Growing plants from cuttings is far from a new technique. Ever since plants have existed, they’ve been sprouting from cuttings all on their own. A branch falls to the ground and, if the conditions are ideal, produces roots and becomes a new plant. Taking cuttings at home is just as simple, in fact even easier, as you get to control the conditions whereas Mother Nature often makes things difficult.
First a definition: taking a cutting involves removing part of a plant and stimulating it to produce roots and new stems and leaves. In other words, the severed part, the cutting, becomes a new plant in its own right.
You can take cuttings from many plant parts. Some plants, especially weeds like quackgrass and Japanese knotweed, are well known for their ability to regenerate from a small section of root or rhizome section left in the soil. When you do this on purpose, you call it a root cutting. When it happens in your garden, you call it a $&*%#@!
Also you can take leaf cuttings or even leaf section cuttings from such certain plants, such as African violets, crassulas and snake plants (Sansevieria). In fact, in under laboratory conditions, you can grow many plants from just about any green part of their anatomy.
On the other hand, the “plant part” the mostly likely to provide a viable plant from the widest range of plants under home conditions is the stem. You can take stem cuttings from just about any plant that has a stem: houseplants, shrubs, trees, herbs, perennials and many, many more.
Using Houseplants as an Example
Let’s concentrate here on taking stem cuttings of houseplants, as not only do most root easily from stem sections, but they’re readily available at any season. The technique described below, however, can be applied to outdoor plants as well. Yes, you can follow exactly the same steps with exactly the same products under exactly the same conditions to root cuttings of a rosebush, a forsythia or an echinacea.
When to Take Cuttings?
Cuttings succeed more easily when the plant is actively growing. Spring (March, April and May), when houseplants begin to emerge from their winter lethargy thanks to the influence of increasingly long days, is a particularly favorable time for taking cuttings, but you can continue right through the summer into early autumn. In fact, September is a very popular month for taking cuttings of many plants usually treated as annuals (pelargoniums, fuchsias, petunias, begonias, etc.) that you can then grow indoors over the winter to replant in the garden the following summer.
Step by Step
1. Begin by selecting a container. A traditional plastic pot is fine, but you can also recycle any small container, such as a yoghurt cup, as long as you punch a hole in its bottom for drainage. Avoid large pots: plants root better in small pots about 2 to 3 inches (5 to 7.5 cm) in diameter or in plug trays. If you want to, though, you can start several cuttings in a larger pot or in a tray.
2. Fill the pot with potting mix or seed-starting mix or use perlite or vermiculite. Avoid garden soil and even compost: you’ll want the growing mix to be fairly sterile at first.
3. Moisten the mix thoroughly and allow any excess water to drain out.
4. Using a pencil, punch a hole into the potting soil in the center of the pot. This is the hole into which you’ll be inserting your cutting.
5. Now, with a sharp knife or pruning shears, cut a healthy stem with at least three nodes and preferably four or five nodes (a node is the spot on the stem where leaves are attached or used to be attached).
6. Remove the flowers and flower buds (they would just sap the new plant’s energy). Also remove the lower leaves: you’ll want to insert the stem into the mix to a depth of at least 2 nodes and any leaves that end up covered in potting soil could rot… and you don’t want rotting material near your young plant!
7. For plants you want to see branch abundantly, such as coleus and hibiscus, pinch the tip (that is, remove the bud at the end of the stem). This will stimulate the production of several new stems rather than just one. For stem cuttings of plants where a single stem is the norm (African violets, dieffenbachias, dracaenas, philodendrons, etc.), don’t pinch.
8. Among easy-to-root plants – and that includes philodendrons, coleus, pileas, begonias and just about any plant with a soft stem and no bark – no rooting hormone is necessary. Woody plants, such as hibiscus, dracaena and croton, are more difficult to root and, for these plants, buy a rooting hormone and apply a bit to the lower extremity of the cutting. This hormone will encourage recalcitrant stems to produce roots.
9. Slip the cutting, bottom end down of course, into the hole you previously prepared, up to the second or third node. Gently press the soil down and around the cutting so it’s held upright. (You may need to stake very large cuttings.)
10. The vast majority of cuttings root better under high humidity, so cover the pot with a dome or transparent plastic bag, creating a mini-greenhouse where the relative humidity will be almost 100%.
11. Place the pot in a well-lit spot, but away from direct sunlight, and at fairly warm temperatures: 70 to 75°F (21-24°C).
12. Now, wait! Some cuttings are quite quick to root (a coleus may be well-rooted in only 4 to 7 days!), but most will take two or three weeks, even more than a month for woody plant cuttings.
13. You’ll know the cuttings have rooted when you see new leaves start to appear, a sign that roots are beginning to do their job. At this point, remove the mini-greenhouse and place the plant (no longer a cutting) in a place suited to its needs.
Cacti and Succulent Cuttings
Cacti and succulents don’t need high moisture in order to root and in fact, tend to rot when exposed to high humidity.
For these plants, cut off a stem, but don’t plant it right away. Let it dry for a while, until the wound callouses over, before potting it up. You can simply lay the cuttings on their side while you’re waiting. It takes 2 to 3 days for most succulents to form a callus, but a month or more for those with a very thick stem (large cactus and euphorbias, especially).
Stick the cutting upright in a pot of dry soil (not moist as you would for other plants) and don’t water right away. Wait until you see signs of growth, which can take a month or more. Yes, as odd as it may seem, these plants will more easily produce roots in dry soil! And of course, don’t cover them with a mini greenhouse!
Once new growth appears, start a normal watering program and your “succulent cutting” will soon be a thriving plant!
Taking Cuttings in Water: a Horticultural Faux Pas
The following will surprise many gardeners because there is a long tradition of rooting cuttings in a glass of water, but that’s really not a good technique. It sometimes works fine, but in general it ends badly.
The problem is that the roots produced on a cutting started in water acclimate to an aquatic environment. When you later transplant the cutting to a pot (and very few plants will be spending all their life in a glass of water), the aquatic roots die and rot, forcing the young plant to start from scratch and produce a new set of roots. Often, it no longer has enough energy for that and dies.
So to ensure good rooting success, I suggest you always start your cuttings directly in some sort of substrate such as potting soil.
As Your Plant Grows…
Depending on the size of your cutting, the small pot in which it rooted will likely become too small quite rapidly. Don’t hesitate to repot your cuttings into a pot of a size more appropriate to its dimensions. Since it’s never wise to put a small plant in a big pot, you may need to repot your young plant into a larger pot 2 or even 3 times in the first year of its life. It will slow down after that.
Now that you know how to do it, try taking cuttings yourself: your thumb is greener than you think!