Dahlias have for several years now been beloved of both in season florists and gardeners alike. They have gone from being traditionally known as oversized muppet like creatures in flower shows to them now being bred with the gardener in mind. Their varieties and colours available are at an all time high as Dutch growers compete to raise the most in vogue newly bred varieties for us to fall in love with at home.

The reason I love dahlias is because those that are single flowered, with their butter yellow stamen and anther middles, visibly dripping with nectar and pollen are true pollinator magnets.  Flowering from summer until the first frosts, these dahlias especially will provide a late season nectar bar to our precious bees and butterflies. They might lack the Tim Burton Alice in Wonderland clout that their heavily petalled cousins have but they have more prolific flowering bravado, flowering earlier and much more willingly. The earwigs will also leave them alone thanks to their simpler star burst rather than Marie Antoinette wig like appearances.

The best group to concern oneself with are bishops, which sports the seed grown ‘Bishop’s Children’ one packet of March sown seed will result in a jammy dodger tapestry of deep orange and claret flowers by late July.  There are some exotic new arrivals to the pollinator dahlia class too including the saucer like dancers that are ‘Lou Farman’ and ‘Hawaiian Sunrise’ as if held on bouncing wire stems. The rich coral ‘Waltzing Matilda’ is my top pick for pots.

Dahlias are not carefree plants but once they are understood they can become a true backbone to the gardens summer show and also be a true staple of cut flower harvesting from late July until November. The cutting of their blooms is essential, why dead head when you can live head them for endless vases inside?  It is important to cut their stems always down to a junction of leaves so that the plant is signalled to produce an upsurge of new growth within the week. 

Dahlias do require sun plentifully to flourish, they hail originally from Mexico after all so a sunny spot will see slugs and snails harbour them less. They will grow strongly in ground that is rich, so dig in manure and give them ample space. If the summer is dry, then they will need to water to assist them establishing. On hot days their leaves will look limp but often by the evening they will have perked up again, if they have not then you know they require a good drink.

Dahlias in pots will need watering regardless, every couple of days by midsummer and feeding them weekly will ensure plenty of flowers and healthy-looking foliage. Lining the insides of pots with sheep fleece will help insulate the tubers against the summer heat and also help the compost retain moisture.

Homemade brews of fermented comfrey leaves will smell repugnant, but once diluted into a watering can this will be the best tonic for a dahlia, being rich in nitrogen and potassium.  Bought, seaweed tonic is just as good.

The biggest thing a good dahlia grower can be educated in perhaps though is the nurturing of a dahlias tuber. The tuber is the dahlias powerhouse tuberous root. The tuber is tender thus for dahlias to survive the winter they need some assistance. A tuber readily absorbs moisture, too much of this causes rotting and dismal failure. A typically wet and cold British winter has traditionally seen the lifting of dahlia tubers from the ground as a precaution. This lifting is successful, provided that the tubers are dried out once they have been dug up. Traditionally, you would do this after the first frost which will see the dahlia foliage blacken and die but the tuber underground will still be very much alive. Carefully lift them with a garden fork and then place them somewhere warm, under the kitchen table in my case on newspaper for a good week. The bits of soil can then be brushed off them so that they look very well polished and freshly bought. Feel them for firmness, cutting off any tubers that are squishy.  Once they are fully dry to the touch, I place them in hessian lined boxes and put them in a cold but frost proof place, a spare room or enclosed garage/porch is ideal but not a damp shed as here fungal spores will often ruin them, nor should they be somewhere that is too warm as they’ll shrivel up. By late March it will be time to pot each tuber back up into a 2-litre pot either in the greenhouse or on a windowsill, they’ll be planted outside by mid-May.

The other option that saves all this hassle entirely, is mulching the area where the dahlias grow very generously with a large bucket’s worth of old compost mixed with lots of autumn leaves that is then mole hilled on top of each dahlia very generously. This mulch acts as lovely big insulating but breathable pillow and is used successfully most notably by Sarah Raven who mulches what must be almost a thousand dahlias using this method each winter. By May, the awakening dahlia bursts though the mulch so this method is ideal especially if you have devoted a bed entirely to dahlias which can then be completely mulched over by a good 8 inches.

The winter season of sleeping dahlias should see the task of finding them supporting stakes of coppiced hazel and birch or dried willow rods in readiness for next year. These will then help hold their heavy stems up and protect them against summer storms. Dahlias that are not protected from wind will perish; the stems of curly hazel are especially helpful. Push sticks into the ground firmly encircling the plants well, ensure this task is done before the dahlias begin to flower.