propagation

There are two primary ways to propagate roses. Asexual reproduction is usually used to produce a duplicate of the parent plant. Sexual reproduction, i.e. growing roses from seed, is primarily used to create new varieties of roses.

Common methods of asexual propagation of roses are softwood rooting, hardwood rooting, and bud grafting. Limited space permits only a brief description of softwood rooting.

Old Roses, English Roses and Miniatures are generally good candidates for rooting cuttings because they usually grow vigorously on their own roots. Modern Roses such as Hybrid Teas and Floribundas are usually sold budded onto different rootstock. Some Modern Roses do grow vigorously on their own roots, while others do not. Below is a description of softwood rooting from Karen Baldwin with some changes.

Rose Propagation à la Zip Loc Baggies

Making the Cutting:

• Preferably take a cutting on which the bloom is barely spent, so that all the petals have just recently dropped off. It is okay to take a cutting earlier, but at least make sure color is showing in the bud. These are indications of the maturity of the wood in the stem – you want something in between the extremes of greenwood and hardwood.
• Try to have at least four separate leafsets under the bloom, and a five‑leaflet set at the bottom of the cutting. (Each spot where the leafsets meet the stem forms a “node,” where the bud eyes are, and from which roots can form. Hybrid teas tend to have fewer “nodes” spaced farther apart than Old World roses, and thus require a longer cutting, generally speaking.) Make a clean bottom cut with a sharp, clean pruning tool 1″ below the last node. Try to leave about 1/2″ of cane above the top leafset.
• Keep your cuttings fresh in water while you gather more, until you’re ready to plant them.

Planting the Cutting:

• Fill a 1‑gallon Zip Loc baggie 1/4 to 1/3 full (about 3″) with STERILE loose potting mix. (e.g., 1/2 peter’s potting soil and 1/2 vermiculite).
  A 2‑gallon Zip Loc baggie may be better since it will give the leaves more room, but use the same depth of soil you’d use in a 1‑gallon baggie, since you’ll be watching for roots growing through it, later.
• Moisten the mix but do not make it extremely wet. Use 1 tsp. Miracle Gro per 1 quart of water, to provide some initial nutrients (which may help avoid yellowing and leaf‑drop). With your hands, firm the soil down well, within the baggie. The soil should be very damp, but there should be no standing water in the bottom.
• Snip off the stem a little above the top‑most leaf set (i.e., remove the flowering part). Try to leave about 1/2″ of cane above the top leafset.
• Strip off the bottom two sets of leaves (where the stem will be pushed into the soil).
• Score the bottom part of the stem along its length (vertically) for an inch or so. (An Exacto‑knife works nicely for this purpose, but fingernails will do fine.) Roots will form along this score.
• Dip scored end of cutting into rooting compound, a couple inches deep. Knock off the excess (you can get too thick a layer). Stick the cutting a couple of inches into the soil.
• If insects have eaten the leaves during previous rooting attempts, you may wish sprinkle a very small amount of diazinon or other insecticide on the soil surface. Be especially careful if you are using chemicals indoors.
• Mist the cutting and the interior surfaces of the baggie with a spray bottle filled with the following mix (to avoid fungus and mildew growth in the closed “terrarium” environment). Do not use spray can fungicides or insecticides; in the closed environment, the chemicals can overwhelm then kill a new young plant.
  1 quart water 1 tsp. miracle gro 1 tsp. baking soda (no more!) 2‑3 drops dishwashing liquid (to make it cling)
• Zip baggie almost shut. Breathe into it until it expands kind of like a balloon, and zip the rest of the way closed. (Keep it closed unless it deflates enough to warrant breathing into it again.)
• Put in bright, INDIRECT light – (e.g., behind sheers in a southeast‑facing window) WARNING!!! if it gets direct sun or too much heat it will scorch (eventually turning black) and likely die! You may have to experiment a bit to find the best exposure; you might hedge your bets by placing some in different locations until you find the best spot for your house.
• Clear away any leaves that might drop from the stem, reinflating the baggie after removing them.

Potting the Cutting:

• Look for roots along the bottom of the baggie in two or three weeks. A few stubborn ones may take six weeks, and there is a report of one incredibly obstinate plant that took over 10 weeks!
• Acclimation to air outside the bag is tricky. To be careful,
  (1) when you see some top growth, unzip the baggie just a little for a few hours the first day, then seal it up again.
  (2) For the next few days, unzip the baggie the same amount, but leave it open for a few more hours each day.
  (3) Next, leave it open all the time, but increase the amount the bag is unzipped each day for about a week, until it’s fully open. Don’t rush it.
• Put good soil into a 1‑gallon pot, leaving room for the addition of the new plant and its soil. Place the baggie atop the soil, and cut the plastic away (this can be slightly tricky). Firm the soil around the plant only very lightly.
• Keep the same lighting in the same location (protected from too much direct sun) for a week, leaving the cutting unmolested to give its disturbed roots a chance to heal.

Planting Outdoors:

• After they have spent a week in their pots, you can either move them into more light inside for the first winter, or (preferably) move them outside.
• When moved outside, set them in indirect sun at first, bright but shaded, and leave them there for a week. (If your area gets cold at night, you may need to move them inside at night for a while.) The next week, move the plant bit by bit toward and then into full sun. (Note: Gro‑lights don’t normally put out nearly enough light for roses, though it can probably be done.)
• When kept inside for their first winter, especially in zones 5 and below, place them in a spot where they’ll get more light. (When planted outside in the same summer they were rooted, even with a heavy mulch, many more will be lost to winter kill since the new little roses won’t always have enough roots to carry them through. Also, chinooks (intense, warm winds) do their damage too. By keeping them inside for their first winter, and planting them in the spring, they will be better‑established by the next fall.)
• Plant late enough to avoid those nasty springs that get warm, causing the roses to break dormancy, only to follow up with a hard freeze!
• Remember that your rose will grow in size; prepare a good‑sized area of soil with added organic material as appropriate to your locale. on establishing a strong root system.