There are two basic ways that plants can be propagated. Sexually and Asexually. Sexually is through seeds. Asexually involves several other ways, such as cutting, grafting, layering, division, and a few other methods. Propagation through cuttings is an inexpensive way to create clones of a plant you already have.
What do you need to propagate through cutting? Not much. A growing medium, a sharp knife or scissors, and potentially rooting hormone, which usually costs in the $5-$10 range. I would add a container to root in, but any old recycled container will do, like an old plant flat, an egg carton, or a yogurt container. Just wash and sanitize the container first, especially if it contained plant matter before.
Cuttings work on certain plants better or more quickly than others. They generally take best in the spring, but can be started any time of year. Cuttings work best with new/green growth, but are possible with older/woody growth. To stack the odds in your favor, you may wish to start with an easy plant to propagate and with new growth from that plant. I’ve found several plants to be very easy to propagate: Lavender, rosemary, thyme, and tomatoes are all fairly easy to root. I’ve rooted all of these plants without using rooting hormone in the past. I’ve also propagated blueberries without rooting hormone, but it was with new growth in the spring (so the odds were in my favor).
The general process to propagate through cutting is pretty simple. Cut new growth with a sharp blade, preferably at an angle and not straight across. Tear off lower leaves to expose the stem. If using, put that lower stem in rooting hormone powder. Stick stem into a growing medium (Coco coir, peat moss, potting mix, etc.). Keep medium moist and the cutting in indirect light until you notice new growth, usually after a few weeks. If you are unsure if there is new growth after a few weeks, you could give the plant a gentle tug, if you feel resistance to the tug, that is the roots that have formed in the growing medium.
Once the cuttings are established, treat them like seedlings. Don’t stick them right in the ground immediately, but harden them off by gradually exposing them to the outdoors, preferably on mild days or during morning/evening hours when the sun isn’t at its strongest (if it is in the summer). After harding off, the plants are ready to go. At this time you can either put them in the ground or repot them.
Now those instructions are for the proper way to produce through cuttings and will give you the best chance for success. There are even simpler ways that have worked for me. I’ve pinched new growth from lavender, plucked off the bottom leafs and stuck it directly into the ground, and it has taken. I’ve also done this in the spring with blueberry bushes, where I’ve stuck them right in the ground and they’ve managed to root. Both of these examples were with no rooting hormone and no growing medium. But in these cases I think it’s safe to say I had luck on my side. If I really want to be sure roots take, I follow the process outlined in the directions and increase the odds of success.
Good luck with your cuttings! Let me know if these methods work for you, and what you used it for!