Helichrysum petiolare, commonly known as liquorice plant, grows half a foot tall with a trailing, draping growth pattern, making it ideal for hanging baskets, walls and as a ground cover. A frost-tender perennial, Helichrysum petiolare grows in U.S. Department of Agriculture plant hardiness zones 9 through 11. Gardeners often grow the plants as annuals in cold climates or overwinter then indoors.
Propagating from Stem Cuttings
A stem cutting, taken from a mature Helichrysum petiolare plant, develops roots in the right environment. Once established, the cutting grows into an identical clone of the parent plant. Helichrysum seeds germinate reliably but, as with many cultivated varieties, the seeds often grow into a plant different from the parent plant. To grow an identical plant, propagate it from stem cuttings. Select springy green wood in early to midsummer to have a new plant ready for the following spring.
Rooting the Stem Cuttings
Take a stem cutting 3 to 6 inches long. Make the bottom cut just below a leaf node at a 45 degree angle. Make the top cut at a horizontal angle. Remove the leaves from the bottom of the cutting leaving the top set of leaves. Insert the bottom 1/3 to 1/2 of the Helichrysum petiolare stem cutting into a pot filled with soilless rooting media. Roots develop in two to four weeks at 21.1 degrees Celsius. Transplant it out the next spring after the last frost.
You can grow Helichrysum petiolare as an annual in climates outside its growing region from seed or starts each spring. Start the seeds in a greenhouse or an indoor area six to eight weeks before the last frost date in your growing region. Germinate seeds in damp soil between 20 and 30 degrees Celsius. If the propagation area regularly falls below the required temperature range, use a heating pad, available at garden centres, to regulate soil temperature.
Planting Out and Overwintering
Plant rooted cuttings and seed starts out in spring after the last frost date. Helichrysum petiolare plants grow well in full sun or partial shade. Poor, rocky or sandy soil makes ideal conditions as long as the area drains well. Helichrysum petiolare suffers in wet, clay like or waterlogged soil. To overwinter, plant in hanging baskets or pots, or lift the roots from the soil in the fall and transplant into indoor containers for the winter.