Paphiopedilum sukhakuliid orchid in full bloom.
image by Dalton Holland Baptista:commons.wikimedia.org
Though commonly thought to be light feeders, orchid plants make good use of the nutrients supplied by fertilizers but they do require a light hand in application. Commercial orchid food formulations are widely available and remain the easiest way to feed your orchids the complete nutrition they require. Diluted with water and applied once a month, orchid food can boost bloom, green foliage growth and produce more vigorous root systems.
Select a brand of water soluble orchid food in crystal or liquid form. Most brands that are labeled for orchids will be fine. What they have in addition to the nitrogen, phosphorous and potassium in most fertilizers are trace elements and minerals that make up for the deficiencies that the preferred orchid potting medium of bark cannot provide. Use a high nitrogen water soluble fertilizer like MiracleGro if you do not have access to orchid food. Mix the fertilizer with water at a diluted strength, and use regularly to feed your orchids.
Determine a feeding regimen for your orchid that you can stick to, choosing either the weekly or monthly feeding method. Weekly feeding is done once every 5 to 7 days after watering with a very weak fertilizer and water solution washed through the roots and planting medium. Monthly feeding is done after watering every fourth week with a slightly stronger fertilizer solution applied in the same method. Sticking with a schedule prevents over or under fertilizing which can both disrupt performance and bloom.
Mix the fertilizer solution with cool to tepid water in a pitcher or container from which you can easily pour. Consult fertilizer label directions for use. For weekly weak feeding use 1/4 of the recommended dose of fertilizer to the full amount of water. For monthly feeding mix 3/4 up to the full recommended dose of fertilizer with water. As with many things in life, more is not better and so it is when feeding your orchid. Always err on the side of less fertilizer applied weakly to prevent burn to the roots and over buildup of mineral salts in the planting medium.
Hold your orchid pot over the sink, and water it well with clean water from the faucet. Let the excess water drain out for a minute or so. Pour the fertilizer and water solution slowly and evenly over the roots and planting medium all around the pot but avoiding the leaves. Allow the excess solution to drain away, and put your orchid back in its usual living space until the next watering.