REL_SH said:I want to breed new varieties for cut flowers, but I have a problem with rooting the cuttings. I want to be able to increase the number of certain plants so I can produce more seeds. I tried so many times, with different rooting media- coco peat, perlite, vermiculite, peat moss and perltie, and even in plain water...nothing rooted.
I used 3 different brands of rooting hormones- powder and gel. I spray the cuttings with Physan20 to prevent crown rot, I used propagator, misting, air- conditioned room (low humidity)...Am I missing anything?!
I also tried taking off all of the leaves and leaving some of them on.
Hi Ariel,
It's not obvious to me that you are missing anything. But since you are not having success and my zinnia cutting success rate is about 100%, you must be missing something. I use Premier Pro-Mix with added Perlite as a rooting medium, and I place one cutting per square 3.25-inch pot. I do incorporate the Physan 20 in the water that I moisten the medium with, diluted about one tablespoon per gallon. I place the cutting pots under an 8-inch humidity dome, where they stay 11 to 14 days before their rooting is complete. The humidity domes are under a bank of T8 6500K fluorescent lights, with a timer set for 16 hours of light and 8 hours of dark.
Incidentally, those zinnia branches in the garden that happen to be in contact with the ground will strike roots, much like tomatoes will, in the absence of any rooting hormone. But that is a much slower process than a formal hormone-treated rooting process. Incidentally, I much prefer to use a liquid rooting hormone named Dip 'n Grow, which contains two active ingredients:
Indole-3-butyric acid 1%
1-Napthaleneacetic acid 0.5%
https://www.dipngrow.com/techn...
It looks like your cutting picture may show some internodal tissue on the end. In any case,
it is critical that the cuttings have some internodal tissue at the end, because that is where all of the quick roots emerge.
As you probably already know, you can get only 3 cuttings at best from a zinnia node, which usually limits the number of cuttings you can get from a zinnia plant to maybe 6 to 10 cuttings. A very branched plant might yield more. This is probably not necessary, but I will illustrate the steps in obtaining 3 viable cuttings from a zinnia node.
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Start with a piece of zinnia plant that contains two branches at a node, and remove the leaves from that node. Just tearing them away is fine.
Next, remove the stem below the node and trisect the node so as to share some of the nodal tissue with each cutting end.
Remove all but two leaves from each cutting and place them in rooting medium under humidity domes.
As I mentioned previously, they will have enough roots to support them outside the dome in 11 to 14 days.
Incidentally, after the cuttings develop into branched plants, you can also take cuttings from those. I grow zinnias indoors as well as outdoors, so I can grow them year round. As an experiment, I grew quite a few zinnias from cuttings that were taken from plants that themselves were grown from cuttings. That "second generation" of cuttings had to be grown indoors under lights, but they grew fine. So I had zinnias growing that had originated from a seed that was germinated more than a year previously.
Which raises the question, are zinnias potentially "immortal" ? I know that commercial "fancy" named varieties of Coleus have been grown asexually for many years and many generations from cuttings. I had always supposed that because zinnias were an "annual" that they had some sort of automatic internal death mechanism to kill them in the Fall, but now I have doubts about that.
In any case, you might want to consider commercial asexual propagation techniques, like Tissue Culture. Tissue Culture is not limited by the number of cuttings that you can get from a plant, so it is potentially much more effective than taking cuttings. I will probably renew my zinnia TC experiments when I have the time.
ZM (not associated with any product or vendor mentioned or linked)
