One of the great joys of gardening is propagating new plants. There are many ways to do this, but one of the easiest is by snipping off a piece of stem, placing it in a potting medium, and nurturing the cutting until roots develop. At that point, you can transplant the rooted cutting into a pot or directly into the garden.
Learn How to Propagate Plants by Rooting Stem Cuttings
Propagating through stem cuttings is a form of cloning because the new plant will be an exact genetic match to the parent plant. That's not always the case with the other popular way to propagate plants—collecting seeds, germinating them, and planting. Many hybrid plants produce seeds that don't "grow true" to the parent plants, so rooting stem cuttings is the most reliable way to propagate hybrid plants.
Rooting stem cuttings is most often used to propagate houseplants, but there are many garden plants that you can propagate using this method. In cold climates, cuttings from tender garden plants, such as coleus or impatiens, can be taken in late fall, rooted indoors during the winter, and then planted outdoors in spring. And though it's a bit more difficult, many woody plants can also be propagated by snipping stem cuttings and rooting them.
There are two ways to root stem cuttings: placing them in water or embedding them in potting soil or another growing medium. Many plants, such as coleus, spider plant, and pothos, will readily root in water. But the water method can cause the roots to be quite fragile, and some plants resist rooting in water altogether. It's generally best to root your cuttings in some type of potting medium if possible.
When to Take Stem Cuttings
Stem cuttings can be taken and rooted at almost any time, but the technique is more successful when the plant is not in full bloom. When your goal is to propagate outdoor garden plants over winter, take your cuttings after the plant's bloom period is over in fall, or trim off any flowers or flower buds from the stem you are snipping off. A stem cutting that contains flowers or flower buds is putting too much energy into flower production to allow for good root development.
For shrubs and other woody plants, rooting via stem cuttings is most likely to succeed if you take cuttings from new growth that has not yet become woody. April through June is usually the best time to take cuttings from woody plants. Moreover, using a rooting hormone is essential when attempting to root cuttings from woody plants.
What Is Rooting Hormone?
Rooting hormones, whether in powder, liquid, or gel form, are chemicals that stimulate the growth of roots when applied to the severed end of the plant cutting before placing them in a growing medium.
Before Getting Started
Every plant species has an ideal type of potting mix that works best for rooting its cuttings. For many plants, an ordinary commercial potting mix based on peat moss works just fine. But other plant species root best in a more porous mix, such as vermiculite, sand, seed-starter mix, cactus/succulent mix, or some mixture of these ingredients. Never use ordinary garden soil to root your cuttings. It's always best to use a sterile "soil-less" growing medium because it will be free of soil pathogens that can ruin your attempts at propagation.
Do a little bit of research on any plant you want to propagate from stem cuttings. It's easy to learn what experts recommend as the best growing medium to use for propagation.
How to Make Your Own Plant Propagation Station
Equipment / Tools
- Sharp knife, scissors, or pruners
- Small trowel
- Pencil or sharp stick
- Soilless potting mix
- Planting tray or small pots
- Rooting hormone (optional)
Take Cuttings From a Healthy Plant
Cut a 3- to 6-inch-long piece from a healthy portion of the parent plant's stem, using a sharp knife or pruners to cut the stem at a 45-degree angle. This angled cut will maximize the area available for roots to develop. If possible, take cuttings from the newest growth on the plant
Each cutting should have at least two or three sets of leaves along its length. Make sure the cutting includes at least one growth node (a bump on the stem from which leaves or flowers sprout) that can be buried in the growing medium. Roots will sprout from this node, as well as from the cut end of the stem.
It's not uncommon for some attempts at propagation to fail, so it's best to take at least three cuttings to ensure success. Woody plants can be especially temperamental, so taking six or more cuttings is a good idea.
Trim the Leaves and Apply Rooting Hormone
Remove the leaves from the bottom node of the stem cutting. Usually, you can simply snap off the leaves. Make sure to retain at least three to four leaves on the stem cutting.
As an optional step, apply a powdered or gel rooting hormone to the trimmed end of the cutting and to the area where the leaves were removed. (Many plants will root successfully from cuttings without the use of rooting hormone, but using hormone can speed up the process, and it might be essential for some hard-to-propagate plants.) If you are using a powdered hormone, it helps to moisten the stem before rolling it in the powder. If you are using gel hormone, simply dip the end of the cutting into the hormone.
Plant the Cuttings
Prepare a planting tray or small pots with soilless potting medium, such as a seed-starter mix or vermiculite. Poke a hole in the medium with a pencil. Then, insert the end of each cutting into the growing medium and lightly tamp the mix around the stem of the cutting to hold it upright.
Tend the Cuttings
Most plants will not root well in full sun, so place the cuttings in a location where they will receive a 50/50 ratio of shade to dappled sunlight. For most plants, cuttings thrive on warmth and humidity, and the growing medium should be kept evenly moist but not drenched while roots develop.
Inspect the cuttings every two weeks, looking for new leaf growth and root development. If flower buds or blooms develop, pinch them off. New leaves will assist with root growth, but flowers divert energy away from root development.
Some plant species will require special treatment in order to root their cuttings. For example, the recommendation for some tropical plants might be to place the pot and cutting in a loosely tied plastic bag to increase the humidity level. Or, warmth-loving plants might require that you place the pot and cutting in a particularly warm place, or on a heating mat, during the rooting process. Always research the particular needs of the plant species you are trying to propagate.
Transfer the Cuttings
When you see that new leaf growth is developing along the stem of the cutting, it usually means that healthy new roots are established. Once you feel resistance when slightly tugging on the cutting, it means the roots are sufficiently developed. At this point, you can transfer the cutting to a new pot with fresh potting soil. A small trowel or large kitchen spoon is a good tool for scooping out the rooted cutting and transferring it to its new pot.
Remove leaves that turn brown or black as the stems are rooting. Discard any cuttings that turn soft or show other signs of rot or fungal disease, as these will soon succumb to their disease.
Moving New Plants Outdoors
When it's time to move the new plants you propagated from rooted cuttings to the outdoors, it is important to gradually acclimate them to outdoor conditions—a process known as hardening off. This process involves giving the new specimens increasingly longer exposure to the outdoors over a period of one to two weeks. Set the plants outside for only one to two hours the first few days and gradually increase the time exposure. Place plants outdoors during the warmer part of the day, but bring them back indoors during the cool nights. Gradually, the plant will become accustomed to the outdoor environment. Once nighttime temperatures are reliably at 50 degrees Fahrenheit or warmer all night, your new plants can be safely planted in the garden.