Growing dahlias

As you get older, some plants which you used to think of as boring, old-fashioned, suddenly become much more interesting. One such plant is the dahlia. There are many forms of dahlia flower (cactus, pom-pom, paeony, colerette, water lilly..... ) and you can grow them from seed, tubers or cuttings. Within each flower type there are small, miniature and giant plant types.

Growing from seed simply to fill a border is cheap and easy, and you can get some excellent flowers. But you will also get a few off types, and you wont have much control over size. You need to grow them under some protection and don't plant them out until all danger of frost has passed. Don't start them too early as they are fast developers, and before you know it, you can have quite large plants, too big for the greenhouse, but not hardy enough to plant out.... one of the many challenges of growing dahlias!

If you want to grow them for showing, then generally, tubers and cuttings are the best way, purchased by mail order from specialist suppliers such as Halls of Heddon in Northumberland or
the National Dahlia collection. Generally these are the best way to get large, showy plants which have been selected by breeders and will grow true to form each time.

Order tubers any time from now (November). Cuttings can be ordered in the spring, but probably won't be delivered until May when the danger of hard frosts has passed. However cuttings which are delivered in early summer may not give you blooms for showing in early September if it happens to be a cool summer.

The images shown in this article include four varieties purchased as cuttings last year and grown in St Ives; the varieties being Kathryn's cupid (pink pom-pom) and Fiona Stewart (white pom pom) in the background, and El Cid (yellow water lilly) and Crystall Ann (yellow/orange cactus) in the foreground. For interest, the smaller flowers dotted around them are Helichrysum.

In order to show dahlias, you need generally three or five stems in a vase (read the schedule carefully for the exact number!) with only one flower per stem and a small amount of leaf left attached to the stem. Note that when dahlias grow they produce three flower buds per stem. So to get the biggest blooms (and ones 'according to schedule' for showing) they need two of the three buds pinching out. If you want to know more about how a dedicated dahlia grower does it, take a look at this video by clicking here.

Now that is dedication!

I hope this has inspired you and we see some more dahlias entered in the Flower and Produce Show in September 2012.