The secret of rooting cuttings can be summed up in two words. “Timing and technique”.
When you do your cuttings is every bit as important as how you do them. So if you do the right thing, at the right time of the year, your efforts are sure to bring success. Through this article you will learn both.
“Rooting Hardwood Cuttings of Deciduous Plants”
Hardwood cuttings are much more durable than softwood cuttings which is why hardwoods are the best technique for the home gardener. A deciduous plant is a plant that loses its leaves during the winter. All plants go dormant during the winter, but evergreens keep their foliage. Many people don’t consider Rhododendrons, Azaleas, and Mountain Laurel evergreens, but they are. They are known as broad leaf evergreens. Any plant that completely loses its leaves is a deciduous plant.
There are three different techniques for rooting cuttings of deciduous plants. Two methods for hardwood cuttings, and one for softwood cuttings. In this article we are only going to discuss rooting cuttings using the hardwood methods. If you are interested in softwood cuttings, you’ll find a very informative article at http://www.freeplants.com
Of the two hardwood techniques is one better than the other? 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 doing hardwood cuttings of deciduous plants, you should wait until the parent plants are completely dormant. This does not happen until you’ve experienced 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.
Unlike softwood cuttings of deciduous plants, where you only take tip cuttings from the ends of the branches, 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.
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 year’s 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.
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.
When rooting cuttings this way 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 reduce the chance of disease. Once you have all of your cuttings made, dip the bottom of the cutting in a rooting compound. Make sure you have the right strength rooting compound (available at most garden stores) for hardwood cuttings. 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 12” 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 6” 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.
I know this sounds crazy, but rooting cuttings this way does work. To increase your chances of success you can cover the butt ends of the cuttings with moist peat moss before filling in the hole. Make sure you wet the peat moss thoroughly, then just pack it on the butt ends of the cuttings.
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, then water thoroughly to eliminate any air pockets.
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 really is no exact science when it comes to rooting cuttings, so now I am going to present you with a variation of the above method. This method still applies to hardwood cuttings of deciduous plants. With this variation you do everything exactly the same as you do with the method you just learned, 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, or anytime during the winter when the ground is not frozen. 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.
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 like Weeping Cherries or other ornamental trees. Rooting cuttings of ornamental trees is possible, but only using softwood cutting techniques.
Now let’s discuss rooting cuttings of evergreens, using hardwood techniques.
Hardwood cuttings of evergreens are usually done after you have experienced two heavy frosts in the late fall, around mid November or so. However, I have obtained good results with some plants doing them as early as mid September, taking advantage of the warmth of the fall sun. When doing them this early, they need to be watered every day.
Try some cuttings early and if they do poorly, just do some more in November. Hardwood cuttings of many evergreens can be done at home in a simple frame filled with coarse sand.
To make such a frame, just make a square or rectangular frame using 2” by 6” boards. Nail the four corners together as if to make a large picture frame. This frame should sit on top of the ground in an area that is well drained. An area of partial shade is preferred.
Once you have the frame constructed remove any weeds or grass inside the frame so this vegetation does not grow up through your propagation bed. Fill this frame with a very coarse grade of sand. The sand used in swimming pool filters usually works. Mason’s sand is a little too fine. If you have a sand and gravel yard in your area visit the site and inspect the sand piles. Find a grade that is a little more coarse than masons sand. But keep in mind that most any sand will work, so just pick one that you think is coarse enough. If water runs through it easily, it’s coarse enough.
Make sure you place your frame in an area where the water can drain through the sand, and out of the frame. In other words, don’t select a soggy area for your cutting bed. Standing water is sure to seriously hamper your results.
Making the evergreen cuttings is easy. Just clip a cutting 4-5 inches in length from the parent plant. Make tip cuttings only. (Only one cutting from each branch.) Strip the needles or leaves from the bottom one half to two thirds of the cutting. Wounding evergreen cuttings isn’t usually necessary because removing the leaves or needles causes enough injury for callous build up and root development.
Dip the butt ends of the cuttings in a powder or liquid rooting compound and stick them in the sand about 3/4” to 1” apart. Keep them watered throughout the fall until cool temperatures set in. If you have some warm dry days over the winter, make sure you water your cuttings. Keep in mind that sand in a raised bed will dry out very quickly. Don’t worry about snow. Snow covering your cuttings is just fine, it will actually keep them moist, and protect them from harsh winter winds. Start watering again in the spring and throughout the summer. They don’t need a lot of water, but be careful not to let them dry out, and at the same time making sure they are not soaking wet.
This method of rooting cuttings of evergreens actually works very well, but it does take some time. You should leave them in the frame for a period of twelve months. You can leave them longer if you like. Leaving them until the following spring would be just fine. They should develop more roots over the winter.
Rooting cuttings of the following plants is very easy using this method. Variegated Euonymus varieties, Taxus, Juniper, Arborvitae, Japanese Holly, Boxwood, and English Holly. Rhododendrons and Azaleas prefer to have their bottoms warmed before they root.