Native to New Zealand, Australia, and Hawaii, the colorful cordyline plant makes a striking addition to warm-weather gardens. As it's a plant that thrives in tropical climates, cordyline can't tolerate frost and doesn't do well in cool temperatures. Grown from cuttings or seeds, cordylines thrive in shade with some sunlight. In cooler temperatures, cordylines are grown indoors as houseplants.
The two most widely grown cordylines are the popular plant ti, which grows in U.S. Department of Agriculture plant hardiness zones 10 through 12, and the cabbage tree, hardy in USDA zones 7 through 10.
Soil and Spacing
The Ti plant thrives in rich, fertile, well-drained soils. Plants grow 3 to 10 feet tall and 2 to 4 feet wide and thrive when planted 3 to 5 feet apart so they have room to spread out. The cabbage tree grows slowly to 49 feet tall by 16 feet wide, with a bare gray trunk and branches topped with bushy heads of leaves. Space trees at least 20 feet apart so they have room to grow. A Cabbage tree needs good drainage, preferring sandy to loamy soils rich in organic matter. As houseplants, plant both species in a well-draining houseplant potting mix.
The moisture-loving ti plant should be kept moist while it is actively growing during spring and summer but requires less water in fall and winter. As a houseplant, the ti does best in a high humidity location year-round, such as a bathroom or on a tray filled with pebbles and water. Leaf tips will turn brown in low humidity. Cabbage trees also prefer moist soils when actively growing. The burgundy-foliaged cabbage tree cultivar "Purple Spire," needs weekly watering in hot weather.
Light and Exposure
A number of cabbage palm cultivars have either purplish-red leaves or variegated leaves. Some variegated-leaf or lighter colored varieties can scorch in direct sunlight.
Grown outdoors, the ti plant and cabbage tree thrive in shade to partial shade. Plant ti plants with more colorful leaves in a sunnier, but still partially shaded spot, with the less vivid plants residing in full shade. Houseplants need bright, indirect light, with morning sun for strongly colored cultivars.
Cordylines respond well to controlled-release fertilizers. Apply a product containing micronutrients with an N-P-K ratio of 14-14-14 every 6 months. Topdress the soil around the plant with 1 tablespoon of fertilizer for a 1-gallon container or 7 tablespoons scattered over every 10 square feet of outdoor soil surface.
Special Care Considerations
Cordylines are generally not invasive, but "Purple Tower" has naturalized into the southern United States and parts of southern California. Ti plants are sensitive to cold temperatures and shouldn't be grown at temperatures below 55 degrees Fahrenheit. Most cordylines are damaged by near-freezing weather and should be brought indoors before the first frost is predicted for your area.