Propagating Hardwood Cuttings of Deciduous Plants
by Mike McGroarty
There are two different ways to do hardwood cuttings of deciduous plants. Is one better than the other? I really don't know. It depends on exactly what you are rooting, what the soil conditions are at your house, and what Mother Nature has up her sleeve for the coming winter. I have experienced both success and failure using each method. Only experimentation will determine what works best for you. Try some cuttings using each method.
When propagating hardwood cuttings of deciduous plants, you should wait until the parent plants are completely dormant. This does not happen until you have had a good hard freeze where the temperature dips down below 32 degrees F. for a period of several hours. Here in northeastern Ohio this usually occurs around mid November.
Propagation Method Number One
When taking softwood cuttings of deciduous plants you take tip cuttings from the ends of the branches only. That rule does not apply to hardwood cuttings of deciduous plants.
For instance, a plant such as Forsythia can grow as much as four feet in one season. In that case, you can use all of the current years growth to make hardwood cuttings. You might be able to get six or eight cuttings from one branch.
Grapes are extremely vigorous. A grape vine can grow up to ten feet or more in one season. That entire vine can be used for hardwood cuttings. Of course with grape vines, there is considerable space between the buds, so the cuttings have to be much longer than most other deciduous plants. The average length of a hardwood grape vine cutting is about 12" and still only has 3 or 4 buds.
The bud spacing on most other deciduous plants is much closer, so the cuttings only need to be about 6-8" in length.
Since hardwood cuttings must be done during the winter months, you probably will want to work in your garage or basement where it is not quite so cold. Of course there are still some nice days after the first freeze when working outside is possible.
Making a deciduous hardwood cutting is quite easy. Just collect some branches (known as canes) from the parent plants. Clip these canes into cuttings about 6" long. Of course these canes will not have any leaves on them because the plant is dormant, but if you examine the canes closely you will see little bumps along the cane. These bumps are bud unions. They are next years leaf buds or nodes, as they are often called. When making a hardwood cutting of a deciduous plant, it is best to make the cut at the bottom, or the butt end of the cutting just below a node, and make the cut at the top of the cutting about 3/4" above a node.
This technique serves two purposes. One, it makes it easier for you to distinguish the top of the cutting from the bottom of the cutting as you handle them. It also aids the cutting in two different ways. Any time you cut a plant above a node, the section of stem left above that node will die back to the top node. So if you were to leave 1/2" of stem below the bottom node, it would just die back anyway. Having that section of dead wood underground is not a good idea. It is only a place for insects and disease to hide.
The above photo is a collection of hardwood cuttings ready to be buried or planted out, depending on the technique you are using. The bottom of the cuttings are to the right. Notice how I made my cuts just below the nodes, but not into them. In this photo you are looking at Burning Bush, Red Twig Dogwood, Rose of Sharon, and Purple Sandcherry.
It is also helpful to actually injure a plant slightly when trying to force it to develop roots. When a plant is injured, it develops a callous over the wound as protection. This callous build up is necessary before roots will develop. Cutting just below a node on the bottom of a cutting causes the plant to develop callous and eventually, roots.
Making the cut on the top of the cutting 3/4" above the node is done so that the 3/4" section of stem above the node will provide protection for the top node. This keeps the buds from being damaged or knocked off during handling and planting. You can press down on the cutting without harming the buds. Although not necessary, it helps to make the cut at the top of the cutting at an angle. This sheds water away from the cut end of the cutting and helps to keep disease and insects away from the cuttings.
Once you have all of your cuttings made, dip them in a rooting compound. Make sure you have the right strength rooting compound for hardwood cuttings. You can buy rooting compounds on line at various garden centers and grow shops.
Line them up so the butt ends are even and tie them into bundles. Select a spot in your garden that is in full sun. Dig a hole about 10" deep and large enough to hold all of the bundles of cuttings. Place the bundles of cuttings in the hole upside down. The butt ends of the cuttings should be up. The butt ends of the cuttings should be about 3" below the surface. Cover the cuttings completely with soil and mark the location with a stake, so you can find them again in the spring.
Over the winter the cuttings will develop callous and possibly some roots. Placing them in the hole upside down puts the butt ends closest to the surface, so they can be warmed by the sun, creating favorable conditions for root development. Being upside down also discourages top growth.
Leave them alone until about mid spring after the danger of frost has passed. Over the winter the buds will begin to develop and will be quite tender when you dig them up. Frost could do considerable damage if you dig them and plant them out too early. That's why it is best to leave them buried until the danger of frost has passed.
Dig them up very carefully, so as not to damage them. Cut open the bundles and examine the butt ends. Hopefully, you will see some callous build up. Even if there is no callous, plant them out anyway.
You don't need a bed of sand or anything special when you plant the cuttings out. Just put them in a sunny location in your garden. Of course the area you chose should be well drained, with good rich topsoil.
To plant the cuttings, just dig a very narrow trench, or using a spade, make a slice by prying open the ground. Place the cuttings in the trench with the butt ends down. Bury about one half of the cutting leaving a few buds above ground. Back fill around the cuttings with loose soil making sure there are no air pockets. Tamp them in lightly. Water them on a regular basis, but don't make the soil so wet that they rot.
Within a few weeks the cuttings will start to leaf out. Some will more than likely collapse because there are not enough roots to support the plant. The others will develop roots as they leaf out. By fall, the cuttings that survived should be pretty well rooted. You can transplant them once they are dormant, or you can wait until spring. If you wait until spring, make sure you transplant them before they break dormancy.
There are many wholesale nurseries where the employees spend a great deal of their time during the winter months making hardwood cuttings using this method. Years ago I worked for a nursery that produced hundreds of thousands of grape plants each year. The owner of the nursery expected us to produce 5,000 cuttings each day. Of course he would give us about two weeks to work our way up to that figure. Once we were able to make 5,000 a day, he would then put us on piece work. We earned eight hours wages for 5,000 cuttings. Eventually I was able to make 5,000 cuttings in six hours.
Propagation Method Number Two
When using the second method for propagating hardwood cuttings of deciduous plants you do everything exactly the same as you do with method number one, up to the point where you bury them for the winter.
With method number two you don't bury them at all. Instead, you plant the cuttings out as soon as you make them in the late fall. In other words, you just completely skip the step where you bury the cuttings underground for the winter.
Plant them exactly the same way as described for method number one. As with all cuttings, treating them with a rooting compound prior to planting will help induce root growth.
You can propagate hardwood cuttings of deciduous plants throughout most of the winter, as long as the ground is not frozen.
Hardwood cuttings work fairly well for most of the deciduous shrubs. However, they are not likely to work for some of the more refined varieties of deciduous ornamentals. If your curious about how to propagate a particular plant, just click on "How to Find the Propagation Technique that is Right for Your Plant".
Copyright © 1998 by Michael J. McGroarty
Michael McGroarty is a hands-on plant propagation expert, proprietor of the plant propagation site, FreePlants.com and is the author of several books, publications and videos about plant propagation techniques.