Best Fertiliser for Strawberries in Australia – CompleteGrow Feeding Guide

Strawberries are heavy feeders, and getting the right fertiliser program makes the difference between a weak crop and bowls of sweet, abundant fruit. In Australian conditions, the right mix of nitrogen, phosphorus, potassium, and calcium ensures strong runner growth, healthy leaves, and continuous flowering.

During the early stages, nitrogen drives strong green growth, but as flowers appear, strawberries switch their demand toward potassium and calcium for sweetness, size, and firmness. A balanced NPK ensures that plants do not burn out too quickly while still producing multiple flushes of fruit across the season.

Australian climates—from warm QLD winters to the cool frosts of Victoria and Tasmania—mean fertiliser timing is just as important as the blend you choose. Feeding schedules must adapt to seasonal conditions for consistent yields year after year.

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How and When to Fertilise Strawberries

Planting Stage (Late Winter – Early Spring): Apply a balanced fertiliser such as CompleteGrow All Purpose Liquid NPK 20-20-20. This supports leaf canopy and root establishment.
Pre-Flowering (Mid-Spring): Switch to CompleteGrow Advanced Formula NPK 4-18-38 + CaMg. The high phosphorus and calcium content encourages flower initiation and improves fruit set.
Fruiting & Harvest (Summer): Maintain fortnightly feeding with CompleteGrow NPK 4-18-38. Potassium at this stage maximises sugar levels, giving strawberries their sweet, rich flavour.
Runner Production (Late Summer – Autumn): Reduce feeding slightly to avoid overly leafy plants. A lighter application of NPK 20-20-20 keeps runners strong for next season’s crop.

In pots or hydroponic systems, fertiliser uptake is faster, so feed in smaller but more frequent doses. Always water after feeding to protect shallow strawberry roots from fertiliser burn.

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Fertiliser Problems and FAQs

Even with the right fertiliser, strawberries can show signs of stress if nutrients are mismanaged. Here’s how to spot and fix issues:

Excess Nitrogen: Produces lush leaves but poor fruit. Switch to a potassium-rich formula immediately.
Yellowing Between Veins: Often magnesium deficiency. Supplement with CompleteGrow Cal-Mag Hydroponic Nutrients.
Small, Sour Berries: Insufficient potassium during fruiting. Boost with NPK 4-18-38.

FAQs

What fertiliser makes strawberries sweeter? A potassium-rich formula like NPK 4-18-38 during fruiting enhances sugar accumulation.
Can I over-fertilise strawberries? Yes—too much nitrogen delays fruiting and weakens flavour. Always follow a feeding schedule.
Do strawberries need calcium? Absolutely. Calcium prevents soft fruit and helps berries store longer after picking.
How often should I fertilise strawberries in pots? Every 10–14 days during fruiting, as nutrients wash out faster than in garden beds.
What is the best CompleteGrow product for strawberries? Use CompleteGrow Advanced Formula NPK 4-18-38 + CaMg as the primary feed, supported by NPK 20-20-20 early on.