How to plant and care for Hardy Hibiscus

Hibiscus syriacus 'Oiseau Bleu'

🌸 Flower 🔁 Perennial

Large, exotic-looking violet-blue flowers with red eyes from August to October, on a fully hardy shrub. Late to leaf out — do not give up on it in spring!

When to plant and care for it

JanFebMarAprMayJunJulAugSepOctNovDec

Flowers

Prune

Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.

Growing Hardy Hibiscus: what it needs

Light: Full sun · 6+ hours a day
Watering: Water well for the first summer, then in dry spells
Soil: Fertile, well-drained soil
Spacing: 1.5 m
Height: 2–2.5 m
In pots: Only in large containers
Feeding: Balanced feed in spring
Hardiness: USDA zones 5–9

Step by step

On planting day
Plant
Plant at the same depth as it was in its pot, 1.5 m apart, and firm in.
0–1 days after “Plant”
Water In Well
Give a full can of water, then keep moist for the first few weeks while roots establish.
7–14 days after “Water In Well”
Mulch Around the Base
Spread 5 cm of compost or bark around the plant, keeping it off the stems.

Every year

April
Prune
Lightly shorten last year's shoots to keep a good shape; it flowers on new growth.
May
Spring Mulch
Mulch with compost once the soil warms up.
August
In Flower
Exotic flowers — take a photo.