Fall Propagation: Semi-Hardwood Cuttings

As leaves continue to fall, most gardeners are putting their gardens and landscapes to bed. Plants are being cleaned up, leaves and debris raked up, and late season flowers such as mums and pansies are finding a home in the garden.

Some gardeners take time in the fall to prune plants such as roses, but I advocate against fall pruning (though our own West Virginia University garden calendar suggests pruning roses this week — a point with which I disagree). Aside from pruning out anything damaged or diseased, most sources I find suggest pruning in the winter (things that bloom mid-summer and later) or after blooming ends (things that bloom early spring). There are a few things that break this rule, such as fruit trees and shrubs (prune them in winter), but all-in-all it is a good rule to follow.

There are several reasons why I suggest against pruning in the fall. First, pruning stimulates new growth. If temperatures are mild for a while after you prune, you could get new growth on the plants that then succumbs to freezing damage. Secondly, many things that bloom early in the season (before mid-June) form their flower buds in the fall. If you prune them all away, you’ll be sorely disappointed by the lack of flowers next year. With our recent severe winters, I think leaving pruning until after the deep freeze may be beneficial to overwintering. Leaving more material on the plant over winter means there will be more plant left if there’s any freeze damage that needs to be pruned out in the spring.

That being said, there are some trees and shrubs that you may want to snip a few branches from this time of year. Not for pruning, but for propagating new plants by cuttings.

Most gardeners these days have forgotten the practice of starting new plants by cutting. It has become all too easy to buy new plants at garden centers, catalogs or online. Meanwhile, for a minimal investment (most people will have the pruners, pots and potting mix necessary), you could be producing nearly free plants to use or to share.

Propagation through cuttings is simple for some plants and nearly impossible for others. Starting with the cutting at the correct level of maturity is the first step of improving the chances of successful propagation. Cuttings can be either made of softwood (or new growth), semi-hardwood, or hardwood growth. Each of these are collected during different times of the year.

Softwood cuttings are generally taken in the summer (June-August), and consist of the new, fleshy growth from the current year. Semi-hardwood cuttings are the ones taken during the fall, and are this year’s new growth that has partially matured. Hardwood cuttings are taken late in the fall or early winter when the plants are completely dormant.

This time of year is when you want to be taking semi-hardwood cuttings of plants that do best with that type of cutting. A short list of those plants include Abelia, arborvitae, Azalea, boxwood, Euonymus, holly, Pyracantha, Rhododendron, and roses.

Begin by using a sharp, clean set of pruners or a knife to take the cutting from the plant. You’ll want a section 3 to 5 inches long that includes at least two nodes (places where leaves or twigs attach). Remove any leaves or twigs from the bottom node, leaving the node intact.

To increase your chance of rooting success, using a rooting hormone (easily purchased at most local garden centers) will help get roots growing on the cutting faster. You typically dip the cut end of the cutting into the powdered hormone right before planting.

Place the cut end of the cutting into the soil, being sure to put the bottom node (with leaves removed) below the soil. Nodes are an area of new growth, and once under the soil they will begin to produce roots instead of leaves.

If you have an indoor space to propagate plants, you can use it to get the quickest growth. However, you will have to keep the plant healthy and happy all through the winter until you can plant it next spring.

While warmth will result in the speediest propagation, it is also possible to root many of these plants outdoors in a protected area through the winter. The most important thing to remember is that these plants do not have roots to take up water, so you will need to keep them humid throughout the winter.

To protect them from the dry winter air, use a plastic row cover or low tunnel, a cold frame, cloches, or wrap the pots with plastic. You’ll have to realize that these methods do create heat in the sunshine, so you may need to vent them on warm, sunny winter days to keep them from cooking your plants. If you only have a few cuttings, you can use the trick that my grandmother (and many other grandmothers) used to propagate her roses — use a canning jar as a makeshift cloche to protect the plant over winter.

– See more at: http://www.wvgazettemail.com/article/20151018/GZ05/151019518/1158#sthash.AIJDmmil.dpuf

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