Several years ago Santa Fe Botanical Garden’s Hoop House was the site of a November hands-on workshop on propagating plants from root cuttings. Bob Pennington coached and directed workshop participants in an experimental planting of a beautiful native plant – Phlox nana.
Agua Fria Nursery owner, Bob Pennington
Though Phlox nana (Santa Fe phlox) spreads by seed, it is difficult to conduct controlled propagation experiments because seeds literally explode from the seed pod when ripe for germination. Therefore, it’s futile to collect seeds before they are ready. Fortunately, the Phlox nana can also be propagated using root cuttings.
To make the experiment more interesting the group selected dormant plants brought from a garden that receives no supplemental water and from a garden that receives some extra water. It was interesting to compare the roots of the samples. Thicker, less hairy roots came from the garden receiving no extra water. One experimental objective was to determine if there would be any difference in root development and subsequent growth between the two types of cuttings.
Participants made two cuttings, starting just below the soil line, dusting half with root stimulator, half without as part of the experiment. Using clean, flat containers, each cutting was placed horizontally on top of a medium of 50/50 perlite and vermiculite, and labeled carefully, noting the pertinent details such as which garden the cutting was from and which cuttings were dusted with the root stimulator.
After placing and properly labeling the cuttings, they were covered with moistened medium and covered with a plastic lid with a hole in the top to allow for air circulation. The flat was placed in a sheltered location of the Hoop House. Because it is important to keep the medium moist, the group will take turns visiting the Hoop House throughout the winter to keep it sufficiently damp.
New root growth should appear in the spring. It is important to note that shoots can appear before root growth occurs.
Root propagation of Santa Fe phlox
Therefore, always check for root growth before gently teasing out the cutting from the medium before repotting. Pot the cuttings individually in three-inch pots filled with soil mix. Water and label. Continue to monitor soil moisture, watering to keep moist, but not soaking wet. Grow the rooted cuttings until they are strong enough to be planted outdoors.
Plant Propagation-The Fully Illustrated Plant-by-Plant Manual of Practical Techniques published by the American Horticultural Society is an excellent source of information and was used in writing this report.
Report and photos from Janice Tucker
