Terrestrial orchids do not grow on trees like their epiphytic relatives. They are ground-dwelling plants that can be grown in home gardens. Being pseudo-bulbs, they are often listed as corms, tubers or rhizomes instead. When viewing them, you might assume they are woodland plants. While they do like humus-rich soil, they prefer drier, sunnier conditions. Purchase them as bulbs or plants, since propagating from seed is tricky.
Chinese Ground Orchid
Hardy in USDA zone 6, Chinese ground orchid (Bletilla striata) is a rare beauty for the temperate garden. Though they grow taller in their native habitat, in the garden these hardy orchids can reach 1 to 2 feet tall. Plant the corms in spring along with your other summer bulbs. The flowers may not develop until the following spring. This plant spreads by rhizomes, eventually forming a dense clump. The species flower is reminiscent of the orchids florists use to make corsages. Each flower is only 1 to 2 inches across. The leaves are bright green, strap-like, and have vertical pleats throughout them. New varieties of this ground orchid have been developed to provide larger blooms, with different flower colors (white, pink or purple). They prefer full sun and do not bloom well in complete shade. Provide well-draining soil, since soggy conditions can cause the corms to rot. Wait to water your orchids until the soil is dry.
Golden Chinese Ground Orchid
The golden Chinese ground orchid (Bletilla ochracea) is a yellow form of hardy orchid. The sepals are pale yellow, and the lip can range from lavender to deep gold. A more common strain is the Chinese butterfly ground orchid; its sepals are also pale yellow, but it has a deep golden lip covered in purple speckles. This orchid can tolerate full sun in Northern climates, but needs sun protection in Southern gardens. If you are in a hot region, provide it with morning sun and afternoon shade. Golden orchids reach up to 20 inches tall, and each bulb will develop two pleated linear leaves. Golden orchid will bloom in early summer, a bit later than Bletilla striata. This orchid is hardy in USDA zone 7.
The Taiwan orchid (Bletilla formosana) is another hardy species orchid. Though a little more tender, strains found at higher elevations are cold-hardy to USDA zone 8 gardens. Taiwan orchid has pale pink to-lavender flowers (occasionally white). The pleated leaves and sturdy stalk can reach up to 2 feet in height. This orchid is suspected of cross-pollinating with Bletilla ochracea, causing unusual pink and yellow color variations.