A rose cutting, a stick if you will, can regenerate roots, stems, leaves, other stems, buds, blooms and finally, more "sticks." That uncanny cycle propels intrepid rose gardeners to seek, propagate, preserve and occasionally identify enigmatic roses.
Heritage Rose Society's members in Texas stage "rose rustling" trips and haunt abandoned gardens to propagate unknown and relic varieties. In my own garden, I simply prefer to grow a rose that once belonged to a friend.
Under optimum conditions and depending on the variety, each of the hardwood cuttings from this winter's pruning of dormant rose bushes has the capacity to be a young bush in bloom by summer. Those cuttings are also grist for the mill of pruning parties. At this year's ninth annual gathering, 300 cuttings from Clyde Henley's 136 rose bushes in Glendora found perpetuity among 60 friends.
One efficient, easy and incredibly economical method of rose propagation, adapted here for home gardener, is a technique selected by Claire Martin III, head rose gardener at the Huntington Botanical Gardens in San Marino.
Materials needed are: a sharp pruning shear or knife, Harmondin 1 (a rooting hormone sold in packets at nurseries), a half-gallon milk carton (I find this superior because the paper easily peels away from the root mass and seems to eliminate transplanting shock), sterilized potting soil, a plastic dry-cleaner bag, two 24-inch wooden dowels, plant labels and a pencil to use as a probe.
Take 8-inch cuttings from dormant rose bushes, placing the bottom section immediately into water. If propagating has to be postponed, cover them with wet paper towels, slip the bundle into a plastic bag and store them in the refrigerator. Some rosarians believe this additional enforced cold dormancy enhances rooting. The procedure is also a convenience for collectors who travel to find their rare roses.
With propagating materials assembled, slit drainage cuts at the base edge of each side of the milk carton and fill the container with potting soil to 1 inch below the top. Remove any remaining leaves from the rose cutting and make a fresh cut just under the last node. Then, in a procedure used by the Bermuda Rose Society, scar the outer stem tissue or cambium layer in order to produce more callusing that precedes rooting. With the sharpened edge of the pruning shear, or a flat razor, lightly peel a 1/2-inch thin sliver from two sides of the stem's end.
Tap a small portion of the rooting compound onto a piece of paper. This prevents contamination of the remaining hormondin and contact with the fingers easing handling and disposal. Because the powder contains hormondin and a fungicide, it is capable of causing fungus skin infections.
Dip the scored end of the rose cutting into the rooting compound and tap off the excess powder. Use the pencil to make a hole to a depth that supports an inserted cutting then press the soil around the cutting.
Place the two dowels opposite each other inside the container to elevate the plastic cover above the cutting to a height that allows new growth. Water thoroughly to settle and saturate the soil, making sure that the drainage holes are functioning. Cover the entire unit with a clear, plastic bag. To retain the moisture, tuck the ends of the bag underneath.
For ideal light, position the impromptu "greenhouse" in an unobstructed location that looks straight up to a clear sky but receives no direct sun. The north side of a wall is perfect.
Check Moisture Level
Examine periodically and maintain consistent moisture; beads of water inside the cover tell you everything is going well.
Rooting times differ for species and varieties. Winter hardwood cuttings are easier to keep alive but take a long time to root. For that reason Martin advises home gardeners to use soil as the rooting medium so that nutrients will be immediately available to the young roots. However, for the quicker rooting semi-hardwood cuttings taken from ripened portions of the current year's growth during the growing season, he advises using a rooting media mix of half perlite and half builders sand horticulturally referred to as "mister mix."
For optimum rooting of semi-hardwood cuttings, Martin instructs rose-gardeners to take cuts about 8 inches long with a minimum of four sets of leaves from a mature rose that is just beginning to drop its petals. At that time, the sugars are still concentrated in the stem.
To preserve the vitality and prevent wilting of the semi-hardwood cuttings, rose propagators carry a container of water into which they place the freshly cut stem, or--if several different varieties are to be collected--labeled plastic bags, each containing a wet paper towel. At the first opportunity, buds and flower heads are removed because they withdraw nutrients from the stem.