What to Feed Peonies

Peonies should be fed with a balanced liquid fertiliser such as NPK 20-20-20 for overall growth, and a high-phosphorus, high-potassium fertiliser such as NPK 4-18-38 + Calcium & Magnesium during bud stage for stronger blooms and healthier roots.

Why Fertiliser Matters for Peonies

Peonies are long-lived perennials that rely on stored energy in their roots. Each year’s flowers depend on what nutrients were available in the previous season. Without proper feeding, they produce fewer blooms, weaker stems, and smaller flowers. The right fertiliser gives them nitrogen for leaves and stems, phosphorus for roots and buds, and potassium for flower size, colour, and resilience.

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Best Fertilisers to Use for Peonies

Two fertilisers work especially well when used in sequence across the growing season:

CompleteGrow All Purpose NPK 20-20-20: Perfect for early spring feeding, this balanced formula supports shoots, stems, and foliage while building energy reserves.
CompleteGrow Advanced Formula NPK 4-18-38 + CaMg: Higher in phosphorus and potassium, with added calcium and magnesium to prevent deficiencies. Best applied at bud stage and after flowering to boost bloom size, colour richness, and long-term root strength.

Using these two fertilisers together gives peonies exactly what they need at each stage of growth — balanced nutrition early, then bloom-focused support later.

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Seasonal Feeding Schedule

Early Spring: Feed with NPK 20-20-20 as soon as red shoots appear.
Bud Stage (Late Spring): Switch to NPK 4-18-38 + CaMg to support bud swelling and flower strength.
After Flowering (Early Summer): Apply another round of 4-18-38 + CaMg to recharge roots for next year’s blooms.

FAQs on Feeding Peonies

What fertiliser makes peonies bloom? Phosphorus and potassium-rich fertilisers like 4-18-38 + CaMg help trigger bigger, stronger blooms.

Can I just use one fertiliser? A balanced NPK 20-20-20 works well on its own, but combining it with 4-18-38 + CaMg gives the best results.

Do potted peonies need different feeding? Yes — feed every 2–3 weeks in pots, as nutrients wash out faster than in garden soil.

For the best results, feed peonies with CompleteGrow NPK 20-20-20 in early growth and CompleteGrow Advanced NPK 4-18-38 + CaMg at bud stage and after flowering. This routine ensures strong roots, vigorous stems, and abundant, colourful flowers every season.