Dahlia rooting

Tony Avent Tony@plantdelights.com
Fri, 11 Mar 2011 07:52:57 PST

Back in my flower show days (the late 1970's), I discovered that many cut flower stems could be rooted after the show was over, with dahlias being one of the most successful.  You will need to be sure that there is one vegetative bud on the shoot to be rooted. Since we had our shows in October, I kept them indoors over the first winter, so they could develop a tuber after rooting. I think there are lots of propagation opportunities missed when flower show specimens are discarded.

Tony Avent
Plant Delights Nursery @
Juniper Level Botanic Garden
9241 Sauls Road
Raleigh, North Carolina  27603  USA
Minimum Winter Temps 0-5 F
Maximum Summer Temps 95-105F
USDA Hardiness Zone 7b
email tony@plantdelights.com
website  http://www.plantdelights.com/
phone 919 772-4794
fax  919 772-4752
"I consider every plant hardy until I have killed it myself...at least three times" - Avent

-----Original Message-----
From: pbs-bounces@lists.ibiblio.org [mailto:pbs-bounces@lists.ibiblio.org] On Behalf Of Brian Whyer
Sent: Friday, March 11, 2011 9:09 AM
To: Pacific Bulb Society
Subject: Re: [pbs] Dahlias

It is incorrect to say the cuttings have to form tubers first. Dahlias are flowering without tubers from cutings. They only make tubers around september when days getting shorter.
You are correct of course, I over simplyfied to keep it short, but given a limited amount of nutrients a tuber that has formed roots and shoots may be several weeks ahead of a newly rooted cutting taken from it, that has to form the top growth and a new root and tuber system. It is just the limited nutrients and too many shoots that gives smaller flowers.

I also suggest to take basal cuttings
from the dahlias as clos as you can cut to the roots. This is necessary because stems are hollow, but at the base not.
This also applies to many other herbaceous plants such as named forms of Lupins and Delphiniums, where you need to avoid the hollow stems. It amazed me last summer how quickly a Lupin formed an initial root, in just a few days, although they were just as brittle and difficult to handle as seed grown Lupin roots.

Brian Whyer, Buckinghamshire, England, zone ~8

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