What Are Some Plants That Grow Very Slowly?

Cycads

• These palm-like primitive plants take a long time to attain maturity. Present as fossils in the Pennsylvanian era 300 million years ago, cycads have male or female cones when they flower. Stiff frond-like evergreen leaves last a long time. Sago palm is the most common cycad for gardening, grown in U.S. Department of Agriculture plant hardiness zones 8 through 11. Plants reach 3 to 10 feet tall and 4 to 8 feet wide and may cluster with age. They give a tropical effect in patios, planters, or containers and are suitable as house plants and accent plants. They prefer partial shade and are drought-tolerant. Virgin's palm (Dioon edule) reaches 11 feet tall and old plants can have a 4- to 12-inch diameter trunk. Leathery leaves can be 6 feet long. Native to Mexico and Central America, plants don't outgrow their spaces in entryways, Asian gardens or xeriscape gardens. Hardy in USDA zones 8 through 11, they also prefer semi-shade.

Succulents

• Looking like little pebbles, living rock plants (Lithops spp.) consist of paired flat-topped, highly succulent leaves with interesting color patterns on the leaf tops. These African desert plants grow very slowly to eventually form clumps, needing repotting about every five years. Usually grown as container plants because they need to be kept dry during summer and winter when they are dormant, lithops grow in USDA zones 9 through 11 but make houseplants anywhere. Combine several lithops in a 5-inch-deep container with well-draining potting mix, exposing the top 1/3 of the leaves. Many cacti have slow growth, with pincushion cacti (Mammillaria) taking decades to reach full size. These low-growing mounding plants have close spine patterns and flower freely each spring in a ring around the top of each stem. Grow them in xeriscape gardens, rock gardens or as container plants in USDA zones 9 through 11, with some variations depending on the species, or as house plants in sunny windows.

Bulb Plants

• Fire lily (Clivia miniata) has 2- to 3-foot-long strap-shaped green leaves with a sturdy 18-inch-tall flower stalk in late winter or early spring that bears a cluster of orange flowers. Suitable as a container plant anywhere or as a plant for shaded areas in USDA zones 9 through 11, fire lily grows well when potbound, and only needs repotting every three to five years. It is usually propagated by division of older plants, since seedlings take years to reach flowering size. Amaryllis (Hippeastrum spp. and hybrids) grow slowly, with long-bulbs producing stalks of showy flowers repeatedly for years. Plant them outdoors in USDA zones 8 through 10 or keep them as container plants in all zones. Some cultivars form new bulbs as they grow, and outdoor beds may need thinning after a few years.

Trees

• A recent Oregon State University study showed that slower-growing trees are also longer-lived. They use their energy to produce strong wood and for defense against environmental stresses. Japanese maple (Acer palmatum) is a slow-growing, small tree. "Tamukeyama" (Acer palmatum var. dissectum "Tamukeyama") reaches 7 feet tall and wide, and has purple foliage in summer changing to bright red in fall. "Viridis" (Acer palmatum var. dissectum "Viridis") has a weeping habit with green lacy leaves that turn yellow in fall. It grows 4 to 6 feet tall and 8 to 10 feet wide when mature but is most often around 4 feet tall and wide. Both cultivars grow in USDA zones 5 through 8. The evergreen "Green Prince" cedar (Cedrus libani "Green Prince") has irregular branching and interesting growth forms suited to Asian gardens and limited space areas. Hardy in USDA zones 6 to 9, it grows in full sun to partial shade and is low-maintenance.