Houseplant Hero to the rescue! Use Orchid Plant Food on all ochids. May be used every time you water or once or twice per month. Concentrated formula. If applying once or twice per month, use 1/4 teaspoon per quart of water. If applying every time you water, use 1/8 teaspoon per quart of water. 9 - 7 - 9 (9 nitrogen - 7 phosphorus - 9 potassium). 8 oz. bottle.