Want to get more greenery without spending the other kind of green (money)? Let’s take a look at how plants make more plants in ways other than from seeds.
A number of plants can be grown from parts of donor plants by taking what are called cuttings. The cutting is simply a stem with some leaves attached that has been cut off the donor plant. The cutting is then placed in water or moist soil, and over time roots develop. Once the roots develop, plants in water can be moved to soil and in no time your new plant will be growing and sending out new leaves.
Examples:
Philodendron, geranium and coleus – cuttings can be started in water.
Pothos Ivy – cuttings can be placed in water, then moved to soil after roots develop.
Jade plant – cutting start in water or soil.
Prickly pear – can be started by simply placing pads in the soil.
By the way, cacti can also start from seeds. This is a saguaro seedling.
Spider plant – take the offshoots or baby plants and place in soil.
Aloe and agave- the main plants send off small plants from the roots, called pups. The pups can be separated and replanted. The pups of the above aloe are slightly reddish in color and are towards the lower right in the pot.
Potential science experiments/activities:
1.   Learn the plant parts for different species of plants. For example, is the pad of a cactus a leaf or stem? What is a node? What is a petiole?
2.   Can you start a plant from the cutting of just a leaf, or does the leaf need to be attached to a stem?
3.   Treat some cuttings with commercial root starting hormone and compare to cuttings from the same plant without hormone. How do they differ over time? Figure out how many plants grow from each treatment, what their value is, and how much the hormone cost. Is it cost effective?
Edit: We got some hormone rooting powder this weekend and were surprised to find out that it is quite hazardous. You might want to read the label before you buy it. Be sure to read and follow all the instructions.
4.   Do jade plant cuttings start better in water or moist soil? What about in moist sand or cactus mix?
5.   Under what conditions do spider plants send out offshoots? How old do they need to be to start making more spider plants? How big? Do they make more when they are healthy or when they are stressed? How would you test these questions?
6.   Do spider plants ever flower? What about pothos ivy, aloes or agaves? If they don’t flower, can they make seeds?
7. Do aloes/agaves make more pups when they are in small pots, large pots, or when they are planted in the ground? This would be a long term study.
Hope you enjoy growing new plants. Let us know how your experiments turn out, or if you have any more suggestions for experiments or activities.
Note:Â Most of the plants noted above can contain irritants or toxins, so keep them out of reach of small children.