Azalea Flowering Time

Azalea Flowering Months and Temperature

The azalea (Rhododendron simsii) does most of its blooming between late winter and spring, which falls around July to September in the Southern Hemisphere. The flowers come in dense clusters and can be pink, red, white, or bicolor. What actually sets the buds going is a stretch of cool nights between 7 and 15 °C lasting several weeks. That cold spell tells the plant to stop putting out leaves and switch over to forming flowers.

The substrate has to be acidic, with pH between 5 and 6. A blend of peat moss, garden soil, and pine bark works well. Do your pruning right after the plant finishes flowering, since that shapes it and pushes out new branches that will hold next season's buds. Prune at any other point in the year and you cut off the flower structures while they're still forming.

Applications

It comes in handy for ornamental gardens, public squares, hedges, vase cultivation, and bonsai work. Mountain regions and the milder subtropical climates where nights drop off are where azaleas do best. You can also use it to lay out a planting calendar or to line up the blooming peak with a seasonal event.

FAQ

Why won't my azalea bloom? Nine times out of ten it's because the nights stay too warm, above 18 °C all year, or because someone pruned it outside the post-flowering window and took the buds off with it.

Can I grow azalea in a pot? You can. Use an acidic substrate, water it with non-chlorinated or rainwater, and keep it in partial shade or under filtered morning sun.

How long does the flowering last? Figure on 4 to 8 weeks, give or take, depending on the cultivar and how warm the air is. Cooler temperatures stretch the show out longer.