Can You Overwinter Alternanthera Red Threads Indoors?

Characteristics

• "Red Threads" has fine, needle-like leaves that encircle its short, delicate stems. The plant is only 6 or 8 inches tall, but usually spreads to cover an area of 1 foot or more. It flowers in late fall through winter, but its flowers are tiny and form in the leaf axils, the spots where leaves originate from stems, so they are quite inconspicuous. "Red Threads" makes a good addition to a mixed bed or border, and does well in a hanging basket or other container on a patio or porch. It responds well to surface clipping and is a traditional part of a clipped, formal planting such as a knot garden.

Winter

• "Red Threads" is a frost-sensitive, tropical plant that's quickly killed by sub-freezing temperatures lasting for more than a few hours. In the coldest part of its range, where winter temperatures can drop below freezing for brief periods, its foliage may be damaged by cold, but its roots can survive. In areas with colder winters, you can overwinter "Red Threads" by bringing potted specimens indoors, locating them in a sunny, south- or west-facing window, but protect the plant from any cold, drafty windows or doors. If you grow "Red Threads" in the ground, dig up a plant or two and pot them in commercial potting soil to bring indoors, watering the plant well to prevent wilting.

Taking Cuttings

• "Red Threads" also grows well from cuttings taken in fall, before frost arrives. Choose young, healthy stems and use sharp scissors or a knife to remove 4- or 5-inch long cuttings from their tips. Pot these in moist, sterile potting soil in containers with drainage holes and keep them in a warm spot in filtered, indirect light until the cuttings root and show new growth. You can speed this process by moistening and dipping the cut end of each stem in rooting hormone, which is available at nurseries and garden centers. Once cuttings are growing well, move them into a brighter spot, where you can keep them until the following spring.

Spring

• Move "Red Threads" plants back outdoors in spring, when the risk of frost has passed and the soil has warmed to about 60 degrees Fahrenheit. Spring is the best time to divide any larger plants from the previous season. Use a sharp spade or knife to cut through the center of the plant, gently pulling the roots apart that are attached to each division. The plant prefers a spot in full sun, where it develops its best leaf color, but can also grow in partial shade. It thrives in any type of well-drained garden soil but dies quickly when grown in a wet, soggy spot. If your soil is rich in clay and drains slowly, add sand at planting to improve its drainage.