Fertilizing your orchids

Orchids require the correct balance of factors that influence their healthy growth. Fertilizing your orchids can be a real game changer if you get it right. Your orchid will be in robust form and will bloom generously during the season. The trick is in tweaking it to suit your grow conditions. In this post, I am touching upon the fundamentals of fertilizing orchids and giving tips on getting good results.

Aerangis biloba – first time blooms under my care

My first three years into the orchid hobby were spent on learning how to tend to my orchids. While I had a sizeable and healthy collection, the blooms were few and far between. My family even began convincing me that I had been duped by the sellers and these plants could bloom well only in green houses.

But YouTube offered many success stories of growing orchids at home, and I knew that I had to keep trying out new ways to increase blooming. I kept fertilizing my orchids once a week with concentrations of 200 TDS of NPK fertilizer, but it just did not seem to be enough. The few orchids that bloomed produced one or two flowers. That’s when I realised that perhaps they required more frequent application at higher concentrations.

I got new insights on nutrition for orchids by watching Rick L’s Orchids channel on YouTube. His explanations seemed logical and his orchids looked healthy and bloomed abundantly. I laid down a similar strategy for fertilizing my orchids. I fine-tuned it to suit my climatic conditions and my orchids are responding well by producing more blooms with each passing season.

However, I have achieved results after experimenting repeatedly. I am sharing my insights and tips on applying fertilisers that helped improve blooming.

Basic orchid care comes before fine-tuning your fertilising routine

Cattleya labiata Coerulea blooming for the first time

Getting a beautiful bloom show is every orchid lover’s dream. And while some orchids put on their best show without any special care, the majority of orchids, especially cultivated hybrids, require the right balance of light, moisture, temperature and nutrition to coax them to bloom. From my experience as an orchid hobbyist, I have realised that missing out on even one of the above mentioned factors will affect the outcome of an entire year’s care. So when we talk about fertilising your orchids, it is utmost important that you do not overlook basic factors such as suitable light, moisture and temperature to achieve good results.

Orchids are mostly epiphytic, and in their native environment depend on the trees on which they grow to provide them with nutrition – not as parasites sucking the sap of the tree, but by absorbing the the bird and insect droppings that run down the trees along with rain water. Rain water, which is rich in Vitamin B12 producing bacteria and fungi, also helps the orchids absorb these nutrients, thereby optimally meeting their requirement of Nitrogen, Phosphorus and Potassium. Along with these, Calcium, Magnesium and other trace micronutrients are also made available to the orchid.

When there are no rains, the aerial roots absorb moisture from the air and thereby help the orchid survive. The orchids also have thick fleshy pseudobulbs and leaves, which serve as reservoirs of stored energy. This is used up by the orchid to grow and bloom during periods of drought.

With this understanding, we need to now provide nutrition in similar ways and mimic nature. Of course, with the growing number of special hybrids, the need for fertilising year round has become a norm as these orchids produce large blooms and also have more number of spikes and blooms. However, the basic principles remain the same, wherein the orchid requires maximum nutrition during its growth period and the stored nutrients get utilised during the bloom period. However opinions differ and some hobbyists continue to feed minimally or normally even while they are in bloom.

About orchid fertilisers

Initially, the Brassocattleya Jimminey Cricket did not bloom due to low concentrations of fertilizer. After tweaking the concentration, it bloomed repeatedly.

Orchids need to be fertilised when they are in vegetative growth. This is crucial for their proper development and blooming. So when you observe new leaf or root growth or the development of a bud spike or new shoot, then you need to feed it with fertiliser to meet its increasing requirement for growing new tissue.

To this end, we should apply a fertiliser that is rich in basic building blocks such as Nitrogen, Phosphorus, Potassium as well as Calcium, Magnesium and other trace micronutrients. Most fertilisers have these components in a form that can be easily absorbed by orchids.

Orchid fertilisers can be grouped into Chemical and Organic fertilisers. Chemical fertilisers are those that are manufactured in an industrial process and are in a chemically pure form, either in a powder form or as a solution. Examples of these are NPK 20:20:20 and solutions of Calcium Nitrate and Magnesium Sulphate (Cal-Mag).

Organic fertilisers, on the other hand, are made from plant or animal matter and even their excreta. These substances are in the form of bio-compounds that need to be further broken down by microbes in the medium to get absorbed by the plants. Examples are sea weed kelp, fish fertiliser and other home-made fertilisers such as soaked rice water, green tea extract, garlic extract, banana peel extract, diluted coconut water etc.

While the above fertilizers enhance vegetative growth, commercial growers use bloom booster fertilizers to improve bloom production. This is an NPK type of fertilizer with a higher proportion of Phosphorus. However, speaking from personal experience, applying bloom boosters has not enhanced blooming in my orchids. In fact, my orchids began blooming well when I eliminated bloom boosters. NPK 20:20:20 application helped my orchids bloom just as well.

How often should you fertilise?

Include weak fertilizing every week with a number of different fertilizers to provide all types of nutrients and micronutrients

Well, there is no one-size fits-all answer to this question. It all depends on your climatic conditions, your grow area – whether indoor or outdoor, your frequency of watering, the medium in which the orchid is growing, ambient temperature, etc.

Generally speaking, you can fertilise once a week, or you could divide the same dose into half and do a twice weekly routine, if you are watering your orchids twice a week. Remember to flush your orchids with plain water in between to avoid build up of fertiliser. Initially, I fertilised my orchids once a week, but that just didn’t get them to bloom. After going through Rick L’s videos on YouTube, I began fertilising my orchids twice a week below recommended concentration, but I varied the type of fertilizer I applied so that they absorbed different types of nutrients and trace minerals.

For instance, I apply NPK 20:20:20 along with seaweed kelp once in 15 days. In between, I apply organic home-made liquid fertilizer twice a month and Silicon dioxide fertilizer once a month. In between these, I apply mild doses of Calcium nitrate and Magnesium Sulphate together twice a month. This method of low dose fertilizer application, either stand-alone or in appropriate combination, has helped me improve blooming in my orchids. I will cover this aspect at length in a separate post.

Applying the right quantity of fertiliser to your orchids

Orchid hobby guide
Apply optimal concentrations of fertilizerto coax your orchid to bloom

Having said this, there are some ground rules to begin with. Doing it right and understanding the basics of applying the right quantity of fertiliser is important. Following the recommended doses and frequency as advocated by the fertiliser manufacturer helps if your fertiliser is designed for orchids. But if it is a general plant fertiliser, it is always better to start with half the recommended dose and increase or decrease it based on the response of your plants.

If the leaf and root tips start drying out, it is an indicator of leaf tip burn, then it means the concentration of salts is too high. The quantity of fertiliser needs to be reduced in such cases. However, if the orchids show healthy development, then the dosage caters optimally to the plant’s nutrient requirement. On the other hand, if the plant shows no improvement in growth, and new growths die back or have stunted growth, then you need to increase the dosage gradually until your plants become healthy and lush green. These healthy growths will then produce blooms during the season.

Concentrations matter based on size of orchid, the thickness of the leaves and roots. Orchids with thick, spongy velamen and thick leaves such as Vanda and Phalaenopsis orchids require regular doses of fertiliser like a teaspoon of fertiliser in 5 litres of water. But for thin leaved and thin velamen-root orchids such as Oncidiums, Tolumnia, Catasetums and Bulbophyllums and others, the dilution can be reduced by adding half teaspoon of fertiliser in 5 litres of water. If the orchid fertiliser is not improving growth, then you can marginally increase dosage until these orchids start developing healthy roots, leaves and shoots.

When not to fertilize

You should fertilise your orchids during periods of active growth. This is usually during the warmer summer months and rainy season. Your orchids will produce new roots, leaves and new pseudobulbs. The right amount of fertiliser application will help in their healthy development. However, as ambient temperature drops down with the advent of winter, you need to minimally water and fertilise your orchids based on their growth.

There would be a few exceptions such as Oncidiums, which would start producing new growths. In such cases, you can continue fertilizing these orchids. However, a major portion of your collection would be done with the growth period, would remain dormant and conserve energy for the bloom period in spring. In such cases, water them sparingly and allow them to rest in a near-dry condition. Don’t worry if you see the pseudobulbs shrivelling. That is a part of their cycle even in the wild. Once the temperatures rise back to normal, the orchids will push out new growths such as sheaths, spikes, new shoots and roots. At this stage, you need to resume watering and fertilizing.

Do not fertilize if your orchid is not doing well

Another instance of when you should avoid fertilizing your orchid is when your orchid is sick or has undergone a shock such as a transplantation shock or sudden change in ambient environment. This could be when you buy a new orchid and bring it home, repot it or if it has some underlying infection and is therefore not growing normally. In such a scenario, it is best to not increase stress by fertilizing it during this period. Gradually, when the orchid shows sign of recovery and growth, you can begin fertilizing it with very low concentrations to begin with and gradually resume to normal levels.

As you tweak your fertilizing method, your orchids will bloom in significant numbers

With these fundamentals in mind, you can go ahead and experiment with different kinds of fertilizers. You can check out which ones are most suited for your grow conditions. Remember to keep it optimal. Your orchids will thrive and reward you with healthy blooms during the season.

Happy growing!

Winter Care for Orchids

Changing seasons need you to bring in modifications to the way you care for your orchids. Making small adjustments in your orchid care routine during winter will ensure that you get healthy and beautiful blooms during spring. Read on to know more about the changes you need to make to provide the best care suited for your orchids during the colder months.

The last of the rains have receded and your orchids have been thriving so far due to the increased humidity and goodness of rainwater. There has been a spurt of new growths throughout the season and now, as winter sets in, days tend to get shorter, and slightly warmer and dryer (due to the relative proximity of the earth to the sun in October).  Night time temperatures begin dropping and nights get longer. These changes in the cycles of light and darkness, coupled with cool dry breezes, induce changes in the growth of orchids.

Deciduous orchids drop their leaves when temperatures drop

In nature, orchids, after the rainy season, are subject to lower levels of moisture and humidity, along with cool dry breezes during winters. The orchids adapt quickly to these adverse changes by slowing down their pace of growth or becoming fully dormant. Deciduous orchids shed their leaves and survive using the energy stored in their canes.

What to expect

These climatic changes have a profound effect on your orchid’s growth and development. While the care tips for your orchids vary from season to season, come winter, and you need to regroup your orchids according to their water and sunlight requirement. This modification is necessary since various sub-classes of orchids have varied requirements.

Phalaenopsis orchids need a drop in night time temperature to develop bud spikes

While Phalaenopsis and Oncidium orchids react to the drop in temperature and daylight hours by developing flower spikes, there are others like Dendrobium and Catastinae orchids that go into dormancy during the winter months. Cattleyas and Oncidiums continue to push out new growths, albeit a little slower due to falling temperatures. This prepares them for the spring blooming season, when they begin developing sheaths and buds prolifically as the days grow warmer.

Getting familiar with these changes in different classes of orchids will seem complicated at first, however, being proactive about learning about your orchid’s care requirements will help you organise your orchids in such a way that you will find it effortless to look after your growing collection of orchids.

Making small adjustments in your orchid care routine during the winters will ensure that you get healthy and beautiful blooms during spring. Here are a few pointers that you would need to consider to provide the best care suited for your orchids during the colder months:

Winter care tips for your orchids

Reduced watering and fertilizing

Reduce watering and fertilizing to match your orchid’s growth rate

When the rains recede and autumn sets in, there would be a steady drop in temperature and humidity levels. The dry winter months have shorter days and longer nights. Less heat and shorter days coupled with night time temperature drops means that now the medium will not dry out fast. Hence you need to reduce watering.

Second, you need to watch out whether the orchid is in active growth mode, wherein it continues developing new growths, buds, spikes, roots, etc. If this is the case, then you can water and fertilize the orchid. But always ensure that the fertilizer is half or even quarter of the recommended strength. This will meet your orchid’s needs during these months.

If you continue providing full strength fertilizers, it may lead to root burn and the orchid has a high chance of developing rot issues due to the high levels of fertilizer and moisture being retained in the medium over a prolonged period. Therefore, always allow the medium to dry out before you water the orchid again.  

While orchids thrive in humid conditions, they do not like being potted in wet medium that does not allow the roots to breathe freely. Well ventilated pots with slits and holes along with proper drainage will promote a wet-dry cycle that is conducive for the orchid’s growth.

Seedlings require a moist environment, so maintain adequate moisture during winter

If you have seedlings in your orchid collection, then you will need to ensure they get watered adequately. Do not allow the medium to dry out fully before watering again. They have sensitive roots that need moisture for their growth. Also do not overwater them as this will lead to root rot.

Temperature and sunlight changes

Shift your orchids indoors if you have extreme drop in temperature during winter

If your winters are marked by frost, snowfall and extreme cold conditions. Then you would need to shift your orchids indoors or in more hospitable conditions with sufficient heating and even artificial lighting. This will ensure that they survive, and even grow and bloom, despite extreme climatic conditions outside.

If you are staying in a warm tropical climate like mine, with very little fluctuation in temperature and humidity, then your orchids will continue to actively produce new growths and buds despite slight drop in temperature. In such a scenario, you need not alter your care regimen during the winters. You can, at the most, reduce your frequency of fertilization since there is a drop in pace of growth in the cooler months. Also, the day-time temperatures are pretty high due to the proximity of the earth to the sun in October- November.

So your orchids need to be kept cool, moist, but not soggy, and fertilizing strength should be reduced in order to prevent root burn. I fertilize my orchids every fortnight instead of weekly as the temperatures dip a little beginning November. I resume weekly fertilizing in March as temperatures rise and orchids resume active growth mode. Moreover, I separate out my winter resting orchids and lightly mist them once a week if I find them too dehydrated.

Cool winter rest

My winter resting orchids get an occasional spritz of water that provides minimal moisture

Deciduous orchids like Dendrobium species and Nobiles as well as Catasetums drop their leaves during winter. This is a natural response to the changing season. Since there is very little ambient moisture, the orchid tries to conserve the moisture that it has stored in its canes (rain water and nutrients absorbed during the rainy season plumps up their canes). 

To prevent loss of moisture through transpiration, the orchids drop their leaves and stop further growth. Once the winter months are over, the warmer temperatures promote new shoot and root growth, and the plant prepares for the bloom season in spring.

Some of the orchids that require a cool winter rest are Dendrobium lindleyii, Dendrobium anosmum, Dendrobium aphyllum, Dendrobium nobile orchids, and many others.  Even Brassavolas and Brassocattleyas appreciate a cool winter rest for a good bloom season, although they do not shed their leaves. Their thin, long succulent leaves are structurally adapted to prevent loss of moisture though transpiration.

However, look out for signs of dehydration in the form of wrinkled leaves and shrivelled canes in your resting orchids. Lightly spritzing these orchids once in a while will be sufficient to keep them hydrated. Do not worry about the dehydration too much. Once you begin watering them in spring, they tend to fill out again.

A basal keiki or baby plant developing instead of a spike due to overwatering and fertilizing in winter

If you continue watering these winter resting orchids, then their canes may develop rot issues since the medium remains soggy for long periods. If they survive this ordeal, then they will produce a whole lot of keikis (baby plants or basal growths), instead of producing blooms. This would be real disappointing after all the care you have put in throughout the year. Therefore it is important that we refrain from watering them for at least three months during winters.


Use pine bark mix or a similar well-draining medium and ensure it dries off between watering

Since there is a drop in temperatures during winter, the medium tends to dry out more slowly than it would during the warmer months. Always water enough to keep the medium moist, but ensure it does not remain soggy. Provide good ventilation by mixing chunky bark with moisture retentive medium. This will ensure the right balance between moisture and aeration in the medium.

Use small size pots or pots with slits or holes on the sides for adequate ventilation. Also ensure that there are drainage holes at the bottom to allow excess water to drain out. In the case of orchids that are mounted on wood or any other medium, you need to ensure they get watered every day, unless they are winter resting orchids.

For more information on this aspect, check out my post on ‘Everything you wanted to know about ORGANIC MEDIA FOR GROWING ORCHIDS

When your orchids have new growths

Water and fertilize your orchids based on their growth rate

With a drop in temperature, there is a slowdown in growth in your orchids until it comes to a standstill in extreme cold temperature. Depending on the temperature drop in your surroundings, you need to observe whether your orchid is continuing to grow or it has slowed down. You need to alter your watering and fertilizing schedule accordingly. Reduce fertilizing if your orchids show a slowdown and stop fertilizing those that show no signs of growth. Continue watering them minimally to ensure they do not get overly dehydrated. You can start watering and fertilizing them gradually in a graded manner as the temperatures begin rising again during spring.

Keeping pests at bay

Mealy bugs are rampant in the drier and dustier months

As temperatures drop, there is reduced humidity. The dryness and dust that settles on your orchids outdoors gives rise to problems of pest attacks. Spider mites, mealy bugs and scale attack become rampant in the drier months during winter.

Keep your orchids clean and dust free by spraying them with a solution of mild liquid dishwash soap. Alternatively, you can gently wipe the leaves with a sponge or dampened tissue. Don’t worry if some moisture enters the crown. You can draw out the moisture using a folded or rolled tissue. Allow to dry fully under a fan or in the open breeze. This will facilitate quick drying and prevent rot issues.

Scale is also a menace during the winters

In case you have any of these pest infestations, isolate these plants and treat them with a suitable solution to eliminate them completely. You can use diluted rubbing alcohol to treat scale and mealy bug infestation and use mild soap solution with a little paraffin oil to keep spider mites at bay.

For more details on identification and treatment of pest infestations in orchids, read my post on ‘How to SAVE YOUR ORCHIDS from pests and diseases’.

Enjoy the blooms on your Phalaenopsis orchid during winter

With these handy winter care tips, you will be able to organise your care routine better.

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Till my next, happy growing!