The Secret of Growing Landscape Plants from Cuttings
The secret of growing landscape plants from 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.
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 it’s leaves during the winter. All plants go dormant during the winter, but evergreens keep their foliage. Many people don’t consider Rhododendrons, Azaleas, and and Mountain Laurel evergreens, but they are. They are known as broad leaf evergreens. Any plant that completely loses it’s leaves is a deciduous plant.
There are two different ways to do hardwood cuttings of deciduous plants. 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.
Method Number One
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. 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 reduce the chance of disease.
Once you have all of your cuttings made, dip them 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. It is beneficial to cover the butt ends with moist peat moss before filling in the hole.
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.
Method Number Two
When using the second method for rooting 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, 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.
Hardwood Cuttings of Evergreens
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 is early, they need to be watered everyday. 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 course 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. This frame must be well drained, and coarse sand drains very well. Fine sands do not drain well at all. 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. 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.
Hardwood cuttings of many evergreens will root this way, 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.
This method of rooting hardwood cuttings can and will work well for variegated Euonymus varieties, Taxus, Juniper, Arborvitae, Japanese Holly, Boxwood, and English Holly. Rhododendrons and Azaleas prefer to have their bottoms warmed before they root.
If you have questions for Mike McGroarty visit his website, http://www.freeplants.com and post them on the message board where you can learn lots of gardening tips and communicate with other gardeners. While at his website you can learn how to start your own profitable backyard nursery. If you would like a copy of Mike’s booklet, “The Secret of Growing Landscape Plants from Scratch”, send $4.00 to: Garden Secrets, P.O. Box 338, Perry, Ohio 44081