Many deciduous shrubs in the home landscape may be propagated by softwood cuttings. Shrubs that can be propagated from softwood cuttings include lilac, forsythia, weigela, dogwood, ninebark, and viburnum.
Time of Year to Take 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.
Rooting Media & Containers
A proper rooting medium is needed to successfully root softwood cuttings. The rooting medium must retain moisture, but also drain well and provide physical support. Coarse sand, perlite, and vermiculite are good rooting materials.
The container which holds the rooting medium should have drainage holes in the bottom. If only a few cuttings are desired, a large clay or plastic pot would be adequate. A plastic flat may be used when rooting larger quantities. Once the container has been filled, the medium should be watered and allowed to drain before the cuttings are inserted.
Reducing Water Loss is Important for Successful Rooting
Water is critical to the survival of the cuttings. A cutting has no root system to absorb water in the initial stages of the rooting process, yet continues to lose water through its foliage. The cutting will wilt and die if it loses a large quantity of water. Water loss can be reduced by inserting several stakes just inside the wall of the container and then placing a clear plastic bag over the cuttings and container. Flats can be covered with clear plastic domes.
Rooting Hormones are Beneficial
While cuttings from some shrubs root easily, others are more difficult to root. Root-promoting substances 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 are often available in garden centers. Most products are in powder form.
Steps for Taking Softwood Cuttings
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), then dip the base (cut end) of the cutting into the root-promoting substance. 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 rooting medium and let it drain for a few minutes. 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 should it begin to dry out. Rooting of most deciduous shrubs should occur in 6 to 8 weeks.
Care After Rooting
Examine two or three cuttings after 4 to 5 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 root growth. 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 commercial potting mix. The young plants can be planted in the ground in early fall. 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 the rooting of cuttings and growing of young plants to be fun and rewarding.
Updated from an article that originally appeared in the June 7, 2019 issue of Horticulture and Home Pest News.