How to Propagate Outdoor Plants
Stretch your gardening dollar by propagating outdoor plants. You can grow more of your favorite plants with seeds, cuttings, division and layering techniques.
You can be frugal in the garden—double (or even triple) your favorite landscape plants for free with propagation. Some plants can grow an entire new plant from stem cuttings, while others provide seeds for replanting. Once you know the right techniques, filling in empty spaces in garden beds is a breeze.
Propagating From Seed
Many annuals and biennials come from seeds. When collecting seeds from existing plants, collect seed heads only in dry weather. Keep seeds in a cool place, and store in paper rather than plastic bags. Sow seeds in flats in spring and transplant individually when they reach sufficient size. Be sure to keep seedlings moderately moist during germination and when they are still fledglings.
Propagating From Cuttings
Outdoor plants like nonpatented sedums, boxwoods, Plectranthus, and feverfew are propagated by snipping cuttings. This method is especially handy for hybrids that might not continue their parents’ traits if grown from seed. In late spring or early summer, when the new growth of a plant is no longer soft and tender, cut a sprig 2–3 inches long. Remove the lower foliage and reduce large leaves by cutting the leaf in half. To increase success rates, dip the bottom tip of the sprig in rooting hormone. Insert the lower third of the cutting in potting soil and firm the soil around the stem, then place the cutting in a shady spot and water regularly.
Dividing Outdoor Plants
Many perennials (especially bee balm, Shasta daisies, irises, and ornamental grasses) benefit from periodic dividing to prevent overcrowding and to rejuvenate their strength. Dividing also creates color echoes in your garden for continuity. Divide during a rainy, cloudy period, or shade the newly planted division with draped cheesecloth to protect it from sun. Dig the whole plant, tease apart divisions with ample roots, and plant each section in new positions. Or dig a portion of the plant with ample roots and pull it free from its parent. Dig a generous hole to receive the division and backfill soil firmly around it. Water the new division into place and keep the soil moderately moist until established.
Layering Outdoor Plants
This is a slow method of propagation that works best for hardwood cuttings such as hydrangeas, rhododendrons, viburnums, and junipers. Dig a trench beside the parent plant. Then, bring a long branch to ground level, cover it shallowly with soil, and place a brick on top of the buried section. Water it regularly. This method might take a year before the sprig is sufficiently rooted to transfer elsewhere. But maintenance is minimal. When roots have sufficiently developed, clip the rooted branch from its parent and plant in its permanent position.
Country Gardens Summer 2018