Miniature pine tree (Crassula tetragona) is a low-growing succulent shrub resembling a small pine tree, boasting a tree-like habit of bluish green, awl-shaped leaves and spring-blooming white flowers. A popular bonsai, miniature pine tree is often grown as a potted garden plant or houseplant, though it may also be grown directly in the garden where hardy. Aesthetically, miniature pine tree fits in well with rock gardens, bonsai plantings and zen-themed gardens.
A native of South Africa, miniature pine tree is a heat-loving frost-sensitive plant, hardy to about 28 degrees Fahrenheit. It may be grown successfully outdoors in U.S. Department of Agriculture plant hardiness zones 9 to 11, where it will thrive in full sunlight or light shade. Provide indoor plants a winter dormancy period with temperatures around 48 degrees Fahrenheit.
Like other succulents, miniature pine tree requires very well draining soil. Poorly draining soil, coupled with excessive irrigation, is a surefire recipe for the often fatal fungal disease root rot. A mixture of sand, loam, pea gravel and peat moss with a pH between 6.1 and 7.8 is ideal. Fertilize once during the growing season with a balanced 10-10-10 fertilizer diluted with water to about half strength.
The low maintenance miniature pine tree requires water only once a month or so during the growing season, watering deeply, then allowing the soil to completely dry out before watering again. In the winter, water sparingly, just enough to keep the leaves from shriveling. Miniature pine tree may be propagated by leaf or stem cuttings, rooted in moist, well-draining potting media. The plant may also be divided during the growing season or grown by seed.
Members of the Crassula genus are prone to mealybugs -- small, cottony insects that form colonies on leaves. If left unchecked, they may stunt plant growth or invite unattractive black sooty mold. The University of California Integrated Pest Management Program recommends removing mealy bugs with a direct stream of water or applying insecticidal soap or narrow-range oil. Avoid excessive use of insecticides in the home garden, which can kill the beneficial insects and parasites that prey on mealybugs.