Many ornamental shrubs in the home landscape may be propagated by softwood cuttings. Softwood cuttings are taken in late May through early July from the current season s growth. Cutting material should be flexible but mature enough to snap when sharply bent. Lilac, forsythia, weigela, barberry, potentilla, and viburnum are some of the shrubs that may be propagated from softwood cuttings.
A proper rooting medium is needed to successfully root softwood cuttings. The rooting medium must not only retain moisture but also drain well and provide physical support. Coarse sand, perlite, and vermiculite are good rooting materials.
The container that holds the rooting medium must have holes in the bottom for drainage. If only a few cuttings are desired, a large clay or plastic pot should be adequate. A wooden or plastic flat may be used if larger quantities are rooted. Once the container has been filled, the medium should be watered and allowed to drain before the cuttings are inserted.
Water is critical to the survival of the cuttings. A cutting has no root system to absorb water, yet continues to lose water through its foliage. The cutting wilts and dies if it loses a large quantity of water. Water loss can be reduced by placing a glass jar over the cuttings or by inserting several stakes just inside the wall of the container and then placing a clear plastic bag over the cuttings and container.
Although cuttings from some shrubs root easily, others are more difficult. Materials can be applied to promote rooting. Root-promoting substances increase the percentage of cuttings which root, shorten the period needed for rooting, and increase the number of roots per cutting. Root-promoting materials, such as Rootone, are often available in garden centers. Most products are in powder form.
When taking cuttings, remove plant material with a sharp knife. Softwood cuttings should be approximately 4 to 6 inches long. Pinch off the leaves on the lower half of the cutting. Also remove any flowers. Make a fresh cut just below the point where one or two leaves are attached to the stem (node) and then dip the base (cut end) of the cutting in the root-promoting compound. Tap off any surplus material. To avoid brushing off the powder when the cutting is inserted, make a hole in the rooting medium with your finger or a pencil. Insert the cutting approximately 2 inches deep into the rooting medium. Firm the material around the base of each cutting. After all the cuttings are inserted, water the cuttings and medium and let it drain. Cover the cuttings to reduce water loss and then place the cuttings in bright light, but not direct sunlight. Inspect the cuttings daily. Remoisten the rooting medium if it begin to dry. Rooting of most deciduous shrub species should occur in 6 to 8 weeks.
Examine a few cuttings after 3 or 4 weeks. Carefully dig up the cuttings to check on root development. If rooting is poor, simply place the cuttings back in the medium for additional rooting. When the cuttings have a well developed root system, they should be hardened off in preparation for transplanting. Remove the covering, but don t allow the cuttings to wilt. Keep the rooting medium moist. After a few days, carefully remove the cuttings and transplant into individual pots using a well-drained potting mix. The young plants can be planted into the ground in a few weeks. Gardeners may want to grow them in the garden for 1 or 2 years before moving the small shrubs to their permanent site in the landscape.
It will take several years for a rooted cutting to become a nice size plant. However, many gardeners find rooting cuttings and growing the young plants to be fun and rewarding.
This article originally appeared in the 6/6/2003 issue.
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