Purple coneflowers can be divided.

Plant Propagation

Propagating your own plants is a great way to save some money and still have a beautiful garden. Violets, begonias, coleus and ivy are particularly easy herbaceous plants to propagate by cutting. You may have already successfully started some new spider plants by rooting them in water. Many plants will root in plain water, but transferring the water-rooted seedling to soil is not always successful. You can also get good results propagating stem cuttings using a rooting medium.

Start out by cutting the stems at an angle to give them more surface area to form their roots. Most cuttings root best if the cut is made a half-inch below the leaf node. Strip the leaves off the lower parts of the stems leaving only the top leaves. If the leaves are large on top, cut them in half. It is important to use a good sterile rooting media to get plants off to a healthy start. Garden soil or compost are not good choices since they may harbor diseases. You can also purchase seed starting mixes from a local nursery.

If you use a rooting hormone, first dip the stem in the powder before placing it in soil. Rooting hormone stimulates the cutting to send out new roots. The hormone is not always necessary for the cutting to root, but it does give an advantage. After you plant the cuttings, place the pot in a tray of water. Let it soak up the water until the top of the soil is moistened and then set the pot in a bright window without direct sun. You can also place the pot in a sealed plastic bag to increase warmth and humidity, but do not let the plastic bag touch the leaves. Open the bag up for about 10 minutes each day to let fresh air circulate.

Dividing perennials is another easy and inexpensive way to gain additional plants for your garden. Dividing and replanting also controls the size of the plants and helps rejuvenate them. In general, it is best to divide spring and summer blooming perennials in the fall, and fall bloomers in spring. By dividing the plant when it is not flowering, all the plant’s energy can be expended on root and leaf growth. For fall division, allow at least four to six weeks before the ground freezes for the plants to become established, and for spring division allow enough time before hot weather. Most perennials should be divided every three to five years.

Some perennials may need to be divided more frequently or they will crowd themselves into nonflowering clumps. Your perennials probably need dividing if the flowers are smaller than normal, the centers of the clumps are hollow and dead, or the bottom foliage is sparse and poor. Several perennials like candytuft, delphinium and poppies should never be divided, but many common perennials like coneflowers and daylilies can be divided using a spade or pitchfork. Rhizomes and tubers, like irises, should by dug up and cut by hand.

Your small investment of time will pay off with many more plants for your garden. If you have a high success rate with your cuttings, the new plants can make great gifts for your gardening friends. So try increasing your plants by taking cuttings or dividing perennials. It’s fun and sometimes challenging, and you will be rewarded with a garden full of plants you propagated yourself.

Barbara Arnold is green corps coordinator at Franklin Park Conservatory.