It is always an exciting time as the warmer weather returns and orchids begin showing signs of growth—those wonderful, bright green shoots that magically appear, sometimes overnight! To keep orchids growing and blooming throughout the seasons, it is important to ensure their overall health from the potting media and roots to the tips of their leaves. All orchids need light, water and nutrients. Nutrients in the form of fertilizers and supplements ensure your plants have the nutrition needed to promote optimal health, growth and vigorous blooming.

Organic vs. Inorganic
Nutrients may be provided in organic or inorganic forms. Organic products are derived solely from carbon sources or sources “of the earth,” i.e., derived from plants, animals or naturally occurring compounds. Organic products are typically less processed and frequently do not have as high of a Nitrogen-Phosphorus-Potassium (N-P-K) value as inorganic products. Inorganic indicates the chemical fertilizers or supplements are not directly derived from plant or animal sources. To make inorganic products, organic matter is typically broken down into its individual elements, such as nitrogen, iron, magnesium, and potassium. These individual elements are then combined in new ways to create specific blends of fertilizers or plant nutrition supplements, resulting in the various fertilizers on the market bearing N-P-K values of 7-9-5, 15-30-15, 13-13-13, etc.

It is a good idea to consider the pros and cons of using organic versus inorganic nutrient sources for your plants. There are benefits to utilizing the least processed plant nutrient sources. Just as your body will receive more benefit from a whole orange (vitamin C plus fiber, potassium and a variety of other nutrients) than a vitamin C pill will provide, plants may receive many benefits (increased chlorophyll production, greater beneficial soil microbe activity, etc.) from organic seaweed than from an inorganic fertilizer with the same N-P-K of 0.1-0.0-1.0. Determining the nutrients various plants or orchids need in varying growing environments and the way plants use those nutrients is a complex science.  The main problem with using inorganic fertilization is excess run-off or waste into surrounding soils and water sources. Much of this waste can be alleviated by using hydroponic methods to capture the enriched water and re-circulate it. In growing our various orchids and plants, we have found that a combination of organic and inorganic products promotes ideal growth and blooming within our collection.

Organic Fertilizers
The use of organic fertilizers such as fish emulsion and seaweed has a very long history. These two products are often used together or alternated during fertilization cycles to maximize the benefit to plants. Other organic fertilizers that are sometimes utilized by orchid growers are bat guano, various animal manure (usually horse, llama or cow), and compost or worm tea.  

Maxicrop Seaweed 0.1-0.0-1.0 is a rich organic plant stimulant made from Norwegian seaweed. It feeds plants with a wide range of nutrients, growth bio-stimulants and conditioners. The seaweed stimulates beneficial soil microbe activity which helps to form a “biological barrier” between your plants and invasive bacteria, virus, or microorganisms. As plants grow in this protective environment, they have an improved resistance to stress.  By improving the soil conditions, seaweed results in extended root systems which allow plants to absorb more nutrients.

The organic matter supplied in Alaska Fish Fertilizer 5-1-1 is highly bio-active and provides micronutrients in addition to the macronutrients N-P-K. Fish emulsion promotes the stimulation of beneficial bacteria in the soil and also results in improved plant resistance to stresses such as heat, drought, and invasive pathogens. It works so well for plants in environmentally challenged areas that many landscapers in the Phoenix, AZ area recommend Liquid Fish as the sole fertilizer. The phosphates in Fish Emulsion promote root development while the nitrogen aids in plant growth. We typically use liquid fish on our orchids once or twice a month, alternating weeks with Maxicrop seaweed. Liquid Seaweed and Liquid Fish Emulsion are often used in combination to optimize plant and root growth while improving plant resistance to pests. The Ortho Dial ‘n Spray results in a perfect dilution rate and does not affect the integrity of the fertilizer.

For optimal results, you may start using fish emulsion early in the growing season while temperatures are still cool. Also useful as a foliar spray, the enhanced bioactivity on the plant leaves may help to prevent fungi such as mildew from establishing. Foliar spraying sometimes deters wildlife that would typically nibble your plants. This 5-1-1 formula is deodorized and may be used on all indoor and outdoor plants and will not burn the plants or roots. Alaska Fish Emulsion is OMRI (Organic Materials Review Institute) listed and is approved for use in the production of organic food.

Neem Seed Meal 4-1-1 is a slow-release organic fertilizer that is the by-product of pressing the Neem seed for its oil. It contains more nitrogen, phosphorus, potassium, calcium and magnesium than traditional manure or sewage sludge, providing an important variety of benefits to your plants and growing medium. Neem seed meal is effective for nematode and pest control, fungi and bacteria management, and improved soil fertility. Recommended use is 1-3 oz. of Neem seed meal for each 6” to 12” pot.
Inorganic Fertilizers

Most fertilizers on the market are inorganic, bearing a wide range of N-P-K values and quality of fertilizer components. Dyna-Gro’s Liquid Grow 7-9-5 and Liquid Bloom 3-12-6 are two of the most commonly used fertilizers for orchids. Depending on the types of orchids grown, you may need to offer Dyna-Gro Liquid Grow part of the year and then switch to Liquid Bloom during another season. We grow a lot of summer blooming orchids, so we use Liquid Grow throughout the majority of the year but switch to Liquid Bloom in the fall before the orchids go into their dormant period. This way the plants store the phosphorus and are more likely to bloom in the early summer.

Dyna-Gro Liquid Grow offers a complete nutrition formula, providing all six essential macronutrients and all ten essential micronutrients. It is an ideal all-purpose fertilizer, especially for hydroponics and orchids. If you have only a few orchids and do not want to purchase a lot of fertilizers, this will likely meet your orchids’ needs since it promotes both foliage growth and blooms. When you fertilize orchids, remember the phrase, “Fertilize weakly weekly.” One-quarter teaspoon of fertilizer per gallon of water, fertilizing once a week each week is usually ideal.

Dyna-Gro Liquid Bloom 3-12-6 is a low nitrogen, high phosphorus nutrition formula to promote the development of large vibrant blooms. It is excellent for orchids, African violets, roses and all other flowering plants. Liquid Bloom should also be applied at a rate of ¼ teaspoon per gallon of water. The best time to use Liquid Bloom is before the flower buds appear, or even before the spike appears, to help initiate flowering and avoid stem elongation which can decrease the stem’s strength.

Controlled Release Inorganic Fertilizers
Nutricote is a rather difficult product to find, but is a true luxury for growers of orchids, palms, ornamentals and perennials. Nutricote is a true controlled-release fertilizer that is ideal for every grower and gardener. Nutricote is known for its special resin coating of nitrate compound fertilizers. The gray resin coating controls the rate and duration of nutrient release with unequaled consistency and precision.

When Nutricote is applied to soil, the water in the soil enters the granule through micro-pores, dissolving the nutrient elements in the granule.  The nutrient elements are then released through the pores at a rate (40 to 360 days) determined by the type of resin coating present on the granule. The resin coating on Nutricote granules makes it very safe. It will not burn plants and there is no flash nutrient release. Nutricote contains N, P, and K with high nitrate nitrogen content. Nutricote Total blends contain all essential micronutrients for your plants.

As soil temperatures increase so does the nutrient release from Nutricote. At increased temperatures, absorption of nutrients and water by plants generally increases and plant growth will become more vigorous as a result. Nutrient supply from Nutricote corresponds with the physiology of plant response to temperature. The release rate of Nutricote is not significantly influenced by soil moisture levels, and it is unaffected by soil pH. Nutricote may be used as top-dressing and may be used in conjunction with liquid fertilizing. We usually top-dress most of our orchids with a Nutricote Total blend, using 1-2 teaspoons for each 4”-6” pot size.

Nutrient Supplements
Supplements augment the fertilization program that you use for your plants and orchids. Below is a chart showing some of the most popular and useful supplements along with recommended usage rates and purposes.
After watching your orchids grow and bloom year after year, it will hopefully become clearer when they are not receiving enough of certain nutrients or when they need a boost. It is always a good idea to discuss growing techniques with other growers in your local orchid society to learn about their various experiences. When considering the nutritional needs of plants, keep in mind that water quality, type (reverse osmosis, rainwater, or distilled), and pH all play a role in the availability and absorption of nutrients by your orchids. Wishing you a summer of many spikes and blooms! GG

Amanda Sylvie is the owner of Lone Star Orchids and may be contacted by calling 866.433.8256 or emailing This e-mail address is being protected from spam bots, you need JavaScript enabled to view it . You can visit her website at www.lonestarorchids.com .