Tried and True: Tree Dahlias

•Flower from mid to late autumn when few other perennials flower.
• Fill a large space in the garden.
• Many of the best new varieties available here have been bred in New Zealand by our own expert, Dr Keith Hammett.
•Deciduous, so the foliage dies away completely over winter and returns afresh.
• Easy to grow in good conditions which don’t get too dry over summer.

You do need space for these late autumn beauties and they will be badly affected by heavy frosts.


But if you have a suitable position, they are an easy-care delight. These two varieties are both from the breeder, Keith Hammett and alas we no longer have the names. The big, floppy pastel lilac is so pretty against our shed and I thought at first I was looking at a clematis from afar (it is about 2 metres tall). The golden orange sunburst bloom (love the slightly twisted petals) is a little more compact (a little shy of two metres) and has delighted us for a number of years, planted as it is by the mandarin tree whose fruit are colouring to match.

They are not called tree dahlias because they grow up like a tree but rather because they grow much larger than the usual type of perennial dahlias. In windy conditions they need a bit of support – some of ours we fence in with heavy duty bamboo cross bars. Otherwise, they are like any other dahlia with typical hollow stems and dahlia leaves, growing in a large clump from tubers below ground. Most tree dahlias come from D. imperialis which is native to Columbia and Guatemala which explains why they are not keen on cold and frosty conditions.

3 thoughts on “Tried and True: Tree Dahlias

  1. Helen Irvine

    Abby where can I get the orange tree dahlia please? I have the lavender one which gives me the greatest joy May into June.Will do a Google on it.Stunning plant which I cut down as soon as the frosts defoliate it. The stems are so heavy,full of water but such an extreme delight.

    Thank you

    Helen Irvine.Christchurch.

    1. Abbie Jury Post author

      I think Keith Hammett will sell direct – haven’t looked at his website recently but last year there was provision to order on line. From memory, I just googled him and he was easy to find.

  2. Helen Irvine

    Thank you Abby. Took me forever to find a reply so sorry for late acknowledgment. I have been over 40 years in the trade,worn out & crippled now but still doing it,& would like to say that you are the first person on the inter-net commentary circuit that I have found who seems to have a sensible clue. Mary Robinson is good also. Honestly there is so much waffle,hyperbole,airbrushing & I have not a clue how folk today cope without the old well trained folk it was my priviledge to learn from. Keep up the good work.

Comments are closed.