After pruning, turn cuttings into 'parents'

3/2/2005

With a little help, pruned branches can start a new generation of plants.

Every year, gardeners at the Toledo Zoo propagate new plants from the cuttings of annuals and perennials, and on occasion, woody shrubs. "You have to be very patient with shrubs," says Rochelle Fleming, assistant horticulturist at the zoo. "Some will root easily, but some will need a bit more coaxing."

Many of the summer bloomers around the zoo grounds have been propagated over the winter, such as geraniums, petunias, Swedish ivy, verbena, begonias, and coleus.

What other plants' cuttings make good "parents"?

Some woody ornamental shrubs like crape myrtle, magnolia, oleander, azalea, jasmine, and boxwood can be started from a softwood cutting - the bright green new growth found on the tip.

Use a healthy part of a stem for hardwoods, not just the tip. You might need a cutting up to six inches long to include three or more nodes - the bumps on the stems that hold a lot of growth hormone.

Scientists say low-growing Juniperus species will root easily, but upright junipers are tougher. These narrow-leafed evergreen cuttings can be taken all year, but are best during late summer and late winter. Mature terminal buds from last season's growth will do the trick.

Wisteria, spirea, crape myrtle, and multiflora rose are commonly started by cuttings.

A plant can sprout from a stem, a stem with a shoot, a piece of a root, or even part of a leaf. We will concentrate on stems.

Find a healthy cutting at least three to four inches long. Dip the cut end into a rooting hormone.

Make a hole with the end of a paintbrush or a pencil in a planting medium such as African violet mixture or a seed-starting mix with a high quantity of pearlite, then slide the cut end of the cutting about one to two inches into that hole. Gently tap the soil around the cutting to hold it there.

Put the cuttings in rows and label them. Watering the cuttings in the container will settle the medium around the cuttings' ends. The medium should be moist, but not too wet. Think of the dampness of a sponge that has been wrung out. Water when the top of the pearlite feels dry. When the cuttings are in position, cover them with plastic sheeting to hold in moisture.

To grow cuttings, place them in a spot that is at least 65 degrees near a bright window. Leave the plastic cover on except when watering.

Once the plants start sprouting leaves in four to eight weeks, give them some fertilizer. When they have grown a few sets of leaves by summer, start setting them outside slowly to help them get used to their new environment.