If you like a good bargain, propagating trees and shrubs can be an enjoyable part of gardening. It does require a bit of time, energy and equipment, along with a spirit of experimentation and curiosity. I’ll cover the two basic kinds of proagation techniques, layering and cuttings.
Layering is a form of reproduction requiring minimum equipment and few other resources. Your success rate should be high because the new plant isn’t separated from the mother plant until after it has rooted. Best of all, you can propagate as many or as few plants as you want, for little, or no cost. Here’s how to layer:
- Choose a one-year old stem you can bend without breaking and prune the foliage and side stems along the section you want to layer.
- Push the stem to the ground and pin it with a U-shaped piece of wire (tip: an old wire hanger cut to size will work). Bend the section with leaves and stem, up sharply.
- You can boost the rooting by cutting an inch long slit on the bottomside of the stem and keeping the cut open with a toothpick.
- Mound 3 to 6 inches of soil over your pinned area and either use a flat rock or mulch on top to preserve moisture.
- Once the layer has a good root system, it can be cut away from the parent. Transplant immediately or leave it in place until you are ready to move it.
- If you select a longer stem, you can stake multiple layers using the same method as above.
Layering works well for a lot of common shrubs, including azaleas, rhododenrons, barberries, magnolias; brambles such as raspberries and blackberries, viburnums and lilacs.
Multiplying your plants by cuttings takes more time and resources than layering, but you gain the advantages of being able to reproduce more plants in less time.
Although the general information I am going to provide will work with many species, many woody plants have exact needs. So you will need specific information on rooting the plant you want to propagate. Available sources include your local library, the agriculture extension service, or a local botanical garden.
You will need some basic equipment to do woody cuttings:
- A sharp knife or pruners
- A seed flat or 6-inch plastic pot
- Twist ties and plastic bags (or, you can use a greenhouse mist bench)
- Rooting medium – a good general purpose mixture is sterile coarse sand and peat
- Rooting hormone
- A bright location with indirect light in a cool area. Bottom heat if possible
- A cold frame and nursery bed.
There are three types of cuttings; softwood, semi-hardwood and, hardwood. They are named for the developmental stage of their tissue and for the way that they are cut.
Softwood cuttings are taken from actively growing stems in the spring or summer. Cut at a 45 degree angle across the stem just below a node, using a 2 to 4 inch piece of stem.
Semi-hardwood cutting are taken from new growth which has slowed but hasn’t completely hardened off, in the spring or summer. You will begin by pruning off an entire shoot. Depending upon how long the shoot is, you may be able to get several 4 to 6-inch long cuttings. Trim each cutting just below a node at a 45 degree angle. Then pinch or cut the top just above a node.
Hardwood cuttings are generally taken after the leaves have dropped (for deciduous plants) and the current season’s growth has hardened off in the fall. The cuttings are 6 inches or longer and about 1/4 inch in diameter. You will cut straight across the stem below a bud. The top piece of the cutting is cut at a 45-degree angle above a bud. For evergreens, mallet and/or heel the cutting that includes a small part of the older wood.
Tomorrow I will give you some tips you can use for better success with cuttings.