7 Jun 2006
SUGGESTIONS FOR HOW TO ASEXUALLY PROPAGATE ROSES
Joel Ross, MD
#1 Pre-prepare miniature greenhouse enclosures from empty 2 liter clear soda bottles whose bottoms have been cut off and whose screw caps have been discarded. The greenhouse will be placed over the cutting in a 1 gallon black can after the cane has been prepared and placed in the planting medium (described below). The greenhouse will create the proper humidity necessary for the cuttings survival.
#2 Pre-prepare planting medium using well blended 50% commercial seed starter mix and 50% Perlite OR alternately 100% horticultural sand. Fill 1 gallon black cans 3/4 full of the potting mix (blend or sand) add 1/2- 1 oz mycorrhizae and blend (stir) well again. Wet the resulting mixture thoroughly with water to which you have added a liquid root stimultor (eg Greenlite Root Stimulator),
HOW TO CHOOSE YOUR MIX:
1) For single specimen/single can the choice is based upon personal preference and past results.
2) For multiple cuttings/single pot (in order to eliminate wasted effort because a growth failures), Ivey Bodin believes sand offers an advantage at harvest because it provides a means by which you can more readily separate entwined plant roots without tearing them. Usually a planter of large size (trough of 2-3 feet in length) is planted with dozens of cuttings under some sort of airtight cover which substitutes for the simple greenhouse described above. Failed cuttings are pulled out. The sand is gently washed away from the roots with a stream of water when the plants are mature enough for the first tranplanting. However, Charlie Thurston routinely starts multiple cuttings in a single can no matter what the potting medium and deals with root separation at translpant time by teasing the plants apart "as gently"as possible.
CAUTION: DO NOT USE ANY POTTING MIX FOR A SECOND TIME BECAUSE IT BECOMES CONTAMINATED WITH BACTERIA WHICH ARE LIKELY TO DIMINISH THE CHANCE OF THE SECOND ROUND CUTTING'S SURVIVAL.
#3 Select good stout disease free canes with 5 or 6 budeyes on them. Use hardwood that is part of a cane which has just finished blooming (because the budeyes are hormonally primed to begin their development). Cut off the bloom. Save the thorns (which act as underground "anchors" ). Save the leaves on the top 3 budeyes (to provide nutrition to the growing plant). Remove the leaves from the remaining lower budeyes (which will be shoved underground to develop into roots). #4 There are several ways to encourage successful root formation:
a) Phil Ash recommends that the portion of the cane to be pushed under ground contain a dog leg (cane looks like this ^ when held upright) because this structure contains multiple potential bud eyes which are activated to form roots.
b) John Bagnasco recommends cutting that portion of the cane to be shoved underground vertically down the middle of the white pith (xylem) as this does not injure the superficial budeyes and does provide increased surface area from which roots will develop. Practice this a few times with canes that are of no consequence in order to improve your skill level for the "real thing".
#5 Regardless of whether you choose the a or b option above, dip and thoroughly coat that portion of the cane (including the budeyes) to go underground in a rooting solution. I prefer a viscous solution over a powder since I believe it attaches to the cane surface better. Push the specimen into the potting medium to cover the budeyes and cane area destined to become roots. Firm the soil around the cane to keep upright and engage the underground thorn "anchors". Place the greenhouse over the specimen taking care not to damage the remaining leaves and push firmly undergound (1/2 inch) to create a closed system. Water potting medium thoroughly with water containing root stimulator again (and daily thereafter for 3-5 days).
#6 Keep greenhouse in a warm but partially shaded area (under a lath structure or a shade tree which transmits filtered light). Too hot or too bright sunlight will kill your cuttings. Don't fret if your leaves discolor or even fall off, your plant can still survive. If the cane turns black at the bottom, go ahead and fret because this is a sign of impending death (you may dispose of thes canes at this point). In 4-8 weeks you will see good sized leaves growing from the budeyes. This is the time to harden off your plants. Do not hesitate to cover the plant with the greenhouse on cool nights as it hardens. KEEP PLANTS IN THE GEENHOUSE WET AT ALL TIMES. THIS CAN BE JUDGED BY THE PRESENCE OR ABSENSE OF CONDENSATION ON THE INSIDE THE GREEHOUSE.
#7 Once fully hardened off, start to feed very dilute amounts (5-5-5 or 10-10-10) of CHEMICAL fertilizer for RAPID plant growth EACH TIME that you water. Add dilute humic acid as well (once or twice) to encourage nutrient uptake. When you get some sizeable (lush) growth, transfer to a 2 or 3 gallon black can filled with premiun potting soil and more mycorrhizae. Use chemicals for continued rapid growth or switch at this point to organic foods but expect slower growth. Your plants should reach nursery stock size within 12-18 months depending upon the food source and feeding frequency.
#8 Start multiple cuttings of any plant that you wish to multiply because some of these will fail. Some plants propagate in a snap and others just will not cooperate at all (this of course is why budding and grafting were invented). Friends and the CCRS Rare and Unusual Auction will be thrilled to receive the extras.
#9 It is illegal to asexually propagate patented roses. In practice, it is hard to imagine the need of or justification for propagating a patented rose. The patent is meant to prevent large scale suppliers from selling any significant number of "stolen" plants. Investigators are sent to insure patent compliance and suits may be brought for infringement. While It is highly unlikely that you would be discovered (much less prosecuted ) for duplicating only several copies of a patented plant for your own use, since it takes 1-2 years to obtain a reasonably sized plant from a cutting, it doesn't make much sense to try to grow your own when good specimens are commercially available.
#10 Got a better method or an improvement to suggest? Please let me know. Joel