Dahlias are daring and different

This week we’ll focus on the tallest versions of this plant, which grows from a tuberous root and belongs to the Asteraceae family. Although there are 30 species of dahlia available (originating from Colombia and Central America, where the Aztecs used the plant for medicinal purposes and even fed on the petals), many varieties of hybrids and cultivars occur around the world today.

The tallest of these are the Cactus (80cm-1m), Decorative (80cm-1m) and Dinner Plate (1.5m-2m) dahlias. The Dinner Plates are not just tall; their flowers can be as massive as 25cm in diameter. And the Decoratives offer even more than you bargain for by popping up in double bloom, while the Cactus varieties, on the other hand, are known to have narrow, spiky florets.

To make the most of these tall varieties, train them to flower as best they can by pinching and disbudding them. When the stems are almost at their tallest, nip off the soft tip of the main shoot to encourage it to bush out and produce additional leaves, which allow for more photosynthesis to occur, resulting in larger flowers.

For tall red options, look for the following Cactus cultivars: Alva’s Doris, Cheerio, Forrestal, Ma Jolie Sure Thing .

However, if you prefer yellow and orange blooms, go for: Einzi, Mev. Cl. Andries, Preference, Wagschats Goldkrone .

For more of a show, look to these Decorative hybrids with their double blooms: Snow Country is as white as the name suggests, with a light-yellow centre; the lilac Nepos has a white base; and Edinburgh’s white tips offset its gorgeous purple petals.

But if it’s size you’re after, go all out with these Dinner Plate options: Lavender Perfection (fuschia), Red Dinner Plate (signal red) and Kelvin’s Floodlight (light yellow).

As summer plants, dahlias love the sun, and want lots of it too. A spot that receives some shade at midday means the plant won’t be as thirsty, but, no matter where it is planted, it needs a lot of water – but be sure that your soil is well-draining.

And, most importantly, give them their space to shine by not planting anything taller in front of them. – Hadeco.