Monday, September 10, 2012

Don't give up....

I played with rooting the flower cluster wood this past spring. One of the Annie Laurie McDowell cuttings callused perfectly, but sat there, doing nothing. I've kept it watered and in partial shade in the 16 oz. foam cup in which it was originally planted. I didn't give up on it and it hasn't given up on me! This is what it looked like this evening. 

It's taken nine months for the callus to generate this brand new basal.

So, when your cuttings remain green, but appear to not being doing anything, take heart. There IS hope!


  1. Hey, Kim. I've been getting into the science of this lately to try my hand at tissue culturing roses. My first attempt was a fungusy failure. Anyway... what you've shown happening here and what happens in tissue culture are very similar. Plant cells are totipotent (I love that word). That means they possess the ability to DEdifferentiate and form callous cells which are like human stem cells in that that can REdifferentiate into whatever cells are needed at the time. Forming callouses is initiated by auxins flowing down the stem and they form the characteristic white knobbly bits we see on calloused cuttings. These are unspecialised cells that don't have a role asigned to them yet. Then a different hormone is needed to initiate the development of shoots and a different hormone again is needed to initiate the development of roots. Talking to David Zlesak, he mentioned that the formation of shoots is the hard bit in tissue culture and not all roses can do it. Getting that instruction to the callous material to get it to make shoots seems to be difficult and it is great to see it happening naturally. This has happened many times to me as well but never on these spent flower stems. Maybe I should survey roses likely to be successful in tissue culture by trying to strike these flower stems with no buds on the understanding that these are the ones that will probably form shoots more easily in the shoot initiation medium. Very Cool!

  2. Thanks Simon! I love it when you come up with the scientific explanation for what it has appeared to be to me all along. Thank you! Yup! Try those pieces we've always been told shouldn't be used because the won't work. Well, guess what? They WORK! I'm of the opinion they may well have more of what's needed than the pieces we usually use. These flowering parts which appear to have no growth buds amaze me with how they suddenly DO have growth buds. Thanks!

  3. Having said that... just this morning I chucked out a pot full of 'Renae' cuttings that included spent flower stems which had failed. The only one that worked was a normal stem with buds. I didn't pre-callous these ones. I just poked them into a pot of potting mix. Normally 'Renae' strikes with ease.

  4. so true! though sometimes it is exasperating! trying to root Aimee Vibert and Hot cocoa, will see...
    Though some roses are much more rooting freiendly than others. Mutabilis did quite a great job with me.
    all the best

  5. Congratulations! I'm glad to hear it. Thanks, you, too.