Tree Dahlia

This was my tree dahlia Dahlia imperialis three days ago. I had to wait for a sunny morning to get a good photo with a nice blue sky for the background. Of course blue skies mean frosts and a day later we had the first frost of the season. The leaves up to a height of about 2m are blackened but the flowers appear to have been spared. I remember a huge clump of these growing at the back of the 'new' rose garden at Burnley Horticultural College when I was a student there in the early 1980's. Protected from frosts by neighbouring clumps of bamboo and giant trees they were never frosted. Each pale lilac flower is the size of my hand and luckily for us short people, the flowers hang down so we get a good view looking up at them. There is also a white form which I once saw lining a path outside Cabrini Hospital in town. They looked fantastic!

If you plant this then make sure it is where you want it to be forever. I once dug up the tubers to move them - the clump filled the wheelbarrow - and it was only a five year old plant!