How to Make Hydrangeas Pink in Australia

Hydrangeas turn pink when grown in neutral to alkaline soils, where aluminium is locked away and cannot be absorbed by the plant. Fertiliser choice, soil amendments, and seasonal care all play a role in keeping blooms bright pink.

Soil pH above 7: Produces pink to red flowers.
Low aluminium availability: Alkaline soils prevent blue pigments from forming.
Fertiliser choice: Balanced fertilisers with higher phosphorus (such as CompleteGrow NPK 20-20-20) reduce aluminium uptake, supporting pink tones.

In Australia, mophead and lacecap hydrangeas (Hydrangea macrophylla) respond most strongly to pink colour changes, while white hydrangeas remain white regardless of soil adjustments.

508558000_18505424920023229_8824081539905442017_n (1) (1)

499685593_1658036024848603_1290802774878414569_n

Steps to Turn Hydrangeas Pink

Changing hydrangeas from blue or purple to pink is a gradual process, usually taking one to two flowering seasons. Follow these steps:

Test Soil pH: Use a garden pH kit. Aim for a pH between 7.0 and 7.5.
Add Lime: Apply garden lime or dolomite regularly to raise soil pH. Reapply every 2–3 months to maintain alkalinity.
Choose the Right Fertiliser: Use a balanced fertiliser such as CompleteGrow NPK 20-20-20. High phosphorus prevents aluminium absorption, encouraging pink blooms.
Improve Soil Structure: Add composted mulch or straw to buffer pH and support healthy root systems.
Control Water Source: Avoid acidic rainwater if aiming for pink—use tap water where slightly alkaline.

Container-grown hydrangeas are easier to keep pink since potting mix can be adjusted more precisely than garden soil.

436545893_432293049554878_7821749524444943650_n (1)

499452081_1242269020806884_2516915376820635177_n

Tips, Mistakes & FAQ

Tips to Maintain Pink Blooms

Check pH regularly—soils naturally drift back toward neutral or acidic.
Fertilise consistently with CompleteGrow NPK 20-20-20 to reduce aluminium uptake.
Mulch with neutral materials like straw or sugarcane, not pine needles (which acidify).
Be patient—strong pink colour may take 12–18 months to stabilise.

FAQ

Q: Can all hydrangeas turn pink? A: No. Only coloured varieties (mophead and lacecap) respond. White hydrangeas stay white.
Q: How often should I add lime? A: Every 2–3 months, but always test soil pH first to avoid over-alkalising.
Q: Does fertiliser alone make hydrangeas pink? A: No—fertiliser supports plant health, but soil alkalinity is the main factor.
Q: How long does it take to change colour? A: Usually one full season, sometimes up to two for deep colour shifts.

Final Recommendation: To achieve vibrant pink hydrangeas in Australia, maintain alkaline soil using lime, and fertilise regularly with CompleteGrow NPK 20-20-20. With steady care, blooms shift from blue or purple to soft pink and eventually deep rose shades.