Before planting, young plants should be watered well and then laid out alongside their appropriate canes.
A hole is taken out by the cane slightly larger than the root ball and the plant set in so that when filled in, the surface of the soil will form a depression around the stem.
This is to ensure that any water which is applied can soak down to the roots and not run away. The plant should be tied to its cane and labelled.
If soil conditions are very dry, then some water can be given to enable the plant to become established, otherwise it is better to encourage young plants to seek out any water in the lower soil levels. The depth of planting is not critical, but some cultivars of giant and large types benefit from lower planting, in which case the lower pair of leaves is removed and the next pair of leaves is set at ground level.
Newly planted young plants are a great attraction to slugs and snails which can decimate a dahlia bed overnight. It is essential to protect against damage by using slug pellets immediately after planting. At planting time, colonies of aphids can rapidly develop on the tips of plants and it is advisable to give a precautionary spray with a systemic insecticide.