Propagation medium influences success of sweet fern [Comptonia peregrina (L.) Coult.] rhizome cuttings.
There is a desire to increase the use of native plants for landscaping as alternatives to exotic species, some of which are invasive. Sweet fern (Comptonia peregrina (L.) Coult.), is a low-growing, ornamental shrub, native to northeastern North America. It is a prime candidate for development as a landscape plant due to its adaptability to dry, infertile soil with full sun exposure that characterizes many landscape situations. Research to improve sweet fern propagation by rhizome cuttings was conducted. Autumn-collected, dormant rhizomes were cut into 5 cm long pieces and planted in 160 ml square pots in four different propagation mediums: Scotts Metro Mix 510 Growing Medium; horticultural grade perlite; horticultural grade vermiculite; and mason's sand. Pots were maintained in a dark cooler at 5°C±2°C for 90 days before being moved into a warm greenhouse for forcing. Vermiculite pots had 100% survival, while pots of Metro Mix 510, perlite and sand had 81%, 81% and 6% survival, respectively. Vermiculite pots produced the greatest number of shoots per pot (4.2) and total shoot length per pot (14.8 cm), but were not statistically different from Metro Mix 510 pots. Young plants were grown for 120 days in 4:2:1 aged pine bark:sphagnum peat moss:sand growing medium with controlled release fertilizer and were potted to larger containers once. At the end of the 120 days of growth full, well-established plants were produced. Following an overwintering period and leafing out plants were 67 cm tall and 59 cm wide, and had between three to six basal shoots.