How to Cut and Layer Plants


While the subject of cloning can be touchy in some circles, it's a common occurrence in the plant world. Instead of starting out as a seed, certain plants need to be cloned, or vegetatively propagated, from stem cuttings or root cuttings of a mother plant. Other plants require layering, which involves growing a new branch or stem out of an existing one.

How to go about propagating depends on the type of plant you're working with. For example, you're best bet with a lilac bush is to take a stem cutting. On the other hand, horseradish plants are propagated using their root cuttings. Azaleas and shrubs with creeping branches require the layering process to establish new growth.

Learn more about what types of plants require the technique you want to use in this article. We'll give you helpful step-by-step instructions along with color photos and illustrations to help you in your propagating efforts of cutting and layering plants. To make things easier, the article is broken down into the following sections:

  • Cutting Stems and Roots

    Learn how to grow new plants from stem cuttings for such species as geraniums, asters, chrysanthemums, and bellflowers. Cutting stems involves trimming a growth tip from a mature plant and then placing the cutting in a container filled with a rooting medium. By following the care tips you'll find here, that stem cutting will soon turn into a new plant ready to transplant and thrive on its own.

    This section also addresses why other plants, such as Oriental poppies, are best cloned by using cuttings from their roots. Cutting roots will involve digging out the root before the shoots begin to show. We'll teach you about the best time of year for taking root cuttings, and we'll also show you how to properly care for the cutting, as well as the parent plant.

  • Layering and Transplanting

    Understand the technique of layering to propagate shrubs that are difficult to root, such as creeping rosemary and other shrubs with low-growing branches. Layering involves nicking the bark of an existing plant and dusting the exposed area with a rooting hormone. If all goes according to the plan, soon a new branch tip will grow from the nick in the bark, and voila -- you'll have a new plant to bring life to your garden.

    This section will also give you tips on how -- and when -- to transplant that new plant you've grown. Since transplanting new growth can be quite a delicate process, you'll want to gather as much information as you can to ensure that your new seedling or cutting will continue to grow, even in the hardest of conditions.

It would almost be a shame not to propagate the healthy, hardy plants in your garden, especially once you understand the ease of cutting and layering. Whether you want to duplicate your favorite Oriental poppy, or simply multiply your azaleas so they fill out your garden, cutting and layering are the techniques for healthy plant propagation. So, get "growing" with the helpful tips and techniques outlined in this article.

Cutting Stems and Roots

Certain plants don't grow from seeds. Named cultivars like "David" phlox must be cloned (vegetatively propagated) to get a plant with all the exact qualities of its parent. This is done by rooting sections of stems or sprouting chunks of roots. Clump-forming plants can be divided into several pieces, and some stems can be rooted while still attached to the mother plant.

Cuttings from Stems

Most annuals are grown from seeds. However, impatiens, fibrous begonias, coleus, and geraniums can be grown from stem cuttings.

To propagate stem cuttings, select a mature plant that is in a stage of active midsummer growth. Prepare a container filled with rooting medium. It should be at least 3 to 4 inches deep, filled with 2-1/2 inches or more of rooting medium. Clean, coarse builder's sand, a mixture of half perlite and half peat moss, or half perlite and half vermiculite are good choices. Fill the container with the moistened medium, then let it settle and drain for a half hour.

Take stem cuttings in the morning. Using a sharp knife, cut off growth tips just above the node, or the point where a leaf or side shoot attaches to the main stem. Each of the cuttings should be between 3 and 6 inches in length and have 4 to 6 nodes. The stem tissue should be easy to cut through.

Cut growth tips from the parent plant with a small, sharp paring knife.

Layering and Transplanting

The process of layering is typically used to propagate hard-to-root shrubs like azaleas. Layering also works well with shrubs that have low-growing or creeping branches, like creeping rosemary. Layered stems develop roots while still connected to the mother plant, which helps encourage the rooting process. Follow these steps for layering:
  • In the spring, select a low, flexible branch that will bend down to the ground easily.

  • Prepare well-drained but moisture-retentive soil where the stem will touch the ground.

  • Nick the bark off the side of the stem that will touch the ground and remove the leaves near the nick. Dust the cut with rooting hormone.

  • Cover the barren and nicked stem with soil. Top it with a rock, or pin it in place with a stake or metal pin.

  • The branch tip will become the new plant. If it is an upright grower, stake the tip upright to give it a good shape.

  • Keep the rooting area moist for several months, until roots develop and become large enough to support the new plant.

  • Cut the new plant free from the parent branch and transplant it to a pot or new site in the garden.

Transplanting

Whether your new plant is coming from your own seedlings, stem cuttings, or the garden center, care is needed when it's time to plant it in the garden. Ideally, transplant in the evening or on a cloudy day to keep the sun from causing too much water loss in the plants and burning tender roots or leaves. Use the following tips to help you successfully transplant your new plant.

  • Don't transplant seedlings into a larger pot until they have one or two sets of true leaves. This allows seedlings to develop enough roots to be self-supporting even if a few roots are lost in the process. It's also a time when seedling roots are fairly straight and compact, making them easy to separate from nearby plants.

    How can you tell when the time is right? It's not as simple as counting the number of leaves on the stem, because the seedling usually has an extra set of leaves called cotyledons, or seed leaves. They emerge first and provide food that nourishes the sprouting seedlings. When you look closely, you can see that cotyledons are shaped differently from true leaves. Squash seedlings, for instance, have oval squash-seed-shaped cotyledons that are easy to spot. But the true leaves are broad and lobed.

    Transplant a new seedling when it grows its first set of true leaves.
    ©2006 Publications International, Ltd.
    Transplant a new seedling when it grows its first set of true leaves.


  • "Harden off" seedlings and cuttings before they go out into the garden. When growing in the protection of a windowsill, light garden, or greenhouse, young plants are tender and can be easily damaged by strong winds or sun. Toughen them up (a process called hardening off) to make the transition from indoors to outdoors successful.

    Days 1 and 2: Put well-watered young plants outdoors in a shady location for several hours. Bring them back indoors when the time is up.

    Days 3 and 4: Increase the length of time seedlings stay outdoors in the shade.

    Days 5 to 7: When well adjusted to shade, gradually move sun-loving plants into brighter light, starting with an hour of sun the first day.

    Day 8 and beyond: When seedlings can stay out all day without burning or wilting, they are ready for transplanting.

"Growing" a new plant from an old one, whether through seedlings, cuttings, or layering, can be quite rewarding. By following the suggestions in this article, you'll have more new plants than you know what to do with.

©Publications International, Ltd.