Vanda

Vandas are epiphytic, tropical herbaceous perennials in the orchid family (Orchidaceae). It is native to the tropical and subtropical regions of Asia and the Pacific. In their native habitat, vandas grow on trees, shrubs and rocky outcrops in wet or seasonally dry forests. The genus name is the Sanskrit name for one of the species.

As cultivated plants, vandas grow best in bright, indirect light, ideally a south-facing window or a bright greenhouse.  For strap-leaf species and hybrids (see below) 3,000 to 5,000 fc should be sufficient (full, direct sunlight is approximately 10,000 fc by comparison).  In warm climates, they enjoy being outdoors during the summer in dappled sunlight. They require high humidity and may need multiple waterings per day in summer months. Use a quick-draining, fast-drying medium such as kiln-fired products, lava rock, coarse potted bark, or an open basket with no medium at all. Vandas put out numerous, thick, aerial roots that cannot be confined to pots. The roots should not be trimmed, as they are vital for taking up nutrients and water and for photosynthesis.

All vandas have monopodial growth, meaning they grow upright from a single stem, producing new leaves every year. Flower spikes emerge from the axils of the leaves. The flowers are usually large, long-lasting and showy, with small lips. Some species (and their hybrids) are fragrant. 

There are 90 species of vanda in nature, from which thousands of hybrids have been created. Most of the plants in the nursery trade are hybrids. Vanda has been crossed with related genera to produce intergeneric hybrids such as Aeridovanda (= Aerides × Vanda), Aranda (= Arachnis × Vanda), Hawaiiara (= Renanthera × Vanda × Vandopsis), Holttumara (= Arachnis × Renanthera × Vanda), Renantanda (= Renanthera × Vanda) and Yapara (= Phalaenopsis × Rhynchostylis × Vanda). Hybrids previously known as Ascocenda (= Ascocentrum × Vanda) are Vanda because the genus Ascocenda is now treated as a synonym of Vanda. These hybrids are popular, as the former Ascocetrum species (V. ampullacea and V. curvifolia) imparted bright colors and a dwarf habit to their hybrid offspring. The intergeneric hybrid Mokara (= Arachnis x Ascocentrum x Vanda) is a popular outdoor bedding plant in the tropics, but it is now included in Aranda (= Arachnis × Vanda). 

Species with pencil-like, terete (round in cross-section) leaves were formerly included in the genus Vanda and much used in vanda hybrids, namely the semi-terete hybrids. They are now placed in the genus Papilionanthe. Their hybrids with Vanda are Papilionanda.

Quick ID hints:

• Erect, upright growing stem
• Linear, folded leaves with a leathery feel
• Thick, waxy, brightly colored flowers with large tepals and small lips

Insects, Diseases, and Other Plant Problems:  Most of the diseases affecting vandas are rots related to excess water being allowed to stay on the leaves and flowers or when poor drainage is present. Thrips can destroy flower buds while the buds are still enclosed by bracts. 

VIDEO Created by Laura Barth for "Houseplants, Succulents, and Cacti", a plant identification course offered in partnership with Longwood Gardens.