Using Cuttings to Start New Plants
by Don Janssen, Extension Educator
The flowering annuals you planted in late May haven't hit their peak yet, but it's not too early to think about taking cuttings for indoor flowers this winter. Taking cuttings of popular flowering annuals such as coleus, fibrous-rooted begonias and impatiens now, rather than waiting until frost is threatening, is a kind of insurance. If something happens to the first cuttings, you'll still have time to try again. If you wait too long, one chance may be all you get.
It's still a good idea to take more cuttings than you think you'll need. All cuttings won't necessarily root and grow into new plants.
Select healthy, vigorous plants as your source of cuttings. Begonias, impatiens and coleus are propagated from stem tip cuttings. These are the growing ends of shoots. For propagation, select shoots with no flowers or flower buds. Use a sharp knife to remove the cuttings just below a leaf. Cuttings can be as long as 4 inches or as short as 1 inch.
Remove the leaves from the lower ends of the stems, leaving at least two at the tip. Dip the cut end of each stem in rooting hormone. With a pencil make a hole in the moist sand, vermiculite, perlite or some other sterile rooting medium and insert the stem. Water the medium to firm the cuttings in the container.
To retain moisture in the medium, cover the containers with clear plastic, then place them in a warm spot where they will not be subject to direct sunlight. In direct sun, heat will build up under the plastic and cook the young plants. Roots should form in two to three weeks. When the plants start to put out new leaves, it's time to transplant them carefully into new containers of potting soil.
Though you can raise plants from cuttings on a sunny windowsill, coleus, especially, will tend to produce long, straggly stems with widely spaced leaves under low light conditions. For best results, grow these plants directly under fluorescent lights. Sixteen hours a day under a combination of cool white and warm white or daylight bulbs plus occasional pinching of stem tips will encourage plants to branch rather than straggle and promote continuous flowering in begonias and impatiens.
Outdoor plants brought indoors may bring outdoor problems with them. Insects may come inside with them. They may go unnoticed for a while, until a population explosion occurs in the absence of the natural controls that keep their numbers in check outdoors. Check cuttings and transplants closely for insects and other problems and treat the pests or discard the plants as needed to prevent a major infestation.
Next spring, these plants can be the source of cuttings for new plants for your garden. Follow the same procedure used to start them. Or simply prune them back and set them outside on warm days to adjust gradually to outdoor conditions. Then, when the danger of frost is past, plant them back in the garden for another summer.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office