I have two rugosa roses that I did semi hardwood cuttings. They seem to be happy developing callus but no roots. They are bottom heat to 36C, are in perilite and have been treated with num.3 hormone. Should I try to reapply hormone or should I just wait?
Ames 5 rooted under these condition fine.
Johannes,
If the stems are green I would say you are half way to having them rooted. Give them all time they need as long as the stems stay green. You didnāt mention how long they have been rooting but from my experience some roses root really fast and some take much longer. I have had roots form in as little as 14 days and as long as at least 8 weeks. I would not disturb them in any way while they are attempting to create roots and my recommendation is not to add any more rooting hormone.
Good Luck,
bill c.
Itās appeared from what Iāve witnessed over many years that spring weather is very conducive to roots forming from callus. Using the wrapping method, many callused and wouldnāt form roots until in soil out where they received more warmth and increasing light as winter turned to spring them to summer, until the conditions increased to the point of stressing them past their ability to endure.
When I volunteered at The Huntington Library propagating roses, we had very fast successes in the mist propagator out in the sun with heat. As an experiment, I put cuttings in the orchid greenhouse in their mist propagator one winter. Instead of the same varieties rooting within the usual seven to ten day period in the outdoor mister with summer conditions, these all callused and took nearly five months to form roots. The longest was Captain Thomas, which usually rooted quite quickly out doors. Itās impressed me as both genetically as well as weather affected. Even those which propagate quickly, seem to take forever is itās too cool or the light levels are too low. Expose them to increasing heat and light levels and it speeds up their āmetabolismā sufficiently to push roots.
Rugosa is something more toward the genetic end, IMO. As Iāve said, it has often appeared the greater the tendency to sucker, the lower the cooperation rooting. At least thatās what Iāve experienced many times in my climate. Kim
I find rugosas difficult to root.
I agree with Kim- as that has been my experience as well. Although you say youāre providing bottom heat, it may be a photoperiod thing.
Also I found this interesting:
We used our native Salix caroliniana when we did our willow water experiments in 1999. We used a willow water that had already been shown to strongly promote rooting of mung bean (a standard test of root-promoting ability by a substance). We tested the double musk rose (R. moschata) and āFortunianaā, both of which are known to be somewhat finicky about rooting. We compared with a control (no hormone), several concentrations of Dip-n-Grow, and several rooting powders. What we discovered was interesting: As expected, the controls did not root at a very high rate of success. However, the surprising thing was that willow water alone did not increase rooting over the control. The higher concentrations of Dip-n-Grow as well as #3 powder gave excellent rooting, as expected. But when we combined a high-auxin rooting hormone with willow water, we got the best roots of all ā high rates of strike, as well as larger numbers of larger, more branched roots than with the auxin-based hormone alone.
Of course our results might have been different with other rose varieties, but for these two, thatās what happened.
A bit of background on willow water, that is often misunderstood by most rosarians who use it: They assume that it provides auxin, for the same effect as a rooting hormone powder. However, that is not thought to be the mode of action. Rather, it is assumed (but never solidly proven) that to root, a cutting needs adequate amounts of auxin as well as some other substance that has never been elucidated, but which the willow seems to be providing. Plants with plenty of both donāt need any treatment, and their cuttings root easily. Plants that lack adequate auxin will benefit from an applied rooting hormone containing an auxin, but will NOT benefit from willow water alone, since it is thought to provide the other substance but not a significant amount of auxin. Plants that have plenty of auxin but inadequate amounts of the other substance should be stimulated to root by willow water alone. Plants that lack both auxin and the other substance would benefit from treatment with an auxin-based hormone as well as willow water, combined. While this whole concept has not been proven, it does explain the observed results with a good number of plants.
Link: forums2.gardenweb.com/forums/load/rosesant/msg10033815586.html?14