Perennials: Green Ball Dianthus, 1 by Kaelkitty

Kaelkitty wrote:
Hi All,
I was doing some catch up reading on the Dave's Garden Discussion Forum when I came across the discussion of D. barbatus 'Green Trick' which piqued my interest as I have just purchased this as a small plant (Please NOTE: I live in Australia and can't send you a start due to AQUIS rules here) but the plant would appear to be propagated from stem cuttings as with regular D. caryophyllaceus varieties - I would be trying to root cutting material made from the 2 LOWEST nodes on the purchased stems and laying them horizontally on the rooting medium, first carefully peeling away the mature leaves and applying rooting hormone to the leaf scars as well as the cut node ends - I suspect that if you can keep the cutting from drying out you should get the production of axillary growth from the nodes, which will then form its own root system. The difficulty is in maintaining the health of the original material for sufficient time to produce the required secondary growth. I suggest the oldest nodes because they are the least likely to die off from floral proximity, based on my experience in trying to propagate other D. barbatus varieties.

There is a bit of good growing advice on D. barbatus in general here, especially related to its differences from the longer lived D. caryophyllaceus:
http://www.stevefalcioni.com/2010/12/03/is-it-a-green-trick/

Also there are a few clues online as to which hormones might be required to initiate shoot formation here:

http://www.jstor.org/pss/2441773
http://aob.oxfordjournals.org/content/68/6/563.abstract
and this article is particularly good, if complex.
http://www.pakbs.org/pjbot/PDFs/27(2)/PJB27(2)17.pdf

It should be noticed that all of the above relates to tissue culture, BUT these hormones or their natural analogues do occur in the plants themselves and can be used outside of the tissue culture flask regimen. Your main barrier to success will be the need to achieve and maintain a clean and sterile environment as the introduction of environmental pathogens will accelerate the death of the propagating material which you need to postpone for as long as possible in order to get the shoot production you need. I suggest using clean new vermiculite, new plastic pots, boiled water, dipping all your cutting tools into neat bleach (before and after each cut) and enclosing the dampened pot in a sealed new freezer bag until signs of active growth become apparent, at which time you can CAREFULLY introduce the new plants to the outside world!

I have one final comment. The actual "flower" of D. 'Green Trick' is what is known to botanists as a "Witches Broom". These malformations occur when the growing tissue in the stem of the plant (meristem) divides over and over, giving rise to a mass of tiny shoots where there would normally only be one or a few stems. Witches Brooms are actually more commonly found in woody plants, especially conifers, but can also occur in many other groups of plants including cacti and succulents. Most witches brooms are unstable and eventually die out as they are caused by abnormal hormonal flow in a stem tip due to damage or disease which disappears once the plant overcomes the damage and the flow of the plant's hormones returns to normal. A stable and propagatable mutation such as D. 'Green Trick' only occurs when the actual change becomes permanently part of the cellular nature of the plant.

I hope you will find this information helpful,

Ciao, Kaelkitty.

PS: Here's a photo of my plant - I'll let you know how it goes!