Dahlias will grow well in sunny locations when planted in good free draining soils and sheltered from the prevailing winds.
However, it is good practice to stake the taller varieties; some can be grown successfully in suitably sized containers as well. With regular deadheading they will flower from mid-summer right through to autumn, giving a splash of colour and an impressive late autumn display.
They need to be cut back to ground level and removed after the first frost hits them as the stems, being very fleshy, will blacken, collapse and allow unwanted pathogens to establish. Dahlias have underground tubers prone to rotting especially when dormant over the winter. The tubers can be lifted and stored in damp sand during this time, which will give you a chance to divide them to plant back in the garden in mid-spring or to give away.
The dahlia photographed for this article is one of the most popular dahlias in our collection: many visitors stop to ask what it is. Dahlia ‘Longwood Dainty’ was bred here in New Zealand in 1986 by the late Mr Jim Robbie and was named after the Longwood Ranges close to where Mr Robbie lived in Riverton, Southland.
This dahlia can be seen flowering along the edge of the long border in the herbaceous collection.
Garden Life is produced by the Dunedin Botanic Garden. For further information contact Linda Hellyer.
