A callus often develops at the base of a cutting at the site of a wound, when conditions are good for rooting. A callus will look like a knot or knuckle growing at the base of a cut stem or leaf.

This pepper cutting has developed a knuckle-like callus at the base of the cut stem; crown roots will soon develop.
PC: Leslie F. Halleck

Some plants will develop a callus and adventitious roots simultaneously, while other plants must first develop a callus first, before new roots can grow.

Learn more in my plant propagation book PLANT PARENTING

Many plants can generate new root tissue (adventitious roots) and new shoot tissue (adventitious shoots) from other parts of the plant such as a stem or leaf. Once the new roots and shoots form from the existing plant tissue, a new identical plant clone develops. The resulting new plant will identical to the mother plant from which you took the cutting.

I accidentally broke this piece of African violet crown away from the rest of the plant. I supported it in water and rerooted the crown, making a new clone of the mother plant.
PC: Leslie F. Halleck

Mother plants are so named simply because it provides the material to grow the new baby plants.

Learn more in my book PLANT PARENTING

Nigella seed pods are quite beautiful and easy to collect; and the bounty of dark black seeds spread easily around the garden without your help. Ok, so they can spread all over the place in sunny locations! But they are beautiful and are one of my favorite wildflower seeds to collect.

PC: Leslie F. Halleck

Nigella is a example of a perfect flower - one that has both male & female parts, thus able to self-pollinate. Allow these fanciful seed pods to dry completely on the plant for seeds to be mature. Seed pods will turn completely tan or brown when ready.

Fun Fact: Nigella seeds are edible! Many people use them as a seasoning.

Many succulents can generate new root and bud tissue from the base of a fallen leaf. The leaf will typically form a callus, and then new adventitious roots will form, followed by an adventitious bud and new shoot.

Different stages of succulent plant development.
PC: Leslie F. Halleck

Above, a fallen echeveria leaf develops new adventitious roots at its base, followed by an adventitious bud and shoot, which then develop into a clone of the original mother plant. Cool!

If you want to learn more about plant propagation, and all the different types of cuttings you can take to make more plants, check out my book PLANT PARENTING

Certain plants, such as the popular houseplants peperomia and begonia, can develop new roots and buds on the leaf petiole and even from the veins along the leaf itself. These types of plants are masters of multiplication and can be propagated in a number of different ways.

New adventitious roots and a bud and shoot have developed at the base of this peperomia leaf petiole.​
PC: Leslie F. Halleck

If you look closely at the photo, you'll see a new adventitious roots and a new tiny bud shoot developing. This will turn into a new baby clone plant! However, don’t expect your tomatoes or citrus plants to sprout new roots from just a leaf; the cells in their leaf and petiole tissue can’t grow new root or shoot tissue.You'l need to get to know how your chose plant can, and can't, make new roots and shoots from cuttings.

Learn more about how to take these plant cuttings in my book PLANT PARENTING

New adventitious roots and buds can develop at the base of a leaf, leaf petiole, stem internode, node, or at the base where a stem has been cut, depending on the plant species. Have you ever been instructed to plant tomatoes deeper in the soil so that you bury part of the stem? That’s because tomatoes grow adventitious roots along their stems, which can make the plants stronger and more vigorous.

Adventitious root initials developing on this tomato stem.
PC: Leslie F. Halleck

You can clearly see the adventitious roots growing along the stems of this potted tomato plant. These stems are good candidates to provide cuttings, since root tissue is already growing.

To learn more about how to take cuttings, and make more tomato plants, check out my book PLANT PARENTING

Can't get enough Chinese money plant (Pilea peperomioides)? Me neither! Luckily this beautiful houseplant is a prolific producer of baby plants, all on it's own.

Chinese Money Plant
One of my lovely Pileas perched in a window
PC: Leslie F. Halleck

Pilea can be propagated by removing these offsets, or pups, that grow from the base of the main plant stem. These pups develop their own roots and can be cut away from the mother plant and potted up.

Want to learn how to take these clone cuttings...and all sorts of other types of cuttings? Be sure to pick up my book PLANT PARENTING

Seeds of succulents and cactus can vary dramatically in size, shape, and hardness. Some are soft and barely bigger than a speck of dust (Lithops spp.), while others are large with hard seeds coats that require scarification (Tephrocactus spp.).

PC: Leslie F. Halleck

The size of your plant's seeds will determine how you sow them and how deep you plant them. Teeny tiny seeds can be planted using a seeder tool, which helps you plant tiny seeds at the correct spacing, without wasting or losing seeds!

Learn all about seeds and special germination techniques in my new book PLANT PARENTING