08 December 2011

Hardwood cuttings taken in winter make next year's perennials

Making more plants from cuttings provides duplicates of your favorite garden specimens and hours of indoor gardening fun. Watching plants take root and grow is rewarding.

Hardwood cuttings are taken from trees and shrubs during early winter months and can be grown outside or in a cold frame.

Winter hardwood cuttings are not taken from the tips since they are to be grown outside and tip growth is easily damaged. Tip cuttings can be grown inside with heat where the conditions simulate early spring.

Some of the many plants that are good candidates for winter hardwood cuttings include: Barberry, Boxwood, Callicarpa (Beauty Berry), Campsis (Trumpet Vine), Caryopteris, Chaenomeles (Flowering Quince), Cotoneaster, Crataegus (Hawthorn), Cytisus, Deutzia, Forsythia, Fothergilla, Hedera (Ivy), Hibiscus syriacus (Rose-of-Sharon), Hydrangea, Ilex (American and Japanese Holly), Kerria, Lagerstroemia (Crapemyrtle), Ligustrum (Privet), Lonicera (Honeysuckle), Osmanthus (Holly), Parthenocissus (Virginia Creeper), Philadelphus (Mock Orange), Roses, Rubus (Blackberries), Skimmia, Spirea, Staphylea (Bladdernut), Syringa (Lilac), Taxus (Yew), Viburnum, Vitis (Grape), Weigela, and Wisteria.

If your goal is to plant a large area, trees that easily root from ¼ to ½ inch thick cuttings include willow, dogwood, and poplar. Information at USDA link http://tinyurl.com/7tgkeqw.

A 4-to-6-inch long stem cutting is made early in the morning, where this year’s growth meets last year’s growth. If time does not allow cleaning and planting the cuttings immediately, put them into a plastic bag with a moist paper towel and store them in the refrigerator.

Horizontal shoots will not produce as nice a plant as vertical, terminal shoots. Shoots closest to the roots of the parent plant will root best and healthy plants produce the most successful cuttings. Roots will grow only on the earth end of the cutting so mark cuttings with a pen so you will know which end is up.

Prepare the planting containers. Fill a large pan or several small growing pots with peat moss and perlite or coarse sand. Water and drain several times. When the planting medium is saturated and drained, make planting holes with a pencil.

Remove all but the top 3 leaves from each cutting. The top cutting is made at an angle. The bottom cut is made just below a leaf bud or node.

Without cutting into wood, make a wound in the stem by cutting or scraping away a small strip of the outer bark, exposing the green cambium layer beneath. Roots develop along the wound.

Dip the base of the cutting into rooting hormone/auxins for a few seconds.

Plant the hormone treated portion of stem in the prepared pots. Firm the soil around the cutting with the top of the cutting visible. If the cuttings blacken, remove and start again.

Cuttings taken from cold hardy plants will remain dormant outside all winter. Remember to keep the soil damp but well drained. Slow growing plants will take longer to produce roots and rapidly growing plants such as grapes and forsythia will show roots fairly quickly. 

When plants have the same amount of above-ground and below-ground growth, they are ready to be moved into containers. They are tender and should be checked a couple of times a week, if not daily. Slow growing cuttings will be ready to plant in the ground next fall.

Bundles of cuttings can be hormone dipped, placed in a shallow box and surrounded with sand. Keep the container about 45-degrees. Over the winter the cuttings will form a callus where roots will form when they are planted in a shady spot next spring.

Turning hardwood cuttings into landscape plants is a fairly easy and low cost hobby.

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