David's (Orchid Nerd) Orchid Tips: The Importance of Proper Fertilizing

Making sense of the Numbers
by Melanie Dearringer of Orchid Plant Care

Fertilizer plays an important role in maintaining your orchid. But before you run to the store to make a purchase and find yourself overwhelmed with the abundance of different options available, let’s dig a little deeper into the fundamentals of fertilizer. Each fertilizer product advertises three numbers on the front of its package. These numbers actually provide great understanding as to what the fertilizer will do.

The numbers refer to the percentage by weight of Nitrogen, Phosphorus, and Potassium (NPK – always listed in that order) within that particular fertilizer compound. A balanced fertilizer, such as a 20-20-20, is made up of equal parts of Nitrogen, Phosphorus, and Potassium each representing 20%.  Anyone who is doing their math will undoubtedly realize that these numbers do not add up to 100%. This is because while fertilizers contain more than three nutrients, NPK are the only prominently displayed elements due to your plant’s need for them in a higher quantity.

Now that you know what the numbers represent, how can you use this information to choose the right formula? First, it is important to know how these different nutrients affect your orchid. Nitrogen promotes growth in the parts of your plant that you can see above your potting mix, such as foliage. Phosphorus is responsible for the part of your orchid beneath the potting mix. It encourages healthy root systems and is responsible for beautiful flower blooms. And finally, Potassium is crucial for your orchid’s overall health. This important nutrient helps plants deal with the stresses associated with temperature, disease, and insects.

The Importance of Proper Fertilizing

It is always very important to feed your plants, not only while they are growing, but also when they are in bloom. Like all living things, when fed properly, they will grow stronger and produce more flowers. Our product of choice is Dyna-Gro, but any balanced fertilizer may be used. Brands such as Dyna-Gro and Peters are also known for quality fertilizers and supplements. We recommend watering the plant prior to applying fertilizer and then following one of the two sets of instructions on the manufacturer’s label. One is for feeding (1/4-1/2 tsp/gallon) weekly and one is for intermittent feeding (1-3 tsp/gallon) every 2 to 4 weeks. If you cannot fertilize as often as you should, then use a timed release fertilizer to supplement regular feedings. Depending on the brand and formula, granules will last from 3-12 months. Top dress your plant with the manufacturer’s recommended amount. Sprinkle the feed evenly across the surface of the mix taking care not to get it close to the new growths. Do not use this type of fertilizer with sphagnum moss. Because the moss is constantly moist, it will continuously release nutrients and could burn the roots of your plants.