Fall and winter is the best time to do some vegetative propagation, especially of woody plants. We’ve all seen some plants “sucker,” producing other plants from their roots. Suckers of grafted roses should be immediately removed, since they’re pulling strength from the roots instead of letting the grafted portion use that growth. Shrubs such as lilacs and some viburnums sucker freely, and so do apple trees. Apples belong to the same family as roses, and those suckers, too, are detracting strength from the tree.
If you have a lilac that has developed suckers apart from the main shrub, sever the roots between it and the main shrub now. In spring you can dig the sucker out and plant it where you prefer. Simple layering is another fairly easy way to get a “free” duplicate shrub. Several months prior to your planned layering encourage vigorous new growth low on the shrub in any way possible.
Then, once the shrub has entered dormancy (usually that means winter), trim off side shoots from about four inches from tip back to its connection with the shrub. Dig a shallow trench for the shoot, and back toward the main shrub make an angled cut into the shoot (not through it, though), and peg the shoot down into the trench, then cover with soil. Gently angle the tip up out of the soil.
Next autumn, sever the new plant from the parent, and a few months later, replant it where you want it.
Sign Up and Save
Get six months of free digital access to The Idaho Statesman
Do you have a hardy perennial herb you treasure, and want more of it? One way to do that is to pile soil around or onto the top of the plant, leaving leafy branches at least an inch above the soil. Those branches should root, allowing you to divide plants from the mother-rooted plant in late spring.
Hardwood cuttings are most prone to develop roots when cuttings are made at leaf fall and just before bud break. That time is when the abscission layer is intact and ready to let go of leaves. To determine this, run your fingers over the branch, and if leaves fall off easily, it’s that time. Cuttings taken just before bud break must be closely monitored, however, for leaves will draw moisture from the cutting. Cuttings taken at leaf fall and immediately put into the soil for rooting are far less labor intensive.
Take cuttings of dogwood, black currant, cotoneaster, viburnum, poplar, rose, willow, currant or spirea that are at least pencil-thick and have at least three buds on each cutting. Make a sloping cut at the top of the cutting, and a 90-degree cut across the bottom. This difference will help you orient the cutting to grow and leaf out normally. If you plan to root them immediately, dip the base end into rooting powder such as Rootone, flick off the excess, then lower the cutting into a hole in potting soil, leaving two buds above the soil level and a third slightly below the surface. Many propagators use cuttings that are 10 to 14 inches long, but shorter is more successful in developing roots. One of the dangers in the life of cuttings is the dessication or drying out of the cutting.
Instead of immediately rooting your cuttings, you can bundle them and put them vertically in damp sand or soil. It’s a good idea to label them and the location of your stash. When you prune your grapes in February, you can take cuttings, using the slanted cut to indicate “up” and the cross cut as “down.” Take cuttings of pencil-thick parts of the vine that have nodes at least four inches apart. Some of use install grape vine cuttings upside down in a hole, fill it in and mark location in a way that pets or squirrels can’t dislodge. This upside down storage forces growth hormones to the tops of the cuttings that will be the bottoms when you separate the bundle into individual cuttings and put into soil to root. Those growth hormones will force rooting a little quicker than if they’d been stored right side up to begin with.
A bit of Idaho in Ireland
A friend in Ireland tells me one of the most popular tomatoes that gardeners grow there is the Latah, named by professor Art Boe of the University of Idaho, he began working on varieties in the 1970s. It’s a small tomato, usually known as “salad sized,” that is tolerant of cool growing weather. Summers are not hot in Ireland, as they are here. I’ve grown this variety, but found more flavorful varieties suited me better.
I will not again grow a “green” tomato, though. I don’t separate fruits at harvest, and the green tomato just rots as I’m waiting for it to turn color. My tomato beds need revitalized this winter.
Send garden questions to firstname.lastname@example.org or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.