The NYBG Senior Curator of Orchids says it's best to use a balanced fertilizer such as 20-20-20 in powder form to supply all the primary nutrients needed for flowering plants.

These numbers--NPK numbers--represent nitrogen, phosphorous, and potassium.  N (nitrogen) helps with vigorous growth and dark green color. P (phosphorus) promotes root development and flowering. K (potassium) is for overall hardiness and disease resistance. There are also secondary nutrients and trace nutrients.

Some orchid growers use high-nitrogen fertilizers such as 30-10-10 to grow more leaves and then change over to a balanced one. Of course, it’s easier to simply use the balanced formula, but the high-nitrogen  method works is if you remember to change over well before spring bloom period. 

Note: Remember that chemical fertilizers contain salts that can build up over time, possibly burning the tips of leaves. Rinse out these salts by occasionally watering with plain water.

The amount to feed your orchid depends upon the type you are growing. For most, the idea is to feed the orchid regularly but with a weak solution so that it doesn't shock the plant. Due to their varied habitats of origins, different orchids are conditioned to require various amounts of feeding. You can find information on feeding many of the most popular orchids to grow in the home in New York Botanical Garden's Orchid Culture Guides.

For tips on a variety of gardening topics, see our Plant Information Guides.

- Courtesy of NYBG Plant Information Service