Hibiscus syriacus (syn. 'Blue Bird') 'OISEAU BLEU' rose-of-Sharon

This Rose-of-Sharon variety has a French name Oiseau Bleu which was difficult enough to be replaced with an English translation Blue Bird. It had long been the only blue variety in trade until Marina (BLUE SATIN™) appeared in 1996, and in 2007 a much deeper blue variety from France named ULTRAMARINE® took its place. However, Blue Bird is still very demanded for its attractive, pastel lavender blue flowers that are about 6-8 cm across and decorated with a large maroon eye in the centre. It looks great both on its own, or combined with other varieties of contrasting flower colours(s). Flowers come out in profusion in early July and don’t stop blooming until all buds have gone - sometimes by mid or late September. The plant grows into a densely branched, upright shrub.

It has very decorative leaves that are unique. They are deeply lobed, palmate, mid to dark green and coarsely toothed. If they turn yellow in summer the plant manifests too much water at the roots. They are either over-watered or planted in too heavy soil where it has not established yet.

Pruning is an issue that always gets me started here. Hard pruning leads to larger flowers, that's true, but also production of long, immature, flexible twigs. The only cut I recommend is to rejuvenate old plans - prune it hard in early spring by 50-75% and let it grow for another 10 years or so.

Rose-of-Sharon is quite adaptable of soil type. It likes sufficient moisture and but you cannot transplant it into standing water. When fully established it will love occasional flooding in summer. Older plants dislike peat. Selective fertilizers for better flowering are convenient but not crucial. Place it in full sun only. Fully hardy to min. -27°C (USDA zone 5). Not suitable for pots.

Last update 10-06-2007; 08-03-2021