I love orchids as they are one of the few houseplants that can flower for months on end. But what If your orchid is not blooming?
This is a very common problem I come across a lot. I myself used to struggle to get my orchid to flower again. However, I work in a garden center, so I was able to do the research and talk directly with some specialist orchid growers. They taught me a lot of tricks and tips to get my orchids flowering again.
In this article, I share with you all the techniques I have learned from the experts and some tips from my first-hand experience to understand why your orchid is not flowering and how to get your orchid to flower again.
I discovered the reason for my orchids not blooming was often because the temperature was too high at night. Orchids require the temperature at night to be 10°F cooler than the day to trigger the growth of a new flower spike and to stimulate blooming. If there is no contrast in temperature between day and night, then orchids do not flower.
Here are 7 of the most common reasons I encounter for orchids not flowering:
- Orchids require a cooler temperature at night to trigger flowering.
- Not enough light to stimulate blooms.
- Flower spikes should be cut back to stimulate the new spikes and more flowers.
- A lack of fertilizer.
- Drought Stress and Low humidity prevent flowering.
- Overwatering and the wrong potting medium stress orchids and prevent flowering.
- Orchids need a rest period in Winter to be able to flower.
Ensuring the orchid has a temperature that is 10°F cooler at night compared to daytime temperatures is one of the most reliable ways to stimulate blooms.
Keep reading for why your orchid is not flowering and how to implement the solutions, so your orchid can flower more often…
1. Orchids Require a Cooler Temperature at Night to Stimulate Flowering
This one is a tip that I learned directly from a specialist orchid grower. at first, it may seem complicated, but I can assure you it is very easy to implement, and it made the biggest difference to my orchids…
Orchids are adapted to growing in a specific sequence of temperatures with typically warmer (and more humid) day temperatures of around 66°F to 75°F (19°C to 23°C) and 61°F to 66°F (16°C to 19°C) at night. (phalaenopsis or moth orchid can tolerate day temperatures as warm as 86°F (30°C).
The difference in temperature of a cooler night followed by warmer day temperatures stimulates the orchid to grow a new flower spike and bloom.
If there is no variability in temperatures between day and night, then the orchid can grow, but it most often does not produce flowers.
This can be particularly problematic in our homes as the temperature often increases in houses in the evening with heating systems rather than cooling down, which is at odds with the orchid’s natural environment.
I had this problem myself as my indoor heating would increase the temperature in the winter and my air conditioner would dry out the air in the summer!
The solution…
To stimulate flowering, we need to emulate the temperature change between day and night in the home by placing the orchid in a nice cool location in the evening that is typically around 55°F to 66°F (12°C to 19°C) or 5°F cooler than the typical day temperature in window sill or porch for example.
I can emphasize enough that you need to keep the orchid out of the way of any sources of heat. I personally have my orchids on the other side of the room from any sources of heat.
It is important to note that the orchid can adapt somewhat to different temperature ranges, and it can usually withstand a low temperature of 55°F (12°C) at night and a maximum daytime temperature of 75°F (23°C).
What I learned is that we need to aim for a contrast in temperature of around 10°F (5°C) cooler at night for 2-4 weeks to stimulate the development of more flowers and flower spikes.
After a few weeks of cooler night temperatures, my new flower spike emerged which means my orchid can bloom again.
Pro tip: I was taught that this is the techniques used by commercial orchid growers that supply garden centers. They all expose their orchids to cooler night temperatures in nurseries to help stimulate the growth of a new flower spike so that the orchid can be in flower and look its best when it is sold which is how moth orchids can be cultivated to flower at anytime of year.
2. Not Enough Light for Flowering
Most common houseplant orchids (Phalaenopsis, often known as moth orchids) are native to tropical forests in Asia, where they grow in some filtered light or bright indirect sunlight.
It is under these conditions in bright rooms of a house that orchids flower for longer and more often. If the orchid is in a very shaded location of your home with low levels of light, it does not have enough energy to stimulate flower production.
The Solution…
So, to promote flowering in orchids, it is important to recreate the levels of light that they would typically experience in their native environment.
We can do this by avoiding placing orchids in rooms with North-facing windows, as whilst the orchid may still be able to flower in these conditions, it is less likely to re-bloom or flower to its full potential.
Whilst some filtered light is well tolerated (particularly in northerly latitudes such as New York, the Pacific North West, or the UK where the sun is less intense), it is, however, important to avoid direct sunlight for too long as the orchid leaves are sensitive and can scorch yellow or brown if exposed to too much sunlight.
This, too, can cause stress to the plant that can cause existing flowers to drop or prevent the orchid from flowering.
What you need to do is place your orchid in a nice bright room to mimic its preferred natural conditions and the orchid then can have all the energy and resources it requires to display flowers.
According to the experts, bright light is one of the most influential factors for flowering.
3. Cut back Spent Flower Spikes to Stimulate Flowering
Once the orchid has displayed its flowers on a flower spike, it usually does not display flowers again on any node that has already flowered on the same spike.
This means that if your orchid has already bloomed and the flowers have dropped off, then you can end up with a long green flower spike without any flowers and one that is unlikely to display more flowers.
Sometimes, the flower spike turns brown or yellow partially or the entire way down the spike back to the base of the plant, in which case the flower spike cannot produce a new side shoot or more blooms.
The Solution…
I can assure you that this does not necessarily indicate your orchid is dying (particularly if the rest of the orchid looks green and healthy). However, you should cut any flower spike back that is turning brown or yellow back to the base of the plant.
This should help to stimulate the growth of a new flower spike so that our orchids have the potential to display more flowers.
If the flower spikes are still green but are not flowering, then I advise cutting the spike about half an inch (2 cm) above a node or emerging shoot.
Orchids often grow a new shoot from an existing flower spike, which has the potential to display flowers.
As we discussed, to trigger the growth of new flower spikes, orchids often require a reduction in temperature during the night by around 10°F (5°C) for 2-4 weeks.
This stimulates the growth of a new flower spike and signals to the orchid that it is the right time to display flowers.
If you are unsure where or how to cut the flower spike, watch this helpful YouTube video for all the information you need:
4. Not Enough Fertilizer Prevents Flowering
The most common houseplant orchids (Phalaenopsis) are epiphytic, which means that they grow on trees in a tropical forest, and they attain a lot of the moisture and nutrients they require from the air around the roots and loose aggregate (such as tree bark and moss) around them rather than from the soil as with most houseplants.
Your orchids can often exhaust the available nutrients from the potting medium, particularly if they are in the same pot for too long, which means the orchid does not have the required resources to produce more flower spikes or display flowers.
Also, in an indoor setting, it isn’t easy for us to replicate the orchid’s natural process of attaining nutrients from the air.
The Solution…
So, for orchids to have all the available nutrients they require for flowering, it is important to use a specialized orchid fertilizer that comes in a spray form, applied to the ariel roots and the potting medium.
It is important to use a specialized product that contains all the nutrients the orchid requires at the right concentration to display blooms.
The commercial orchid growers told me that ordinary houseplant fertilizer is likely to burn the roots, so always use a customized product and apply the fertilizer every 4 weeks in the Spring and Summer to increase flowering as orchids with fertilizer often do not flower well.
5. Drought Stress and Low Humidity can Stop Blooming
Most houseplant orchids (Phalaenopsis) are tropical plants that grow in environments with frequent rainfall (although they grow in very well-draining conditions) and are adapted to a climate of higher levels of humidity.
The humidity in our homes tends to be around 10%, whereas orchids typically prefer a humidity of around 50%.
This difference in humidity causes the orchid to lose too much water from the leaves, resulting in shriveling roots, and the orchid either drops its flowers or is too stressed to produce more flowers.
Low humidity in our homes is often exacerbated by:
- Air currents are caused by central heating, forced air, or air conditioning.
- Draughts from open windows.
- Too much sunlight.
The Solution…
For this reason, I grow my orchids in my bathroom, as the humidity is often at a similar level to their native forest environment.
This has definitely boosted my orchid’s flowers. I also found the orchid flowers last much longer.
However, you can successfully grow and recreate the optimal conditions for orchids to flower in any room of the house by misting the leaves, roots, and flower stems once every day or so.
Pro tip: By misting the orchids you can create a humid micro-climate that reduces the level of water loss from the leaves and emulates the conditions of its tropical environment.
If you live in a particularly arid climate, then I recommend purchasing a plant humidifier from your local garden center (or Amazon), which allows you to control the exact humidity around your orchid to a precise level so that it has all the resources and conditions it needs to flower.
I had to use a humidifier myself when I lived in my apartment because I found the air was too dry for my tropical plants. I can say it did help to encourage my orchid to bloom and stopped the flowers and flower buds dropping off early.
(Read my article, how to Revive a wilting orchid, for more about orchids suffering from low humidity).
6. Overwatering and Saturated Soil Mediums Prevent Blooming
One of the most common mistakes when caring for orchids is to water the orchid too often.
While most houseplant orchids grow in environments with relatively frequent rainfall, they are epiphytic and grow on other trees, which means they are adapted to growing conditions with good drainage, airflow, and high humidity around the roots.
If the orchid is watered too often and the orchid’s roots are sat in a consistently damp potting medium, then the roots can rot.
The dying roots place stress on the orchid and cannot draw up and transport the nutrients and moisture around the plant that is required for flowering. (Read my article on how to revive a dying orchid if the roots are shriveling and dying or rotting.
If the orchid’s roots are not healthy the orchid does not display flowers.
The Solution…
It is important to plant orchids in the appropriate potting medium which in the case of Moth orchids (phalaenopsis) is a pine bark-based potting medium as the emulates the natural conditions of its native environment with really good drainage and allows humid air to circulate the roots.
This keeps the roots healthy and helps to mitigate a lot of the risk from overwatering due to the excellent drainage so that your orchid can flower.
Water orchids every 7- 10 days in the Spring and Summer (when the orchid is more likely to flower) and once every 10 days or so in Winter to keep the orchid healthy so that it can flower.
Moss based potting mediums can work well for growing orchids but only if you repot them regularly as I found that they tend to decompose quicker then bark based mediums which causes them to hold onto more moisture and reduce the available oxygen around the roots.
This then can cause root rot and result in a dying orchid (read my article, why is my orchid dying?).
If the orchid has been under any stress, then it is likely to invest its energy into immediate survival of the adverse conditions and regrowth to replace any roots they may have died off, in which case it can take a year or so of favorable conditions for the orchid to start to display flowers again.
(Read my article, how to water orchids to learn how often you should water orchids in different seasons and in different conditions).
7. Orchids Need a Rest Period in Winter to Display Flowers
This is one of the more unusual tips I was taught. Some orchids prefer a rest period in Winter when the temperature lowers and require less watering and no fertilizer in correlation to the lower levels of light.
This is because some species of orchid, such as Dendrobium, experience a cycle of temperatures throughout the year in their natural environment, and when the orchid is exposed to more light and warmer temperatures in Spring, it has all the resources and energy to innate flowering.
As you can tell by now, a lot of the tips and tricks for getting orchids to flower tend to revolve around our ability to emulate their natural conditions.
Orchids of all species should be watered less often at about once every 10 days during Winter as levels of evaporation and vegetative growth are lower due to the shorter day lengths, and avoid using any fertilizer during Winter.
When it is Spring, I recommend increasing the watering (to watering around once every 7 days) and using a specialized orchid fertilizer, and the orchid should be able to display more flowers.
(Read my article, how to rebloom orchids indoors).
Key Takeaways:
- The reason for orchids not blooming is usually because of not enough light, the temperature at night is too warm to stimulate flowering, or the orchid is too stressed from low humidity to produce flowers. Orchids require bright, indirect light, high humidity, and cooler night temperatures to trigger flowering.
- It is the difference in temperature between day and night that stimulates the orchid to grow new flower spikes and display flowers.
- Moth orchids do not flower again at the same nodes on a flower spike once they have flowered. Cut back the orchid flower spike down to half an inch above a developing new shoot or back to the base of the orchid if the flower spike is turning yellow or brown.
- Orchids do not flower as well without regular fertilizer, as the roots can exhaust the available nutrients in the potting medium. Use a specialized orchid fertilizer in the Spring and Summer to ensure the orchid has the available nutrients required for flowering.
- Orchids are tropical plants that prefer around 50% humidity. If the humidity around the roots, stems, and flowers are too low, then the orchid is often too stressed to produce any flowers.
- Orchids require an aerated potting medium, such as pine bark, which allows water to drain effectively. If the orchid’s roots are in a saturated potting medium or soil, then the root rot, which stresses the plant and causes the orchid not to flower.
- To get orchids to bloom again, reduce the temperature at night by 10°F for 2-4 weeks, which triggers the growth of a new flower spike and stimulates blooming. Use a specialized orchid fertilizer in the Spring to provide the nutrients to initiate flowering so your orchid can bloom again.