Orchids, flowers famed for their beauty and diversity in colors and shapes and sizes. Orchids belong to the largest family of flowering plants in the world which boasts over 28000 known species. They are also notoriously difficult to grow and are quite complex in terms of how they need to be nurtured in order to thrive.
In the wild, orchids have access to the proper conditions and nutrients that they receive from bark, rotting leaves, fungi, lichen, rainwater and even from bird droppings. However, creating the same conditions in your home is a completely different story.
Taking good care of your orchid, whether in a garden or inside your home, does not stop at watering- you have to feed them too. Their food consists of fertilizers, which needs to be fed to the orchids in a proper manner with the correct types of fertilizers.
Navigating the world of fertilizers can be tricky as there is a lot of science behind it and there are also so many fertilizers on the market. What’s more is that choosing the wrong fertilizers could cause damage to your plant.
This guide has been put together taking into consideration the best fertilizers out there and also gives you more information about how and when to fertilize them to ensure that you maintain a healthy plant for a long time to come.
What is a Fertilizer?
First thing is first, fertilizer is a chemical or natural substance that is added to the soil to optimize soil health so that the plant can take up all the nutrients it requires to grow and thrive. Fertilizers are generally made up of three elemental nutrients essential for plant growth.
These nutrients are nitrogen (N), phosphorous (P) and potassium (K) and are combined in specific ratios depending on the needs of the plants.
Different Types of Fertilizer
There are two main types of fertilizers that can be used for orchids. These are your slow-release (or spike fertilizers) and your foliar fertilizer. A slow-release fertilizer only needs to be applied or fed to the orchid once every two to nine months, depending on the product.
The nutrients will seep into the soil and the root system gradually on a daily basis. The slow release fertilizer type is beneficial if you lead a busy lifestyle but are still passionate about orchids and their care. Whereas, foliar fertilizers need to be applied or fed to the plants on a regular basis- usually once a week or so.
This option of fertilizer is optimal if you have more hand-on time to take care of your plants.
The fertilizer types also come in different formats. The most popular types of fertilizer formats are concentrated liquid fertilizer or water-soluble granules that can be added to water and dissolved to form a solution. Adding of the foods to water is valuable and a time saver, as this means you can water and feed your plants at the same time.
What Nutrients Do Orchids Need?
For orchids to produce their beautiful flowers and luscious green foliage, they require 13 nutrients in total, three of which are nitrogen, phosphorous and potassium or NPK. Nitrogen is important for the rapid growth of plants and is an essential element to nourish the leaves and to ensure that the leaves maintain a good health and color.
Phosphorous encourages the growth of healthy and robust roots and ensures optimal bud and fruit development over time. Lastly, potassium is an essential substance for bulbs and tubers and used as a defense against the environmental changes that are bound to occur in a plant’s life, such as pests and climate changes.
Potassium is also critical in preventing yellow leaves and underdeveloped or stunted plants. Other elemental minerals such as calcium, magnesium and sulfur are also significant in maintaining good plant health, but in fertilizer mixes, they are used in smaller quantities.
However, they assist with the rooting process, flower germination and production of defense substances, as well as assistance with essential processes like cell division and respiration.
It is important to note that for orchids, fertilizers containing urea sources are not optimal to use. This is because the soil microorganisms must first transform the Nitrogen available in the urea into a substrate that is more available for uptake for a plant and this makes for an inefficient and ineffective process as orchids, generally, are not housed or rooted in the soil.
On the other hand, a good orchid fertilizer contains a 20-20-20 ratio of nitrogen, phosphorus and potassium. This ratio provides a good balance of nutrients for terrestrial orchids. However, if you are growing your orchids in a medium that isn’t soil, you should opt for a higher nitrogen concentration in the fertilizer mix. This is because these epiphytic orchids are grown in a non-soil based medium like bark, which naturally has a lower nitrogen content than soil does.
Another thing to consider when buying a fertilizer is the stage of development your orchid is in because it is going to need a different cocktail of nutrients depending on where it is at in its life cycle.
Stages of Development
Orchids go through three stages of development. These stages begin with the development of stems, followed by the formation of buds and then flowering.
First Stage- Leaf Stem Development
This stage occurs when the sprout is at its most developed and continues until there are signs of a bud starting to form at the tip of its leaves. During this stage, the orchid requires lots of Nitrogen to nourish the leaves and for rapid growth. As a result, slow-release fertilizer with a high Nitrogen content, such as 30-10-10, is highly advisable.
Second Stage- Bud Formation
This next stage is when orchids store nutrients and prepare to flower. They therefore require all three elemental minerals, with special emphasis on phosphorous in some cases. Ideally, at this stage, the fertilizer ratio of NPK for your orchids in this period is a balanced one, such as 20-20-20 or 14-14-14.
Third Stage- Flowering
Potassium is used a lot in this stage, and so it should be prioritized when choosing a fertilizer.
Frequency of Feeding
This depends on the type of fertilizer used, but expert growers usually select a foliar fertilizer to use and feed the orchids on a weekly basis with a weaker solution of fertilizer. It has been demonstrated that doing this, feeding more often with diluted fertilizer will result in more optimal orchid growth and health over time than when fertilizing at a higher concentration, less often.
Orchids need to be fed during their stages of growth like mentioned above, and it is important to remember that orchids go dormant in the winter and so should only be fed in the spring again. It is also crucial to remember to not feed sick plants when they are weak as this puts more strain on them, and they should conversely not be overfed.
You know they have been overfed when their leaves are very dark and floppy. Overfeeding them will force them to grow too fast, making them more susceptible to disease over time.
How to Spot Nutrient Deficiencies
If a plant lacks nitrogen, the plant will be stunted and the quantity of buds and leaves on the plant is limited. A lack of phosphate means that the plants are short and small and will have underdeveloped roots and young shoots are unable to grow, and the plants will flower slowly.
Likewise, a potassium deficiency is indicated by underdeveloped and dwarfed plants that will be susceptible to disease and pests. Other deficiencies like calcium, magnesium and sulfur are characterized by weak plants, large roots and barren plants with yellow leaves, respectively.
Deficiencies in zinc, iron, copper and manganese are characterized by pointy leaves, yellow and white leaves, and young leaves will appear to have yellow streaks on them, respectively.
Best Orchid Fertilizers on the Market
The fertilizers in this list have been evaluated on the quality of fertilizer in terms of the nutrient balance, the end results and their ease of use. Customer reviews and satisfaction have also been taken into consideration.
Nutrient ratio: 0.2 – 0.2 – 0.2 N-P-K
This fertilizer comes ready-to-spray, which means that it does not need to be diluted, and the spray bottle makes applying the fertilizer solution directly to the roots, the growth medium and the leaves of your orchid an absolute breeze. It is a great way to hydrate and nourish your plants all in one application.
Although many orchid fertilizers advise against spraying on the leaves, this fertilizer does not burn or do any other harm to the leaves and the positive results were quick to notice. However, if your plant is going through the flowering stage, then do not spray this solution onto any flowers as it will harm them. It is best to follow the manufacturer’s instructions to the letter on this one.
With the Miracle-Gro 100195 Ready-To-Use Orchid Plant Food Mist, you should spray your orchids weekly throughout their growth stage and water between feeds.
When testing this product, we loved that it doesn’t need to be diluted, that it instantly moisturizes and nourishes plants and that it is really effective on terrestrial orchids and results are evident within a few weeks.
Nutrient ratio: 11 – 35 – 15 N-P-K
The Better Gro 8305 Orchid Better-Bloom Booster is a great fertilizer to use when your orchid hasn’t bloomed for a while or need to be encouraged to start growing. Due to its significantly higher phosphorus content, the fertilizer encourages the development of new buds and enhances the longevity and the quality of the flowers that bloom from the orchid plant. The results are fast and include strong, healthy growth and bigger blooms.
It is recommended that this fertilizer be used throughout the growing season of epiphytic orchids, specifically to replace the nutrients that are lost through having a non-soil-based growth medium or environment. However, if your orchid is in its infancy, it may be best to use other food.
As this is a granular product, the granules need to be dissolved in water and then applied to the orchid on a monthly basis throughout the growing season. The granules are easy to dilute and make application of the fertilizer easy. Again, it is best to stick to the manufacturer’s recommended instructions on application to ensure no damage is incurred on the plant or the blooms.
When testing this product, we loved that the results are bigger blooms after a short period of use. We also loved the intensity of color in the blooms as a result of the application of this fertilizer.
Nutrient ratio: 1.19 – 1.06 – 0.39 N-P-K
Living up to its slogan, this orchid fertilizer is renowned for improving your blooms and helps your mature plants to rebloom with its effective NPK formula.
The formulation gives your orchids the boost they need and will result in a high yield of flowers and will enrich your plants to promote growth, strong root development and will give your leaves a deep rich color. It contains all natural and organic ingredients like liquid kelp, fish and a mix of plant and rooting hormones all packed together in a deodorized formula.
The product comes in a 16 and 32 oz containers and needs to be shaken before diluting in water in the correct ratios. The manufacturer recommends adding 1 -2 oz. of plant food concentrate to a gallon of water or, for smaller amounts, a tablespoon of plant food with a quart of water.
This plant food can be used to water your plants on a weekly basis, alternating with plain water every third week or so.
When testing this product, we loved that the solution is easy to mix and that it is very effective to use on mature plants for reblooming purposes
Nutrient ratio: 10 – 10 – 17 N-P-K
High in potassium, the Florikan Dynamite Fertilizer will encourage your orchids to yield more flowers throughout the year, on top of it being a slow-release fertilizer made out of granules. It is a perfect solution for the type of gardener that forgets about feeding or who simply does not have enough time as with this fertilizer, you will not have to worry about feeding your plants on a regular basis. This is because you only have to feed your orchids once every nine months… yes, you read right.
To use the product, you will need to know and measure the size of your orchid’s pot before being able to determine the dosage of the amount of granules needed. All that is left to be done after that is to sprinkle the slow-release granules around the potting medium and then to water on a regular basis as per usual.
When testing this product, we loved that feeding your orchids could not be easier for those forgetful gardeners! The size and beauty of the blooms that followed were also incredible.
Nutrient ratio: 20 – 10 – 20 N-P-K
High in potassium and nitrogen, the Grow More Urea Free Orchid Fertilizer will get to work straight away and encourage the rapid growth and development of foliage and blooms in your orchids. The blooms that are grown are vibrant and big. The biggest advantage of this product is that it is free from urea.
Urea is usually a good source of nitrogen for most plants grown in soil, where the microorganisms can convert nitrogen into nitrates and nitrites, which plans can take up easily. Urea it is really inefficient to use for epiphytic orchids as these do not have the microbes which are able to facilitate the conversion and therefore does not get taken up or absorbed by the epiphytic plants.
The granules of this product are water-soluble and dissolve really quickly and easily in water. The orchids can then be fertilized weekly with a solution of 1 teaspoon of granules for a gallon of water. For epiphytic orchids, it is a good idea to soak the growth medium with the solution and let it drain before placing the orchid pack into the pot.
This is handy as you can water and feed simultaneously and do not have to worry about watering in between feeds. Although, you may want to use one week of the month for just a plain or regular water. Be careful to follow the manufacturer’s instructions, as if you over use it, it may have harsh and damaging effects on the plant.
When testing this product, we loved that it gets to work straight away and that it is free from urea.
Nutrient ratio: 10 – 10 – 10 N-P-K
Miracle-Gro has created these plant food spikes to take the challenge out of fertilizing your plants. With their balanced NPK ratio, the slow release formula present in these food spikes are suitable for any orchid. The spikes themselves only need to replaced every two months throughout the growing season and do not need to be used otherwise.
They have color of the red spikes to make it easy to see when they are in need of replacing, and they are really easy to use. You simply break a spike in half and place the two halves into the pot, equidistant from each other and between the plant and the pot’s edge. All you have to do then is water regularly to disperse the nutrients directly into the soil near the root.
When testing this product, we loved that there is no dilution or maintenance required with this fertilizer and it is good value for money.
Nutrient ratio: 1.3 – 1.2 – 1.1 N-P-K
Another plant food spike that is available on the market are the EarthPods B079344QTQ Orchid Organic Plant Food Spikes. These organic plant food spike capsules are urea free and contain all the phytonutrients, minerals, natural growth hormones, amino acids and beneficial microorganisms required for good plant health.
What is more is that the formulation will boost root growth and increase the amount of blooms and foliage, naturally. They are also pet, child and eco-friendly and can be used on all types of plants, not just orchids.
These spikes should be replaced every two to three weeks, with water in between, to maintain optimal plant health. For small plants you should use 1-2 capsules, medium 2-4 capsules and for larger sized plants use 4-8 capsules per use.
Once nourished, your plants capability to absorb sunlight will increase and the chlorophyll content, and the result is extremely green leaves. The slow-release action also means that the growth will be gradual, but new buds will sprout quickly once the plants have matured. The only drawback of this product is that it is not the most economical option out there.
When testing this product, we loved that it is so easy to use and how environmentally friendly the product is.
Nutrient ratio: 1 – 3 – 1 N-P-K
Epsoma, a trusted brand in the plant food world, has developed an organic liquid fertilizer which is the right balance of ingredients and nutrients within a reasonable price range. The formula of this solution has a very high phosphorus content, which means that the orchids will grow to be robust plants and will have a longer longevity.
Their resultant blooms will also maintain a vibrant color and will last longer too. This plant food is made with hydrolyzed soy protein, fish protein, poultry waste, bone meal, kelp and potassium sulfate along with a lot of good microorganisms to maintain plant health.
What is great about this fertilizer is that you don’t have to mix anything to get the correct dose as the product contains pre-measured product doses or 0.2 fl oz. Every two to four weeks, one dose should be added to a quart of water to feed your plants, which is then easy to apply to the plants.
It is important to note that because of its ingredients, the organic material and microorganisms build up inside the container, so it is best to shake the product before use and open the container very slowly to release the gas.
When testing this product, we loved that it uses high quality, organic ingredients.
Nutrient ratio: 14 – 14 – 14 N-P-K
Having the best NPK ratio out of all the products reviewed here, the Osmocote 274150 Smart-Release Plant Food Plus Outdoor & Indoor can fertilize all kinds of plants- those that grow in soil outdoors and potted plants inside your home. It has 11 essential nutrients and each granule is coated with a unique resin that controls the release of nutrients so that plants get the nutrients they need when they need it.
The fertilizer is a slow-release fertilizer which for outdoor use should be sprinkled across areas to be fed and worked into the top 1-3 inches of soil. When applied to indoor plants, you can mix the granules into the soil or growth medium at the bottom of the roots of the plant.
The granules should be sprinkled over the soil every 4 months; this applies to both indoor and outdoor plants. As an added benefit, if you go over the top with the amount of granules you sprinkle on top of the soil, the plant will not experience any burn- as long as you use the fertilizer according to the manufacturer’s instructions.
When testing this product, we loved its ability to be applied directly to the plants and that it can be used in outdoor and indoor plants.
Nutrient ratio: 20 – 14 – 13 N-P-K
Developed by their in-house experts, this fertilizer from Better Gro is packed with nitrates, is urea free. It is fast acting and promotes rapid growth of your orchids. It also contains all the essential nutrients you would expect from a fertilizer to ensure healthy plant growth and maintenance.
The fertilizer lasts for a long time, as you only require a teaspoon of formula per gallon of water. You can choose to fertilize your orchid once a month, or you can use the feed weekly, weakly method. It is an ideal mixture for young orchids and is simple to work with, and you really get bang for your buck with this formulation.
When testing this product, we loved that it makes for rapid growth of your orchids.
Nutrient ratio: 3 – 1 – 2 N-P-K
Although not specifically designed for orchids, this ready-to-use fertilizer from Houseplant Resource Center is gentle enough to be used to feed your plant with every water, providing your orchid with the nutrients they need to thrive day in, day out, all year around. What is great about this product is that you don’t need to buy any other plant food for your other houseplants- it is a one-size-fits-all fertilizer solution and so is quite cost-effective overall.
All the ingredients are natural and organic and additionally contains slow-release calcium for steady growth of your plants all year round. Add a teaspoon of this fertilizer mix to water that you use to water your orchids every time you water to give your orchid a steady supply of nutrients without it harming the plant.
When testing this product, we loved that it is gentle to use on every water.
The best orchid fertilizer should work for you and your gardening habits or capabilities. If you are pressed for time, use one of the ready-to-use fertilizers. If you are a houseplant-hoarder, then a multipurpose fertilizer would be better.
Hopefully, after reading this guide, you will feel better equipped to make the right decision on which fertilizer to use for your orchids to have happy and healthy blooms all year round!