how to fertilize orchids

How to Fertilize Orchids: Expert Tips for Healthy Blooms

Discover the secrets of how to fertilize orchids in this comprehensive guide designed to help you master the art of orchid fertilization, ensuring vibrant blooms and thriving plants.

Orchids are renowned for their exquisite beauty and grace, but nurturing them requires a nuanced approach to fertilization, including the right nutrients, perfect fertilizer ratios, and impeccable water quality. In this guide, we’ll delve into various types of fertilizers, uncover the ideal fertilizer ratios, and reveal the significance of water quality in preparing your fertilizer mixture.

By mastering these essentials, you’ll unlock the full potential of your orchids, leading to stunning, long-lasting blooms that will captivate and inspire. Let’s embark on the journey of learning how to fertilize orchids and transform your plants into mesmerizing works of art.

Understanding Orchid Fertilization

Orchid Nutrients

Orchids require specific nutrients to thrive and grow healthy. The key nutrients include Nitrogen (N), Phosphorus (P), and Potassium (K). These elements are crucial to orchid health and can be found in various fertilizers formulated specifically for these plants. An ideal fertilizer for orchids would be one with an equal 20-20-20 NPK blend.

Besides the primary nutrients, orchids also benefit from trace elements such as calcium, magnesium, and micronutrients. It’s essential to select a orchid food that includes these additional elements, promoting overall plant health.

Orchid Health and Growth

The health and growth of orchids are deeply connected to their fertilization practices, making it crucial to understand how to fertilize orchids effectively. When feeding orchids, there’s a mantra often repeated: “weekly, weakly.” This means that orchids should be fed with a diluted solution, around 1/2 to 1/4 strength, three out of four weeks a month. This practice helps maintain proper nutrient levels, ensuring a robust and healthy growth for the orchid.

A proper schedule not only keeps orchids healthy but also encourages growth and blooming. To promote growth, begin feeding after the last bloom dies and falls off the spike, during the orchid’s rest period.

It’s also important to provide orchids with adequate light, temperature, and humidity. This combination ensures optimal growth and blooming throughout the orchid’s lifecycle.

Primary NutrientsNitrogen, Phosphorus, Potassium
Fertilization ScheduleWeekly, weakly
Recommended Fertilizer20-20-20 NPK blend or similar
Water QualityLow salt content, appropriate pH level
TemperatureSpecies-specific, generally warm
LightBright, indirect light
HumidityModerate to high, species-specific


Orchids require specific nutrients, including Nitrogen, Phosphorus, and Potassium, plus trace elements for optimal health. Fertilize with a 20-20-20 NPK blend “weekly, weakly” at a diluted solution. Proper fertilization, light, temperature, and humidity promote growth and blooming throughout the orchid’s lifecycle.

Choosing the Right Orchid Fertilizer

woman feeding orchids with Water-Soluble Fertilizer

Orchids require specific nutrients to grow and thrive, including nitrogen, potassium, and phosphorus. Various types of fertilizers can cater to these needs, and orchid growers often use a combination of three main types: water-soluble, slow-release, and organic. Understanding your orchid’s needs and selecting the appropriate NPK ratio is crucial.

Water-Soluble Fertilizers

These fertilizers are mixed with water and applied directly to the orchid’s growing media or foliage, allowing for immediate uptake of nutrients. Common water-soluble fertilizers include:

  • Balanced fertilizers (e.g., 20-20-20): Equal amounts of nitrogen, phosphorus, and potassium. This combination promotes overall health, wellbeing, and steady growth.
  • High-nitrogen fertilizers (e.g., 30-10-10): Higher levels of nitrogen, beneficial for promoting foliage growth.
  • High-phosphorus fertilizers (e.g., 3-12-6): Higher levels of phosphorus, encouraging flower production.

Slow-Release Fertilizers

Coated granules that release nutrients over an extended period, providing a continuous supply of nutrients to orchids without the need for frequent applications. They work well when combined with a water-soluble fertilizer regimen to supplement nutrient delivery.

Organic Fertilizers

Organic fertilizers are derived from natural sources and can provide essential nutrients to orchids. They can also help improve soil quality and promote a healthy microbial environment in the growing medium. Common ingredients used in organic food for orchids include:

  • Nitrogen: grass clippings, milk, tea, coffee grounds
  • Phosphorus: bone meal, potatoes, coffee grounds
  • Potassium: milk, molasses, potatoes, ground chicken bones, coffee grounds


Orchids need specific nutrients like nitrogen, potassium, and phosphorus. Choose from three main fertilizer types: water-soluble (immediate nutrient uptake), slow-release (extended nutrient supply), and organic (natural sources). Select the appropriate NPK ratio for your orchid’s needs and consider combining types for optimal growth.

Orchid Fertilizer Schedule

how to fertilize orchids

Active Growth Cycle

During the active growth cycle, orchids generally need a balanced fertilizer containing nitrogen, phosphorus, and potassium, as well as essential trace elements. with a diluted solution of fertilizer at about 1/2 to 1/4 strength. This can be achieved using a 20-20-20 balanced fertilizer, ensuring that it contains little or no urea.

Here is a recommended feeding schedule for the active growth cycle, assuming one watering per week:

  • Week 1: Apply 3/4 teaspoon MSU fertilizer (a popular choice among orchid growers) per gallon of water
  • Week 2: Apply 3/4 teaspoon MSU fertilizer per gallon of water
  • Week 3: Apply 3/4 teaspoon MSU fertilizer per gallon of water
  • Week 4: Water only – no fertilizer

Dormant Cycle

The dormant cycle greatly depends on the specific orchid species, their natural environment, and the wet or dry season. In general, you can reduce the frequency of fertilizing during the dormant cycle compared to the active growth cycle. Keep in mind that some orchid species may enter a period of dormancy during the dry season, while others will typically not experience a dormant cycle.

Here are some suggestions for the dormant cycle:

  • Wet Season-Dry Season Cycle Orchids: Reduce frequency to once every two to four weeks, and consider using a lower strength solution (1/4 to 1/8 strength).
  • Other Orchid Species: Monitor the plant’s responses and adjust the fertilizing schedule accordingly. Keep an eye out for signs of nutrient deficiency or over-fertilization, and adjust the strength as needed.

During the dormancy period, orchids require different care routines. Reduce watering and stop fertilizing your orchids during this time. Over-fertilizing can stress the plant and delay dormancy, disrupting the natural growth cycle. Monitor your orchid closely and look for signs of new growth before resuming fertilization.


During an orchid’s active growth cycle, fertilize “weekly, weakly” with a diluted 20-20-20 fertilizer, ensuring little or no urea. In the dormant cycle, reduce fertilizer frequency and strength depending on the species. Monitor for nutrient deficiency or over-fertilization, and adjust care routines accordingly.

Preparing the Fertilizer Mixture

To prepare the mixture and fertilize orchids, use a clean watering can and ensure it is rinsed thoroughly before mixing. The quality of water is crucial for nutrient absorption, so opt for distilled water or rainwater whenever possible. If tap water is the only option, let it sit in an open container for at least 24 hours to reduce dissolved minerals and impurities.

  • Distilled Water: Best option, free from dissolved minerals or impurities.
  • Rainwater: Generally free from dissolved minerals; collect in a clean container and test pH level and dissolved minerals if possible.
  • Tap Water: Alternative option, but may contain dissolved minerals and chemicals; allow it to sit for 24 hours before use.

Always use room temperature water for best results and follow the package instructions for dilution rates.

Common Orchid Fertilization Concerns

woman giving fertilizer to a orchid plant


Orchids are sensitive to salts, which are generally found in fertilizers. Overfeeding can lead to salt build-up in the growing medium, causing root damage and negatively affecting the plant’s overall health. To prevent this issue, provide a diluted solution once a week.

Plant Diseases

Orchid diseases can be a significant concern, and improper fertilization can increase the risk of these issues. Over-fertilizing orchids can weaken the plant, making it more susceptible to infections and pests.

  • Orchid Health: Regular fertilization is crucial for healthy orchid growth, but overdoing it can lead to problems such as salt build-up and increased susceptibility to diseases.
  • Orchid Growth: Keep an eye out for symptoms of over-fertilization, such as weak stems, yellowing leaves, or droopy foliage, and adjust the fertilization routine as needed.
  • Orchid Care: Carefully follow a schedule that involves weekly applications of diluted fertilizer during the growing season, while avoiding during dormancy.
  • Dormancy: Respect your orchid’s dormancy period, reducing watering and withholding fertilizer until new growth is observed.


Avoid overfeeding orchids, as it can cause salt build-up and increase disease susceptibility. Follow the “weekly, weakly” rule with diluted fertilizer. Monitor for over-fertilization symptoms and adjust routines as needed. Respect dormancy periods, reducing watering and withholding fertilizer.

Adapting Fertilization to Specific Orchid Genera


Dendrobiums are a diverse genus of orchids, comprising over 1,200 species. They have specific feeding needs to thrive and bloom. To adequately feed Dendrobium orchids, it is recommended to use a balanced fertilizer with equal nitrogen, phosphorus, and potassium components, such as a 20-20-20 blend. When using this blend, prepare it at 1/4 strength for effective application.

Here are a few key points to consider when fertilizing Dendrobiums:

  • Frequency: every 3 to 4 weeks during the active growing season.
  • Dilution: Use rainwater for dilution instead of tap water, as tap water may contain chlorine harmful to orchid roots.
  • Application: Apply evenly and thoroughly to both the orchid’s roots and foliage.


Cattleya orchids are popular among orchid enthusiasts for their stunning blooms and ease of care. Fertilizing Cattleya orchids requires an understanding of the specific plant’s feeding needs, which can vary depending on the particular species within the genus.

A higher phosphorous solution, such as a 3-12-6 blend, is recommended to promote flowering in Cattleya orchids. When using this blend, make sure to follow the label directions precisely.

Here are some important factors to consider:

  • Frequency: every 2 to 3 weeks during the active growing season, and reduce to once a month during the winter months.
  • Dilution: As with Dendrobiums, use rainwater to dilute instead of tap water.
  • Application: Apply the fertilizer to the roots, as well as the foliage and aerial roots if present.

Monitoring and adapting your routine to meet the needs of the specific orchid genera in your collection will help ensure overall plant health and an increased likelihood of stunning blooms.


For Dendrobium orchids, use a 20-20-20 fertilizer blend at 1/4 strength every 3-4 weeks during the active growth season, and apply evenly to roots and foliage with rainwater. For Cattleya orchids, use a 3-12-6 blend, fertilizing every 2-3 weeks in the growing season and monthly in winter. Adjust fertilization routines for specific genera to ensure overall health and blooms.

Before you go…

Proper fertilization is key to the health, growth, and blooming of orchids. By choosing the right type of fertilizer, understanding the appropriate NPK ratio, and adjusting the schedule according to the orchid’s growth cycle, you can help your orchids thrive. Remember to provide adequate light, temperature, and humidity to complement your fertilization routine. Check out our other posts on orchid care for more tips and tricks to keep your orchids healthy and beautiful!

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