Gardening column: Show of colour even beginners can make bloom

Dahlias will bloom all summer.
Dahlias will bloom all summer.

As one of the most freely planted of all the perennial summer bedding, dahlias will give a colourful show even in the hands of the not-so-green-fingered gardener.

They produce masses of blooms until the first frosts, then the tubers are lifted and stored frost-free ready to do the same thing the following year.

It’s too early to plant them direct into the ground just yet as they are frost sensitive but can be started into growth now, planted up in boxes of moist compost and either in a greenhouse or indoors.

Once potted up, shoots will soon appear and these can be left to grow in good light so that they are not drawn.

If facilities are available, some of these shoots can be removed and treated as cuttings as they will go on to produce a better plant.

But for general garden display this is not essential as a good show is still achievable by just leaving the shoots produced by each clutch of tubers.

Of course tubers can be planted outside but not until late May as by then frosty nights will be over.

Tubers are available now in all the various types from the dainty golf ball-headed pompons to the decoratives and the ‘spiky’ cactus blooms, as well as the collerettes with their outer ring of flat ray florets plus an inner ring of collar florets and central group of disc florets, and the single-flowered bedding varieties.

With disbudding and feeding the showmen produce the decoratives with heads the size of soup plates but this is a very specialised way of growing dahlias and not for the general grower. For the floral art enthusiast, the collerette and pompon varieties are much in demand.

Dahlias are gross feeders, require constant watering in dry spells and regular removal of spent flowers, and will reward this TLC with a spectacular show.

Even though outside planting is several weeks away, the bed can be prepared now by digging in plenty of humus-rich organic matter such as well rotted farmyard manure or garden compost.

When the time does come to plant out it is essential that a stake is in place once the hole has been dug. To do this following planting can result in damaging unseen tubers below ground.