Following from my initial tutorial on plant propagation, here’s the second installment, on growing plants from cuttings. I meant to publish this ages ago. Sorry about that.
Propagation from cuttings is easier, I find, than from seed (at least, it was before I tried winter sowing). Lots of plants root easily from cuttings. Here’s how you do it.
1. Remove a section of stem, perhaps 4-6 inches long, from your plant of choice. Here, I have taken cuttings of some unknown variety of pink chrysanthemum. Cut off the flower, if there is one.
2. Strip the lower leaves off the cutting, leaving about 2 inches of bare stem.
3. (Optional) Dip the end of the cutting into a small bit of rooting hormone. Rooting hormone is easily found at garden centers, and comes in powder and gel form. Don’t dip the cutting directly into the container; doing so will contaminate the rest of the rooting hormone. But it’s not absolutely necessary to use rooting hormone. Some plants will root just fine without it.
4. Fill a squeaky-clean pot with your choice of potting medium (potting mix, coir, perlite, etc.) Moisten the mix thoroughly. Using a pencil, chopstick, or your finger, make a hole in the dampened growing medium in your pot.
5. Insert your new cutting gently into the hole, taking care not to remove much rooting hormone in the process. Use the pencil or chopstick to gently firm the soil around the cutting.
6. When your pot is full, water the cuttings either from the top or bottom. Personally, I prefer bottom-watering, wherein you place the pot in a shallow bowl of water and let the water wick up through the drainage holes. Don’t leave it too long–just until the pot feels a bit heavy; maybe 15 minutes.
7. To elevate the humidity levels around the plant (important while the cuttings are forming roots), you can cover the top of the pot with plastic wrap, a plastic bag, or (my favorite), a cheap shower cap from the dollar store (they come in multi-packs and you can rinse and reuse them). Poke a few drinking straws into the pot to prop up the plastic; you don’t want it touching the surface of the leaves. Cut a couple of slits in the plastic to allow a bit of air to circulate; this will stanch mold development (alas, you won’t be able to use the shower cap for its original purpose). Or, you can leave it untented, but you must be more vigilant about watching the pot’s moisture level.
8. Keep the potting medium just moist, not wet. The classic comparison is that the soil should feel as moist as a wrung-out sponge. Check it regularly until you get a sense for how rapidly moisture evaporates from your medium.
9. Make sure the pot has adequate light. You can grow the cuttings under fluorescent lamps, or if you’re lazy like me, you can stick the pot outside and let the cuttings work with the elements. In the winter, this approach won’t work with tender cuttings, like those of houseplants or summer annuals, but hardier plants do just fine. These chrysanthemums spent the winter outdoors with no shelter at all.
10. You’ll know when the cuttings have rooted when they resist a gentle tug. Please don’t check them too often, or you will defeat the process. Patience is essential. Give them a solid 3 weeks, at least, or if you take cuttings of hardy plants in the fall, let them sit around all winter. I’ve propagated chrysanthemums, lavender, rosemary, Carolina jessamine, and Artemisia ‘Powis Castle’ using the leave-it-to-the-elements method.
At the end of this document is a list of plants that reproduce easily from cuttings. Give them a try!