips and daffodils, and at planting or sprouting for summer bulbs like dahlias and gladiolus. Bulb Fertilizer is formulated for the whole growing season, not just the weeks before bloom, because the phosphorus supports the flowers you’ll see this year while the potassium and calcium build your bulb and stems for the following one. Feed weekly from first growth until the foliage yellows naturally.

Will this burn my bulbs?

Bulb Fertilizer is a dilute liquid feed, and dilution is what matters here. Fertilizer burn happens when concentrated salts sit against the roots: too much product in too little water, or granules piled at the base of a plant. All of the nitrogen in the formula is nitrate nitrogen, which roots absorb directly, and mixed at 1 or 2 tablespoons per gallon by bulb size and applied weekly, the nutrients arrive in solution at a strength tender bulb roots take up as they water. Newly planted bulbs can go straight onto the standard rate.

Can I use it on dahlias, lilies, and amaryllis?

Yes. Bulb Fertilizer is formulated for every flowering bulb, and summer bulbs and tubers like dahlias, lilies, gladiolus and amaryllis follow the same bloom-and-recharge cycle as spring bulbs: flower, then rebuild through the leaves for next year. Feed them weekly through their growing season at the rate for their size, 1 tablespoon per gallon under 6 inches and 2 tablespoons per gallon above, until the foliage begins to yellow.

When will I see results?

Stem strength and bloom quality show in the current season’s flowers. Bulb Fertilizer carries calcium at 2.1%, which supports the sturdy stems that hold blooms upright, and phosphorus at 3.6% supports the flowers themselves. The bigger payoff comes the following year: bulbs fed weekly through and after bloom store more energy in their reserves, so they return in flower instead of fading out.

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