Have you had the experience of transplanting an Oriental poppy or butterfly weed (Asclepias tuberosa) to another part of the garden and later found these plants coming up again in the places where you had removed them?
It is almost impossible to get every bit of the root system. The pieces of roots that are left can send up new top growth even though not a shred of the plant’s crown is left.
These two plants are among the ones that can be started from root cuttings.
Not all plants have the kind of roots that can be started in this way, but for those that can, it is a simple and easy way to increase plants and gives us a very satisfactory method of plant propagation.
The plants produced from root cuttings will be like the parent plant, with a few exceptions.
For example, variegated plants cannot be depended on to come true, and in the case of grafted plants, the new plants will be like the understock and perhaps have almost no garden value.
Root Cuttings Taken in Fall
Root cuttings are often taken in the fall (or in late summer from plants such as fern leaf peony and Mertensia that mature earlier).
They develop calluses during the winter and tend to produce leaf buds. Fibrous root cuttings from phlox or chrysanthemum are also made in the spring.
The cuttings of hardy plants are started outside under controlled conditions—that is, in a frame in a well-drained location where they can be watched carefully, kept weeded, and mulched. Flats or flower pots could be used if only a very few cuttings are to be started.
A sandy soil is desirable. There is less danger of the root cuttings decaying, and a better root system is developed. This could be loam and sand, peat and sand, or a mixture of sand, soil, and peat.
Dig the entire plant to obtain the cuttings if a great many are wanted. If only two or three are needed, they can probably be obtained without much disturbance to the plant by thrusting a sharp spade down close beside the plant and prying outward away from it.
The roots are cut into lengths of 2” to 6” inches and spaced 2” inches apart.
Thicker root pieces, such as from the Oriental poppy, can be placed vertically. The thick end (the part coming from nearest the plant’s crown) should be uppermost.
If the top end of the cutting is cut straight across and a sloping cut is made across the basal end, no mistake will be made in planting.
Set and Plant Cuttings
Set the cuttings one-half to one inch deep. One authority recommends that when planting cuttings with fleshy roots such as plume-poppy (bocconia), bleeding-heart, shooting star (Dodecatheon meadia), baby’s-breath, beebalm (monarda), peony, and Oriental poppy to let the upper ends protrude half an inch instead of covering entirely.
I have never experimented with this method but would shade the cuttings with burlap. A glass jar over each cutting might be helpful.
Perhaps some readers have tried this method and could tell us the exact procedure and the results to be expected.
The thinner roots taken from such perennials as phlox, Japanese anemone, gaillardia, hardy salvia, stokesia, and verbena are usually cut into pieces two inches long and laid horizontally.
Perennial phlox has some smooth and stringlike roots and others with much branching of finer roots.
We are told that the smooth stringlike roots are preferable to the whiskery ones for root cuttings. Other perennials that can be started from root cuttings include achillea `The Pearl,’ mullein (Verbascum), and Italian bugloss (Anchusa italica).
Press the cuttings firmly into the planting medium and cover them with an inch of sand or another planting medium.
Water thoroughly. In late fall, mulch with light, loose material. Oak leaves or Excelsior are good.
Shoots Appear in Spring
Shoots should appear in the spring. If planted in a frame, they can be left for a year unless they become too crowded.
If planted in flats or flower pots, transplant to nursery rows when the new shoots are 2” to 3” inches high.
They should be reset with the same care as any other plant—watered and shaded until established and kept free of weeds.
Shrubs and trees that can be started from root cuttings include wisteria, Xanthoceras (sometimes commonly called hyacinth-shrub because of the resemblance of its blossoms to large hyacinths), hypericum, crape-myrtle (Lagerstroemia), locust (Robinia), and golden rain tree (koelreuteria).
To obtain roots of trees or shrubs, dig down about midway between the outermost branches and the main part of the tree or shrub to obtain the best roots for propagation.
If there are several kinds nearby, ensure you get the roots from the plant desired for propagation.
44659 by Olga Rolf Tiemann