I always enjoy these previews, which give a hint of spring among the autumn colour while still holding on to enough flower buds for their scheduled display in September or October.
One of these is Andromeda polifolia, `Nana Alba' in the Dunedin Botanic Garden's rhododendron dell.
It is not particularly showy, so you might easily walk past it.
However, it is worth stopping to enjoy the combination of small, dark-green leaves covering stiff, wiry stems, which themselves have deep pink new stems and small pure white flowers hanging down in clusters at the end of the shoots.
Belonging to the family Ericaceae, Andromeda flowers are similar to the pendant bells of heath and heather and the plant as a whole has a similar clumping or mat-forming habit, but with less vigour.
Consequently, it combines well with the smaller rhododendrons and other low-growing shrubs. It spreads by suckering and although it is not especially invasive, you do still have to watch out for stray shoots coming up too closely to any prized and vulnerable plants nearby.
• See it in the peat garden by the edge of the Sunken Walk.
• Native to colder parts of the northern hemisphere.
• Grows in peat or sphagnum bogs but still needs well-aerated soil.
• Many slightly different forms, Andromeda polifolia itself has pink flowers.
• Hardy to minus 4degC.
• Propagate by cuttings in late summer.
- Doug Thomson is curator of the rhododendron dell at the Dunedin Botanic Garden.
