As a home gardener, fall should be a very special time for you. Fall is the best season of the year for plant propagation, especially for home gardeners who do not have the luxury of intermittent mist. The technique that I am going to describe here can be equally effective for evergreens as well as many deciduous plants.
The old rule of thumb was to start doing hardwood cuttings of evergreens after you have experienced at least two hard freezes. After two hard freezes the plants are completely dormant. However, based on my experience it is beneficial to start doing your evergreen cuttings earlier than that. So instead of doing “by the book” hardwood cuttings you’re actually working with semi-hardwood cuttings. The down side to starting your cuttings early is that they will have to be watered daily unless you experience rain showers. The up side is that they will start rooting sooner, and therefore are better rooted when you pull them out to transplant them.
To prepare an area in which to root cuttings you must first select a site. An area that is about 50 percent shaded will work great. Full sun will work, it just requires that you tend to the cuttings more often. Clear all grass or other vegetation from the area that you have selected. The size of the area is up to you. Realistically, you can fit about one cutting per square inch of bed area. You might need a little more area per cutting, it depends on how close you stick the cuttings in the sand.
Once you have an area cleared, all you have to do is build a wooden frame and lay it on the ground in that space. Your frame can be as simple as four two-by-fours or two-by-sixes nailed together at each corner. It will be open on the top and open on the bottom. Just lay it on the ground in the cleared area, and fill it with a coarse grade of sand.
This sand should be clean (no mud or weed seed), and much coarser than the sand used in play box. Visit your local building supply center and view its available sand piles. It should have different grades varying from very fine to very coarse. You don’t want either. You want something a little more coarse than their medium grade. But then again it’s not rocket science, so don’t get all worked up trying to find just the right grade. Actually, bagged swimming pool filter sand also works and should be available at discount home centers.
Once your wooden frame is on the ground and filled with sand, you’re ready to start sticking cuttings. Wet the sand the day before you start, that will make it possible for you to make a slit in the sand that won’t fill right in. In this propagation box you can do all kinds of cuttings, but I would start with the evergreens first: Taxus, Junipers and Arborvitae.
Make the cuttings about 4-inch long and remove the needles from the bottom two-thirds of the cuttings. Dip them in a rooting compound and plant them in the sand about an inch deep. Most garden centers sell rooting compounds. Just tell them that you are rooting hardwood cuttings of evergreens.
When you make the Arborvitae cuttings you can actually remove large branches from an Arborvitae and just tear them apart and get hundreds of cuttings from one branch. When you tear them apart that leaves a small heel on the bottom of the cutting. Leave this heel on. It represents a wounded area, and the cutting will produce more roots because of this wound.
Once the weather gets colder and you have experienced at least one good hard freeze, the deciduous plants should be dormant and will have dropped their leaves, and you can now propagate them. Just make cuttings about 4-inch long, dip them in a rooting compound and stick them in the bed of sand. Not everything will root this way, but a lot of things will, and it takes little effort to find out what will or won’t work.
This is a short list of just some of the things that root fine this way: Taxus, Juniper, Arborvitae, Japanese Holly, Blue Boy/Girl Holly, Boxwood, Cypress, Forsythia, Rose of Sharon, Sandcherry, Weigela, Red Twig Dogwood, Variegated Euonymus, Cotoneaster, Privet and Viburnum.
Immediately after sticking the cuttings, thoroughly soak the sand to make sure there are no air pockets around the cuttings. Keep the cuttings watered once or twice daily as long as the weather is warm. Once winter sets in you can stop watering, but if you get a warm dry spell, water during that time.
Start watering again in the spring and throughout out the summer. The cuttings should be rooted by late spring and you can cut back on the water, but don’t let them dry out to the point that they burn up.
By fall you can transplant them to a bed and grow them on for a year or two, or you can plant them in their permanent location. This technique takes 12 months, but it is simple and easy.
Mike McGroarty is the author of The Gardener’s Secret Handbook and you can read his gardening blog at mikesbackyardnursery.com