Spring and summer is when most people think about propagating garden plants, but caring for tender cuttings through the heat of summer can be challenging. Fortunately, a number of popular trees and shrubs can be rooted easily in the dormant season via hardwood cuttings [see table] and require much less attention.
Hardwood cuttings are made from mature, dormant stems that do not bend easily. Crape myrtles, grapes, and pomegranates all root well with this technique. The process to take hardwood cuttings begins in the fall right after the leaves drop. At that time, use sharp, clean pruners to take six-inch-long, pencil-diameter cuttings from vigorous shoots on the plants you want to propagate. If it is a tree or shrub that produces suckers from the stems or roots, use the suckers for your cuttings. Their increased vigor means that they will usually root and grow easier than cuttings taken from other areas of the plant. Also make note of which end is up; upside-down cuttings won’t root! It can sometimes be difficult to tell on a leafless cutting, but the leaf buds on the stem usually point upward. Keep cuttings moist and out of direct sunlight. If they dry out before being stuck they are much less likely to survive.
Hardwood cuttings of hardy plants like crape myrtle and forsythia may be stuck right away. But for plants prone to cold damage, like pomegranate and fig, take the cuttings right after the leaves drop and store them in the crisper drawer of your refrigerator through the winter and stick them in the early spring. These stored cuttings will generally root with greater vigor than fresh ones taken in the spring. If you do store cuttings, wrap them in a damp (not wet) paper towel inside of a plastic bag so that they don’t dry out and make sure they don’t freeze.
You may stick hardwood cuttings into beds of sand or even directly into garden soil, but I prefer to stick them in containers with a 50/50 mix of pine bark and horticultural perlite. However, any well-draining potting soil will work. Fill a clean 3-gallon nursery pot, or similar container with drain holes, two-thirds full with the soil mix and water to settle and remove large voids. Then stick the cuttings upright until only the upper two inches of the six-inch cutting are exposed.
Space cuttings about 2 inches apart. Ten to twelve cuttings should easily fit in the container. The cuttings need to stay cool so that they don’t sprout leaves too early, but don’t let them freeze either. Keeping them in an unheated garage or shed through the winter is ideal. Check on them periodically to ensure that the soil doesn’t dry out. Soggy soil, however, is equally problematic so make sure the container drains well. Once the danger of a hard freeze has passed, move the containers outside into a dappled sun area, such as, under a deciduous tree.
Rooting hormones, typically sold as powders, may improve rooting, particularly on harder to root plants. If using a rooting powder, dip the bottom 1-2 inches in the powder and tap the cutting to knock off any excess.
Pre-dibble a hole in the potting media with a pencil or stick that is only slightly larger in diameter than the cutting. Carefully insert the cutting to avoid rubbing the powder off and firm the soil around the cutting. Also, don’t water the cuttings right away as this will wash the hormone from the cutting and reduce its effectiveness.
Cuttings that survive and root should produce new leaves in the spring. Resist the urge to tug on them, as the new roots will be tender and easily damaged. Wait until you see healthy roots emerging from the container’s drain holes, then carefully remove the rooted cuttings from the container, separate, and repot into their own containers. Then share your new plants with friends and neighbors!
Common Plants that Root from Hardwood Cuttings
|Boxwood||Rose of Sharon|
|Grape (Bunch and Muscadine)||Willow|
Originally published 10/16