Orchid fertilizers act as orchid nutrients which provide the essential elements required for orchid growth. Nitrogen, phosphorus and potassium are required in larger quantities and are termed as macro nutrients. Other elements
needed in smaller quantities are known as trace elements.
Commercial fertilizers consist of three main ingredients: nitrogen to promote general plant growth, phosphorus to promote flowering and potassium to promote strong roots. These ingredients are mixed in different combinations depending upon the plant needs. The combinations are indicated by a three number code, such as 10-20-30, where the numbers indicate the percent of nitrogen (N), phosphorus (P) and potassium (K) in the fertilizer, respectively.
Fertilizer Type
Most of the orchids are not heavy feeders and require lesser amounts of fertilizers. Fertilizing with a weak solution once a week is sufficient when growing orchids. A balanced fertilizer like 7-9-5 is good for all media used for growing orchids. A special type of fertilizer called as ‘blossom boosters’ can be used to promote flowering. The 3-12-6 formula is used just prior to bud formation. Fertilizers are distributed as granules, liquid, spikes etc. Water soluble orchid fertilizers are the recommended types to be used for growing orchids. Slow release fertilizers release nutrients over an extended period and thus stand the danger of being washed off with water. These should be used in greater quantities.
Fertilizer Dose
Orchids require lesser quantities of fertilizers as supplements and therefore the levels should be kept weak. The dosage varies with the manufacturers but the general recommended dosage is ¼ or ½ teaspoon per gallon of water. It is advised to keep the quantity low.
Frequency of Fertilization
Fertilizing every week is recommended but doing it every other week would be better. Watering every week and adding fertilizers to the water every other week is the recommended mode of rearing. Smaller growth and yellowing of leaves indicate insufficient fertilizing and should be supplemented accordingly.
Over Fertilizing
Development of white crusts on the media and around the pot indicates over fertilizing. The orchid roots turn black when they come in contact with the salt buildup and may die if it continues. The dying leaf tips also indicate the same. Alternate watering and fertilizing should be practiced to overcome the problem so that the residual fertilizers are washed off while doing so. Frequent clean water rinses can help solve the problem to a great extent. If the problem persists, repotting can be exercised.
Orchid Fertilizing Tips
1. Orchids should be watered weekly with lukewarm water.
2. Fertilizer should be added to the water every alternate week.
3. Avoid over fertilizing and check for drying and blackening of plant tips. They indicate over fertilizing.
4. Employ frequent clean water rinses between feedings to remove excess fertilizer from the media.
5. Follow ‘weakly, weekly’ principle for fertilizing. Avoid addition in excess amounts and during rest periods of the plants.
