Propagating Roses by Air Layering- North Central ARS Convention



Hello everyone!  On Saturday, September 15th, I had the opportunity to make a presentation to the North Central Convention of the American Rose Society on rose propagation, specifically the process of air layering, which is a fascinating, 4,000 year old Chinese technique.  The slides that follow are self-explanatory, but I'll insert a few comments to give you the flavor of the presentation, as we go along.  The blog site doesn't lend itself well to importing PowerPoint presentations, so please excuse the slight blurriness of the slides, which I believe are pretty readable, though not perfect.

I will also append two articles at the end of the slides: one on air layering, from which I learned the technique, and the second on rooting stem cuttings by Mel Hulse, a legendary rosarian, who recently passed away.  Both of these articles originally appeared on the ARS website, but they are no longer available there.

Finally, please ask me questions, because I want to help you in any way I can.  My e-mail address is:

jack@falkerinvestments.com.  I hope you will have as much fun propagating roses as I have, over the years.  It's one of my favorite things to do in the garden.

These are pictures of my garden in Edina, Minnesota, an inner-ring suburb of Minneapolis.  Above, is my Buck "Earth Song" bed, composed entirely of roses that I have propagated.  Below is the same bed from a different perspective, with my pond and Morden Centennial bed in the background.

Above are Buck "Prairie Harvest", "Morden Blush" and "Winnipeg Parks", most of which I have propagated.  Below is my "Earth Song" bed again, on the morning of my presentation, which I couldn't resist including

This is my friend, Dick Lawson doing his first air layer this summer on a very sweaty, 95 degree day in Minnesota.  Thanks to Dick and Diane Lawson for these pictures of their beautiful garden.

In the picture above, Dick is scraping off the green phloem tissue to get down to white wood.  If you don't do this, roots will not form.  However, the biggest mistake you can make in removing the bark and scraping the green tissue off is cutting too deeply into the cane you are working on.  That will cause the cane to eventually break and ruin your work.  I have made this mistake several times and is really the only problem I've had in producing healthy, new plants by air layering.

Note that as long as the cane above your air layer is healthy and growing, your air layer is successful and should produce roots in a few weeks.

Above, you can see roots forming after about 3 or 4 weeks.  This is the point at which I do a little fertilizing by inserting a hypodermic needle with weak liquid fertilizeer to give the new plant a  boost.  Below, you see the results.  This is my favorite picture in the presentation.  Look at that root system!

Below is an air layer that Dick opened up prematurely to see what was going on.  This is very interesting because you can see the callous from which the new roots form.  Dick says he closed this one back up and the growth above continued to look good, so perhaps he will get a new plant after all.

Above and below are three new plants inside my cold-frame, where they will stay until the weather gets too cold for them to be outside, at which time they will come inside under the lights for the rest of the winter.

Above and below are two of the plants showing new growth, after being in their pots for about two weeks.  Note that they have been cut back to about six or eight inches, leaving several leaf nodes from which the new growth starts.  Also note that the plants have been stripped of all leaves to clear the way for new growth and reduce overhead for the new roots to support.  It's been a week since these pictures have been taken and both of these plants show significantly more growth today.

Below is the light stand in my basement, where the new plants live during the winter.  The stand uses ten 100-watt compact fluorescent bulbs, giving me 1,000 watts of light, while drawing only about 200 watts of power.  The bulbs are mounted in five dual sockets on an old shop light that I gutted and rewired.  I use a mix of high frequency (cool) and low frequency (warm) bulbs to give me a broad spectrum of light.  The plants are bottom-watered with a light fertilizer mixture and really grow well in this environment, such that they prolifically bloom and have to be cut back as the winter progresses.  My biggest problem is latent spider mites that are very hard to completely eliminate.  I wash the mites off every four days in the laundry room sink but they keep coming back if I let the washing go too long.  I don't spray any miticides or insecticides indoors.  The other problem I have, though not as pervasive as mites, is white flies.  They can be controlled by soaking some kitty litter (the paper variety) in Merit (imidacloprid) and putting it on the plants as mulch.

Here are the ARS propagation articles on Air Layering and Stem Cuttings.  Unfortunately, the pictures accompanying these articles did not copy to the blog site.  If you would like an e-mail copy of the articles, with the pictures, send me an e-mail: jack@falkerinvestments.com and I'll send them to you.

Propagating Roses by Air-Layering

by Leonora Tsukayama
East Hawaii Rose Society

ROSE PLANTS WITH ROOTS IN 21 DAYS! It's possible if done correctly and conditions (plant health, growth pattern and weather) are right. It happens in my own back yard and within months I am admiring blooms from my new plant. The method is called air-layering. About 4000 years ago the Chinese people used it to duplicate plants that were difficult to root by cuttings. It is similar to the old layering method of bending a lower flexible branch to the ground, then placing a heavy rock on the branch and waiting for a long time to see the roots grow. There is no trauma to the mother plant; in fact, it will promote growth as if you pruned that branch. Healthy new shoots will sprout below the air-layer.

My mom taught me this technique many years ago when there were no garden centers to buy plants and supplies. She would drive up to the forest and pick her own sphagnum moss and would then air-layer the plants of her friends. Some of these plants were the lychee, lemon, pikaki, evergreens, roses and a lot more. After a couple months she would come home with a gleam in her eyes and a new plant in her hands.

HOW DOES IT WORK?
The leaves make nutrients from the sun and send it down the phloem tissue (a greenish substance located just under the bark) to the roots. When this "pipeline" is cut and kept moist the nutrients will collect at that point and in ten days form a callus from which the roots will develop. The air-layered part will still receive its water and nutrients from the roots through the xylem tissue located inside the woody part of the stem.

Some advantages of air-layering are higher percentage of success, a jump-start in plant growth by at least two years, stronger root system, very low cost, no "baby sitting" cuttings, and you get personal satisfaction when you see the fast results.

SUPPLIES:

- Sphagnum moss or Jiffy Peat Pellet (soaked in water)
- Sharp knife
- Rootone (liquid or powder)
- A small brush
- Clear plastic sheet (6" x 10") or sandwich bag (cut open)
- Twist-ties
- Plant labels

PROCEDURE: Choose a green, pencil-size stem and make a safe area to work in by removing thorns, leaves, and branches.
About 1/4" below a leaf node, make a cut around the stem and 1" below that make another cut. Then remove the bark between the two cuts.
With the knife blade, scrape the wood, making sure the bark and the green tissue is completely removed or it may not develop roots.
Brush on Rootone
Wrap with the clear plastic sheet making small pleats as you go around the stem, forming a sack. Then 5/8" below the cut area, snugly twist-tie it. (Not too tight in order to allow the plant to expand). Pull the plastic sheet down to expose the site. This makes it easier to place the moss around the cut. Squeeze out water from a handful of moss or a Jiffy Peat Pellet pot until just moist. Form a wad about the size of your palm or make a vertical tear down the Jiffy Pot.
Wrap moss or Jiffy Pot 3/4" above and below the bare stem. Pull up the plastic and straighten, making sure it is air and water-tight. Secure top with the twist-tie (Not too tight in order to allow the plant to expand). Label your plant as desired (plant name, color, type, date, etc.)
Periodically examine the layer. Most rose plants show their white roots beneath the plastic sheet after 21 days, some may take longer.

PLANTING: The roots will show through the plastic sheet. When they are about an inch long (about 21 to 28 days), clip the stem off below the layer. Soak in water if you are not ready to plant, but no longer than three days. Gently remove ties and plastic. Carefully loosen moss or tear some of the netting from the Jiffy Pot. Trim off all the leaves and young shoots, then cut off side branches till the plant is about 10" tall. Plant your new air-layered rose. OBSERVATIONS AND TIPS: Healthy mothers make healthy babies. Pamper the mother plant with extra liquid fertilizer and water two weeks before this procedure to insure vigorous growth. It is harder to peel the bark off during the dry season. It's a good idea to make sure that the mother plant is well hydrated. We must respect our hard working hybridizers who spend many years developing new rose plants. Patented roses should not be cloned. Stems that are green but not tender develop roots faster than brown older ones. Add a couple drops of household bleach and 1/4 teaspoon of liquid fertilizer to the water before soaking the moss. Bleach kills bacteria and fertilizer promotes growth for the new plant. Potting soil can be used as a growing medium, but I find it hard to fill the plastic sack. Disinfecting your knife with alcohol or hydrogen peroxide is good, but be sure to rinse with clean water before using it on your next plant. Using a foil or a dark cloth as a cover will promote root growth and prevent the tender young roots from burning in the hot sun. However, I don't like it because it makes a great hiding place for lizards. If you notice the layered part starting to wilt, remove by cutting it off below the clear plastic sack and check to see if there's a callus. If so, soak in water until it hydrates, then plant it. Sometimes it may grow. HAPPY PROPAGATING!

Rooting Roses - A Rose Rustler's Toolkit Rosarian Contact: Mel Hulse - Volunteer Maintenance Director of the San Jose Heritage Rose Garden, San Jose, CA (This article has been widely circulated on the Internet; the most recent version has been improved with the inclusion of Paul Barden's photos.) Here is that article, complete with the pictures: http://www.paulbardenroses.com/hulse.html Rose rustling is great fun! Whether admired in a bouquet, a friend's garden, or found on a Sunday drive, knowing that you can clone the rose that takes your fancy expands your love of your rose growing hobby. Hardwood rooting is a classic amateur method of propagation, but is available only in the winter when you can't see most roses bloom. Bud grafting requires ready root stock and is mostly suited to professionals and experienced amateurs. Softwood rooting is available when you see the rose blooming. I have had the good fortune in turning softwood cuttings into growing bushes planted the San Jose Heritage Rose Garden and others. I've started 1,000s of cuttings with near 100% success when cuttings meet the specs I'm giving you and good success with less select cuttings. Remember that all roses started out as seedlings on their own roots so grafting is not essential to their growth. Old Garden Roses, English Roses, Shrubs, and Miniatures are generally good candidates for rooting cuttings because most grow vigorously on their own roots. Most modern roses such as Hybrid Teas and Floribundas are sold budded onto rootstock. Most newer ones grow well on their own roots; a few do not. A small number of old varieties, such as Spinosissimas and some other roses with dense prickles as well as a few modern roses, are difficult to propagate and may take many tries to gain success. Please remember that asexual reproduction of roses still under patent protection (now 20 years) is illegal, especially if for sale. This technique stresses three goals - simplicity, successful rooting of your softwood cuttings, and ease of transfer of the rooted cutting to your garden. EQUIPMENT AND SUPPLIES: * A very bright interior window ledge or table in front of the window with no direct sun. I am having success outside under a covered, shaded deck in our warmer climate (overnight temperature above 45 degrees). * One gallon ZipLock type storage bag(s). * Bypass shears. * A very sharp pocket, paring, or budding knife, preferably carbon steel. * 1 gallon or more container of water. * Potting soil. For bags, you want a mixture that holds together well when damp. Ingredients should be of fairly fine texture. In the West, Supersoil works well. Shultz Potting Soil with Fertilizer from Walmart And Whitney Farms Seed Starting Mix work also. * Spray bottle of about 16 oz. capacity. Put in 1/8 teaspoon Miracle Gro for Roses, K-Mart's cheaper clone or Peter's 20-20-20, 1/8 teaspoon baking soda to prevent fungus, and a few drops of dishwashing liquid to make it cling. Fill with water. The mix should suds a little when shaken. If not, add more dishwashing liquid. If you make a gallon, use a teaspoon each of fertilizer and baking soda. * Rooting powder or liquid. Useful, but not essential. I prefer liquid Dip 'n' Grow because I can vary the strength. * A garden marking pen and labels. Home Depot sells a small kit of 40 labels and the right kind of marking pen. * Notebook and pen with waterproof ink. * 10" wooden skewers of the type used for shish ke-bab. * 1-gallon plastic planting pots. You know; those black things! * 14" saucers. Cheap, plastic terracotta color ones from Home Depot work fine. * Patience! SELECTING THE CUTTING: The ideal in order of priority: 1. A stem with a spent flower is desirable. A stem with a flower bud with no color showing is too young. 2. Include four - 5 leaflet leaves on the stem. 5 leaves are acceptable. Fit in the baggie governs the length. Note. For this and the remainder of this article, "5 leaflet leaves" includes varieties that have 7 or more leaflet leaves. 3. A heel at the bottom. This is the place where a branching cane grows out of a main cane. Cut right up against the main cane. Faulting this, cut immediately below the bottom bud. 4. Soft, flexible wood, 1/4" in diameter or less. 5. Disease/virus free. At left: An ideal cutting. For climbers that are sports of a bush form of the same rose, use the end of a climbing cane rather than a lateral even though it has no bloom on the end. Use of a lateral may cause the climber to revert to the bush form. Nature doesn't always give you the ideal and all of the above guidelines can be broken if necessary, but try for the ideal. Keep the cutting damp until ready to use. Wrap loosely with a wet paper towel and put in a plastic bag. Keep cool. Refrigerate, if possible. Use within a week.   PREPARING THE BAG: * Write the rose name or found location and date on a new baggie with the gardening pen. Note all known information about the rose with date in your notebook. If you are more diligent than I, you can keep notes on your cuttings' progress as a reference for future propagation efforts. * Fold the zipper part down a couple of inches to keep the zip groves clean. Put 3 cups of potting mix into the bag. No more. * Pour a scant cup of water into the bag. Grab the bag above the potting soil and knead the water into the soil. While doing this, tuck the bottom corners of the bag under the soil. The mass should look like a ball. When thoroughly mixed, test for enough water. - If water leaks out when the bag is inverted, and squeezed it is too wet. Squeeze out the excess water. - Put the bag top upon a flat surface. Press the top of the soil down to form a 1+" deep, round pancake. Stick a finger into the soil in the middle. If the soil breaks apart, you need to add water and recheck. * Set aside on a flat surface.   PREPARE AND INSERT THE CUTTING: Snip off the stem 1/2" above the top-most 5-leaflet leaf. Strip off the bottom leaves leaving 1 large or 2 regular 5-leaflet leaves. These are required to produce a hormone during rooting and to start growth. If the cutting does not terminate in a heel, locate the lowest bud eye on the cutting--make a cut straight across directly below the lowest bud eye (the "bud eye" is the swelling right above the junction of the leaf with the cane.) Here are several guidelines for unusual cases: * Lateral stems with mature leaves off the main cutting cane. Cut (don't try to break) these off very close to the cane. The bud eye they came from can still produce more breaks. * 'Broken' (opening) lateral buds with immature leaves on the upper part of the cutting. Leave the highest one alone. It will grow. Carefully cut off any others with your shears. * Very small or broken leaves at the top. Leave 3 leaves. Break off the thorns on the bottom inch of the cane being careful not to disturb any minute buds. Note that there are many tiny buds above a heel. Carve a shallow cut through the bark from 1/2 - 3/4" above the bottom of the cutting to the end of the cutting on the opposite side from a bud. Avoid cutting any bud eyes. At right: A typical cutting, about 6 inches long with bottom leaves trimmed off. The cutting will form a whitish callus along this score and along the cut end of the cane. This is where roots emerge. Dip the bottom inch of the cutting in liquid rooting compound or for powdered rooting compound, water and then the compound and knock off any excess. Place the cutting in the hole you made with your finger with the leaves running the same way as the zip grooves at the top of the bag. Press the potting soil around the cutting. It is best if the cane is slanted from one end of the bag toward the other. Be careful in this process to avoid letting thorns puncture a hole in the bag. If this happens, use another bag. Unfold the top of the bag to be ready to close it. Spray the inside generously with the spray bottle you prepared. If any foreign material got on the zip groves, wash it off with the sprayer. Close the bag from both ends toward the middle leaving an inch unclosed. Be sure you do not catch leaflets in the zip grooves. Blow into the bag to expand it like a balloon and zip it up completely. Put the baggie in bright, indirect light preferably inside. Direct sun will scorch and kill the cuttings. At left: Inserting the cutting. From now on, handle the bag only from the top. Set it down only on a hard, flat surface (not your knee.) The idea is minimum displacement of the cane and new roots. Note: While not recommended, it is possible to root 2 or 3 cuttings in a single bag if you are pressed for space. Sorting out roots during potting or later planting will be a potential source for loss. I have found that with 4 or more cuttings some usually die. WATCH IT GROW: Now comes the fun! Roses are very individual and perform differently. New growth may appear in 8 days ('The Fairy') or may take over 3 months ('Belinda' with a hard cane.) Some will form a lot of roots without breaking a bud; some will become tiny bushes in the bag with no visible roots for some time. The presence of leaves does not mean that your cutting has 'struck' (taken). Stored energy in the cutting can support a lot of top growth, but if the cutting doesn't callous and roots don't appear, the cutting will eventually die. Most of the care needed is an occasional bag reinflation. The bag provides the complete humid environment the cuttings need - a mini greenhouse. Don't worry if some of the original leaves turn yellow and drop so long as the cane is green. Remove the dead leaflets (use tweezers) and any mushrooms or fungus. If the soil cracks at the cane, gently move soil into the crack and firm it in place. The skewers are great tools for this. Give the inside of the bag several shots out of your spray bottle before reinflating the bag. Some of these dummies think they should bloom in the bag!!!! Watch carefully for buds and nip them immediately. If you don't, you may lose the rose or set it back months. As long as the cutting cane is green, any of the original leaflets or new growth are still alive, or roots are apparent and vital, your rose is alive. Don't despair! Above: The bags with their cuttings placed under lights. A bright place with indirect light is also a good choice. HARDENING: When to open the bag? This is the tough one. Here are some conditions that should work: * Roots show on the bottom of the bag and you have 2 or 3 five leaflet leaves of new growth. * You can't see roots, but new top growth has approached the top of the bag and is not spindly or growth lower on the cutting looks mature. * There are strong roots on the bottom of the bag for several weeks and a bud eye has swollen but not broken. Opening the bag to harden the plant is the most critical time in the process. If you lose the rose, it will probably be at this point. Be sure that you have time to care for the rose on the day you open the bag and the day after. It doesn't hurt to put off the "coming out" until you have time. Patience!!! Open the bag for about one inch for about 3 hours the first day. Use a skewer stuck through the opening and into the soil to hold the bag vertical. Check the rose every hour. If the new growth droops or the leaflet edges brown, close and blow up the bag, wait a few days and try again. If the rose is unaffected by the opening, close the bag after the 3 hours. The next day, double the opening period and the size of the opening. Keep watching carefully. Keep up these increases each day until the bag is completely open. Backup a step if the rose can't take it. After the bag has been completely open a day, fold down the zip part. Keep in place another 4 days. Give it a spray once or twice every day.   POTTING AND PLANTING YOUR TREASURE: Now you will see the reason why I told you to tuck in the bag corners. If possible, do this next step on a plastic/newspaper covered table outside. Fill a clean pot one-half full with potting mix. The potting mix need not be the type you used in the bags. Place the pot in a saucer and wet the soil until it runs into the saucer. Indent the soil in the middle. Here's the hard part. Holding the bag over the pot, slip your hand into the bag under the potting soil centered under the plant. Slide the bag from under the soil mass and your hand while keeping the potting soil root ball as intact as possible. Slowly work the root ball and the plant into the pot with the stem centered and at the same angle it was in the bag. At right: Once the root system is sufficiently developed, as it is here, carefully remove the plant with soil intact. Be sure to cradle the root mass carefully to avoid too much trauma. The roots are delicate at this stage! Some potting soil will break off, but don't worry. Once the mass is into the pot, add the soil that broke off and gently firm it into place maximizing the plant position without significant root displacement. Make a tag with the info from the bag. Stick the skewer in the side of the pot and hang the tag on it. Later, when you have a solid cane, you may place the tag there, but don't block buds. Return the potted rose in its saucer to the same location you had it while in the bag. Keep water in the saucer to a level where some air can enter the top of the pot drain holes. This keeps the potting soil "sweet." Leave it there about 4 days. Your eyes will tell you when it is happy enough to move. If your weather permits, 50-degree nights or above, move it outside. Start in a bright or dappled, shaded location with a little morning sun and slowly move it during a week or two into full sun. Depending on your climate (I'm in USDA zone 9b, Sunset 17), you may need to move it inside at night for a while (I don't). Your eyes should be the judge of how strong the rose is and how fast it can progress. It ain't rocket science, just judgment and ... Hey! patience. If you have a lot of gallon pots with cuttings, an old plastic garbage can lid can be a saucer to seven. After a week or so of success in full sun, continued growth, and given warm weather, plant it in the ground or a larger container, just as you would any other potted rose giving regard to the variety, vigor, and its requirements for space and sunlight. Always plant it or place it in a larger container if roots show at the drain holes. Through all this and for the first month in the garden, make sure it gets water every morning. All of this timing depends on watching the rose. Proceed if the rose is growing and gaining strength, back off if it droops or the leaves brown. And, just like teenagers, some try to flower too soon! Pinch off buds until you have a good strong plant, at least 3 months. (You may cheat and leave one bud to see the first bloom. But then, pinch it off!) Fertilize with liquid fertilizer or fish emulsion at least every other week. I've also found that misting each morning with the fertilizer/baking soda mix definately promotes healthy growth. Stop fertilizing at the beginning of September in cold country; later in warmer climes. Provide extra protection the first winter.Repeat-blooming roses will usually put forth a first bloom in about 8 weeks. Once blooming roses won't bloom until the next year because they bloom on old wood. Growing roses from cuttings is not hard. Both the process and the results are fascinating and the roses you grow are somehow more yours to enjoy. This paper expands on instructions in the Rose FAQ (Frequently Asked Questions) available on the World Wide Web at: http://www.ars.org. I acknowledge my debt to rosarian Cheryl Netter who first described the baggy method, nurseryman friend Tom Liggett and others who provided added details and insight, and Paul Barden who helped illustrate this article with his great digital photos. These instructions are tailored to my area (USDA zone 9).