Cultivation of dahlias

The dahlia likes all soils if they are not too chalky. However, it prefers a humus-rich soil in a sunny position. The soil should be prepared in the Autumn. It should be enriched with decomposted manure or a phosphorus - potassium fertiliser. The dahlia loves potassium (it can be found in wood-ash).

Planting :

It should be carried out at the end of March until the end of April depending on where you live. The tubers or root parts are planted 10 cm deep. Leave a space of 1 metre between the plants for the large varieties, 70 cm for medium and 50 cm for dwarf varieties and put in supports. Water but not to excess.
Plants propogated from cuttings should be planted 5 cm deep when frosts have finished. Put in supports. Water copiously until their recovery.

Watering :

The dahlia likes water but only when it has developped. Avoid overwatering during planting of the root parts, as this encourages gastropods who love the young plants.

Pinching out :

This technique is not practised by everyone. It consists of removing the head of the plant when a dozen or so leaves have formed. This allows the plant to branch out and produce more flowers. Staking is indispensible because the stems become fragile and more easily break...

Bud removal :

If you want quality flowers for a bouquet or exhibiting then use bud removal (except for pompon and dwarf varieties). This consists of removing the buds and lateral shoots on two or three series of leaves below the terminal bud. You can obtain large flowers on very long stems like those you can see in the exhibition at The International Potato Festival.

Remove fading flowers where their stalk meets the main stem, this will allow the plant maximum energy.

Over Wintering :

Towards the end of October, or when the dahlias have blackened after a light frost, cut the stems to 15 cm. During a dry period dig-up the root parts, wipe them and leave to dry for several hours on the ground.
Put them in a cellar or a place where the temperature can be maintained between 0 °and 8°. Be careful, because if it's too damp the root parts will rot, too dry and the tubers will become parched! If you don't have a place that meets this criteria then you can store them in a mix of well-dried peat.