Propagating Trees: Taking or Making a Root Cutting

Process

• Most softwood root cuttings can be made in the late spring through early summer. For hardwood cuttings, the BBC Garden Guides website recommends taking cuttings during the cooler seasons, primarily between September and March. After pulling up as much root as reasonably possible from the plant you wish to propagate, cut away sections of the root ranging from 1/2 inch in length to 3 inches. Thicker roots lend themselves to shorter, stubbier cuttings, while thinner ones may need more length to provide enough raw material for a new plant to grow.

Wood Hardness

• Many kinds of trees can thrive from root cuttings, though some of them will propagate more readily if the cutting occurs at a particular stage in the tree’s development. According to the University of Arkansas Division of Agriculture Research & Extension, most trees propagate more successfully from root cuttings taken from a relatively young specimen in the softwood or semi-hardwood stage of growth. Some plants remain in this stage for only a brief window of time. However, oak and pine trees go through several softwood stages per year, and red maples continue to grow all year long.

Rooting Hormone

• You can encourage the growth of your root cuttings by treating them with a rooting hormone. Softer woods that root more easily require lower concentrations of rooting hormone than older, harder woods. Many of the liquid “dips” or dry hormones sold in garden stores contain a concentration of 1,000 parts per million, which works well with softer woods, but particularly stubborn varieties may require products with concentrations of up to 15,000 parts per million.

Considerations

• Think about what kind of trees you want to grow before setting out to propagate them from root cuttings. Some species of trees grow more readily from cuttings than others. Colorado State University Extension names willows, red twig dogwoods and poplars among the easier trees to propagate in this manner, while oak and pine trees can prove more difficult despite their frequent softwood stages. If you have trouble getting certain kinds of trees to propagate successfully from root cuttings, you may have better luck growing them from branch cuttings or seeds instead.