How and When To Fertilize Orchids – Complete Guide

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How and When To Fertilize Orchids – Complete Guide: It’s not hard to take care of flowers, but there are a few important things that will make a big difference. Melissa Strauss, a gardening expert and orchid lover, writes this piece about how to fertilise orchids so they have lots of beautiful blooms.

A delicate purple vase sits beautifully on a sunny windowsill, filled with bright purple orchids that add a pop of colour against the white. In the background, more orchids are in several purple vases, making a beautiful and harmonious show of flowers.
What It Includes

Some people are very picky about how they care for and keep orchids. It depends on the type, but one thing is always the same: it’s hard. You can’t just put an orchid on a shelf and forget about it; it needs to be cared for.

It takes just the right amount of light, water, temperature changes, and, perhaps most importantly, fertiliser to get an orchid to grow. People say that orchids eat a lot. As they are usually put in bark that doesn’t hold much water, these plants don’t have potting soil to get nutrients from. This means that you have to work hard to give them the nutrients they need for them to do well.

Why fertiliser is important

With clear gloves on, hands carefully pour fertiliser from a green bottle into an orange lid. Nearby, a yellow bottle is ready to be used in this colourful outdoor scene. In the blurred background, potted plants look nice.


Fertiliser affects how fast plants grow, how flowers open, and how roots grow.
For plants to grow, flowers to form, and roots to form, fertiliser has different jobs to do. What things the fertiliser will help the most will depend on the ratio of nutrients in it. The macronutrients are what we usually mean when we talk about fertiliser ingredients. These are nitrogen, phosphorus, and potassium, which are written as N-P-K.

To find out what kind of fertiliser something is, look at the numbers that are written next to these three macronutrients. For instance, a fertiliser with a ratio of 10-10-10 has the same amount of all three macronutrients. Each of these nutrients helps plants grow in its own way.

Gas Nitrogen

As seen up close, a hand wearing a blue glove holds white nitrogen fertiliser pellets with great care. A soft blur in the background shows a bag with the same granules sitting on top of a thick bed of green grass.


Chlorophyll is made and leaves grow with the help of this important nutrient.
A big part of the process of respiration is nitrogen. A plant will not have chlorophyll if it doesn’t get nitrogen, which could show up as leaves turning yellow. It also helps the roots control how much water and nutrients they take in and gives the plant energy to keep growing.

The element phosphorus

A closer look at diammonium phosphorus fertiliser granules in a rough bag, showing a group of small, dark particles. The grains are neatly grouped and have a rich, earthy colour that shows how high in phosphorus they are. They are ready to be used in agriculture.

Plants need phosphorus for photosynthesis, energy storage, root growth, and flower formation.
Phosphorus is also important for photosynthesis because it helps the plant store and send energy to different parts of the plant.

More importantly, it is an important part of making flowers and is needed for most flowering plants to grow seeds. This is what makes most flower species flower and fruit. This substance helps break down sugars, divide cells, and make new cells. Additionally, phosphorus helps roots grow, which makes it an important part of fertilising flowering plants.

Sodium and potassium

A hand wearing a green glove holds a bunch of brown potassium fertiliser grains. It is next to a big pile of potassium grains, which make up a varied and large collection of this important farming supplement.

Soil and water can move through the plant better.

Potassium aids the movement of water and nutrients within plant cells, making sure that the plant’s food gets to the right places. It is an important part of making roots that grow properly and helps enzymes work in plant cells. It also helps the plant deal with things that stress it out, like changes in temperature, bugs, and diseases.

Studies show that potassium is very important for the health of Phalaenopsis orchid leaves during and after flowering. Plants that didn’t get enough potassium often had leaf tips that turned a different colour soon after the flower stem started to form and slowly died. Because the dirt did not have enough potassium, the plant died soon after the flowers stopped blooming.


It was interesting to learn that plants that got a potassium fertiliser had flower stems that were longer and flowers that were a little bigger than plants that didn’t get the fertiliser. Potassium probably played a big role in the plant’s growth.

Because the dirt in pots and containers doesn’t have as many nutrients, fertiliser is even more important for them. Orchids need fertiliser all the time. They are normally grown in pots with a very loose bark mix.

Do all orchids need to be fertilised?

With an orange handle on his shovel, a gardener stands by his house. He carefully pours the natural fertiliser from the shovel onto the soil around an orchid in a hanging pot while keeping his eyes on the task at hand.

Because of the way they are potted, orchids often need to be fertilised often.
Yes. Orchids need different things depending on the species. Once more, this is because of the potting mix. The roots of orchids are very sensitive. Their roots don’t do well in regular potted soil because they usually grow on rocks or on other plants.


In the wild, these plants grow in trees or on rocks, and their roots are quite large and open to the air. They get food from the air, which is high in dampness, and from the rain that falls through the trees.

Some people may not need to fertilise their orchids as much if they live in a warm area and grow them outside, in and under trees. Of course, these plants need a fair amount of fertiliser most of the time.

Different Kinds of Fertiliser

On a market shelf, different bottles and packs of fertilisers and chemicals are neatly arranged. The bright, colourful labels stand out and show off the different brands and types of farm goods that can be bought.

Even though there are many kinds of fertiliser, a soluble mix works best for orchids.

It can be scary to walk into a nursery and look around in the fertiliser aisle. All of these goods have a lot of different formulas, ratios, and ingredients, so it can be hard to pick just one. They all look like they would help your plant in some way.

There are both natural and man-made fertilisers, as well as liquid and solid forms, and compound and slow-release fertilisers. Organic fertilisers can be made from a lot of different things, like bone or blood meal, dung, bat guano,.

How to Pick the Best Formula

Orchids usually do better with a synthetic recipe that dissolves in water than with an organic granular type. Most of the time, powdered formulas are easy to mix with water in the right amount for your type of orchid.

Orchids need nitrogen for good leaf growth, so it’s important for them. Some growers use a fertiliser with more nitrogen when the plants are young just to help the leaves grow.

The Senior Curator of Orchids at the New York Botanical Garden, on the other hand, suggests a fair amount, like 20-20-20 in powder form. This well-balanced mix should give your plant all the nutrients it needs.


There are many types of speciality orchid fertilisers that can be bought in stores. These are made to meet the needs of orchids, but they can also help your plant. The NPK numbers for these are very different, and it can be hard to tell which ones are which because some have a high N, others a high P, and still others a high K.

If you’re looking for a speciality orchid fertiliser, read the label to see if it meets the needs of your plant. Most of the time, it might not be best for your species, so it will be easier to use the balanced formula.

When should you feed your orchids and how often?

A person holds a sleek white and yellow spray bottle and gently mists an orchid in a pot. While sitting on a wooden table, the orchid does very well in its calm surroundings.

Feed orchids based on what they need, which is usually once a week or every other week.
Feed your orchid about every other week while it is growing up before it blooms and while it is resting after it blooms.

Orchids need to be fertilised often, especially when they are growing, because the medium they are in doesn’t hold fertiliser well. The summer is when orchids usually grow the most. Whether this time is more in the spring or fall depends on when they bloom.


When in doubt, it’s best to err on the side of being too light. Too much fertiliser can hurt orchids, and many of them are also hurt by too much salt. If you rinse the roots well at least once a month, you can lower the risk of salt exposure.

“Weakly fertilise once a week” is a general rule of thumb that is often given. But different kinds of orchids have different needs.

Recommendations based on species

If you want to use a balanced 20-20-20 water-soluble fertiliser, we suggest you do what the New York Botanical Garden says:

Paphiopedilum: Give the plant only a quarter of the power every other time you water it. In the winter, cut back to once a month.

Phalaenopsis: Water the plant every time or every other time you water it, and give it a 1/4-strength solution every time. Rinse the roots regularly (at least once a month, or more often if you want to). This species needs food all year long.


Miltoniopsis: 4 times as strong, given to the plant every other week. This species is very sensitive to salt, so you may need to flush it more often; at least once or twice a month. Lessen how often you fertilise in the winter.

Cattleya: Every other week, wash it down to 1/4 power and give it to the plant. It’s not necessary to feed it once a week. This species needs food all year long.


Oncidium: Once or twice a month, one-fourth of the strength is given to the plant. At least once a month, flush the roots. If you fertilise this type all year, it will produce more flowers.
Given to the plant every time you water it, diluted to 1/4 or 1/2 strength. Most orchids don’t need extra nutrients as much as Vanda does. Lessen how often you fertilise in the winter.

Hard cane dendrobium: Half as strong, give the plant every other time you water it. Dendrobiums that grow on hard cane need more food than most orchids. In the winter, lower the frequency.
Orchids that are kept outside usually need to be watered more often than orchids that are kept inside.

The potting medium dries out faster when there is more wind and heat, so you may need to water an outdoor orchid every two to three days. When this happens, it’s best to assume that you shouldn’t fertilise types that say to do so every time you water or every other time. You should skip fertilising during the extra watering sessions.

No matter what, you should always flush your roots with clean water. Salts from the fertilisers can build up on the roots of plants, even ones that aren’t as likely to get sick. Most of the extra salt will be washed away with clean water.

How to Give Your Orchids Fertiliser

  • A brightly coloured orange hand carefully pours liquid fertiliser from a small white bottle into an orchid that is sitting in a lush green pot. There is a green spray bottle close. There are three different potted plants around the scene.
  • The ice cube method lets you water your orchids without giving them too much water.
  • If you want to use fertiliser on the roots of your orchid, you may need to water it down first.


  • Don’t fertilise the plant’s leaves or crown; only fertilise the roots. Crown rot can happen if water pools in the leaves and crown of your orchid.
  • As long as you use fertiliser made just for orchids, it’s safe to follow the advice for mixing it with the right amount of water. If the rules say what to do for your species, make sure you follow those suggestions if they are there.

Methods of Watering for Orchids

  • You can water flowers in a number of different ways. Some people swear by the ice cube method, which can work for people who tend to drink too much water. With this process, you can freeze fertiliser cubes that you can use on your orchid as needed.
  • When I water and feed my orchids, I like to use the soaking method because it keeps water from building up in the leaves and crown of the plant. It is very easy to fertilise this way; all you have to do is add fertiliser to the water when your plant tells you to and water normally.


  • To water orchids by submerging, fill a sink or tub with water and put the pots into the water, but only until the tops of the roots are submerged. When you fertilise this way, make sure to rinse the roots well before putting them in the fertiliser. Fertiliser burns roots that are dry more than roots that are wet. You can dip them in water before putting fertiliser on them or rinse them from above, being careful not to get water in the crown.
  • Then, mix the fertiliser with the water and put the orchid pot in it. Let the plant soak in the solution for a few minutes so that it can take in the fertiliser. It is important to give the roots time to take in water and fertiliser because the potting mix won’t hold much of it.


It’s great to fertilise orchids, and if you give them the nutrients they need, they will give you lots of beautiful flowers and waxy green leaves. There are many things you can do to make your orchid strong and healthy, but fertilising it may be the most important thing you can do to keep it happy and healthy.

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