Calcium Requirements for Vanda Orchids

Vanda Orchids

• Vanda is a genus in the orchid family with about 50 species. The American Orchid Society describes three types of vandas: strap-leaved, semi-terete and terete. Their leaves are flat and broad, cylindrical or semicylindrical. Vandas bloom every few months in colors ranging from yellow-brown to burgundy red shades. Flowers last several weeks. All vanda orchids are heavy feeders. They absorb calcium and other nutrients from the atmosphere through their long trailing root system.

Fertilizer Requirements

• Calcium is included in most balanced fertilizers. Vanda orchids thrive when fed balanced fertilizer once a week during warm weather, or in a one-quarter strength solution at each watering. Feed vandas once every two to four weeks during cool or cloudy weather when their growth slows. Water the plant before applying fertilizer. Organic liquid fish emulsion fertilizer is a source of calcium.

Micronutrients

• Vanda orchids growing in the wild derive their calcium and other micronutrients from the tree they grow on. Potting medium such as coconut fiber, bark chips, tree fern fiber and leaf mold contain minute amounts of micronutrients. Additional calcium and micronutrients are available through water. Vanda orchids also receive micronutrient content from bird droppings in their native tropical habitat.

Light Requirements

• In addition to calcium and other micronutrients, the vanda genus of orchids has unique light requirements. They thrive in warm weather and full sun or partial shade. In cold winter areas, they grow outside in summer and at a sunny window during winter. A minimum temperature of 55 degrees Fahrenheit at night and maximum 95 degrees Fahrenheit during the day is recommended. Vanda leaves develop medium-green color when they are given adequate light.