This is the pure white form of Dahlia imperialis and accordingly is one of the tallest varieties that we offer growing up to 10 ft in the UK. It is a late flowering single flowered variety with flowers of pure white. Dahlias like dahlia imperialis Alba like to be planted into warm soil which has been well manured the year before. Protect the young shoots of dahlia imperialis Alba from slug and pest damage.
Remember to stake these!
Plant Indoors: The Dahlia tubers of Imperialis can be started off indoors from January to March. Plant them out into the garden or containers after the fear of frost has passed. This is normally towards the end of April but can be earlier in the south and in coastal areas.
Plant Outside: Alternatively plant direct into the garden when the soil has warmed up and the fear of all frosts have passed. Cultivate soils to a depth of 20cms and plant tubers so that the top of the tuber is 5cms below the soil surface. Soils are best manured in the winter before planting as the young roots of dahlias do not like fresh manure around them.
Our Tip: Dahlias can be left out over winter in well drained soils, just mulch to give added protection.
Remove dead flower heads to ensure a summer of flowers and remember to feed during the leaf and flower stage with something like bone meal or tomato feed.
Will benefit from being started off early in a greenhouse or similar:
Remove dead heads as they appear to encourage further flowers
Flowering Height: 8-10 feet (240-300cm)
Flowering Period: July to first frosts.
Soil type: Free draining humus rich soils, in heavier soils add grit to help with drainage.
Aspect: Semi shade to full sun.
Planting Depth: 10-15cm
Planting Distance: 1m
For further growing advice visit Tims tips/dahlias on you tube.