Growing Orchids with LED Lights
Growing orchids indoors is a fascinating pastime that is rewarded by some of the most amazingly shaped and colored blooms in the whole plant world. Technological advances with LED grow lights means that growing orchids can be easy and fun and accessible to anybody.
Read our article on Full Spectrum LED Grow Lights – Great for Orchids
We take a look at the worlds favourite orchid strains, buying, ‘How to Care’, propagation, and indoors horticulture using different lights including full spectrum LED grow lights for your orchids.
The Orchid family, Orchidaceae, is one of the largest families of flowering plants with well over 20,000 different species. That’s about four times the number of mammal species. Although some orchids are terrestrial, many are epiphytic or lithophytic. This means that they grow on trees or rocks which they use for support whilst feeding on accumulated plant detritus from around the roots. It is these orchids that are generally of most interest to the indoor orchid cultivator.
Traditionally indoor orchid growers use natural light from greenhouses, conservatories or just windows. However it is easy to grow orchids with artificial lighting such as LEDs. This means that you can grow orchids in any room in the house and make beautiful displays wherever you want.
A vivarium can often be the best way to keep orchids. You can have more control over the important factors of the immediate growing environment; temperature, light and humidity. You can group different orchids with similar requirements together (for example you could have a warm vivarium and a cold vivarium). Vivariums can also look really cool.
With so many different types of orchid, it can be difficult to know where to start. Here’s a look at some of the most popular and easy to grow orchids.
Also known as ‘moth orchids’. This is one of the most commonly available genus of orchids and one that is often found at supermarkets. Phalaenopsis are considered easy to grow and ideal for beginners. They thrive in centrally heated rooms and can flower year round.
Care – Low, medium, or bright light; water weekly or every two weeks; feed monthly with orchid fertilizer; 50oF to 75oF.
These are the long and slender orchids that you often see in florists. They have long lasting blooms and are fairly easy to grow indoors. There are hundreds of Dendrobium to choose from in a wide array of stunning colors.
Care – Medium or bright light; water weekly or every two weeks; feed monthly with orchid fertilizer; 50oF to 75oF.
Another commonly found genus of 113 or more species that is also a suitable choice for beginners. Cattleyas are known for their big showy flowers.
Care – Medium or bright light; water weekly or every two weeks; feed monthly in spring and summer with orchid fertilizer; 50oF to 75oF.
This genus is very similar to Cattleya and shares the same genetic origins in Central and South America. Laelia typically bloom in lower light conditions in autumn or winter.
Care – Medium or bright light; water weekly or every two weeks; feed monthly in spring and summer with orchid fertilizer; 50oF to 75oF.
Also known as the Slipper Orchid. There are around 60 species that are known for their beautiful forms and colors. Paphiopedilum are mostly terrestrials although some are epiphytes or lithophytes.
Care – Low, medium or bright light; water weekly; feed monthly in spring and summer with orchid fertilizer; 50oF to 75oF.
These orchids present clusters of small delicate flowers that are very attractive. Some are very fragrant, adding another dimension to your orchid collection.
Care – Medium to bright light; water weekly or every two weeks; feed monthly in spring and summer with orchid fertilizer; 50oF to 75oF.
Cymbidium orchids are known for their waxy flowers and ease of care. They generally flower in colder temperatures, often in late winter/early spring.
Care – Bright light; water weekly; feed monthly in spring and summer with orchid fertilizer; 50oF to 75oF.
Like all of the best pastimes, growing orchids is a subject to which there is no end. You could spend your whole life dedicated to it (many do) and still not know it all. Having mastered the easier to grow varieties, many orchid enthusiasts like to move on to more difficult to grow species like the Pink Lady’s Slipper (Cypripedium acaule)
This wild orchid from the eastern states of the USA is one of the Lady’s Slipper orchids. Unlike many of the others though, this one is particularly hard to cultivate indoors. In the wild it shares a symbiotic relationship with a soil fungus which is essential for its growth and reproduction.
If you choose one of the above types of orchid to start with, you will find that orchids can be surprisingly easy to grow. Growing under artificial lights such as HID, CFL or LED will give you more choice as you will be able to attempt some of the orchids that prefer stronger lighting. It will also enable you to flower your orchids more easily as low lighting is one of the most common causes of non-flowering.
Orchids mostly prefer high air humidity, around 60% to 80% in summer, dropping to around 30% in the winter. At the same time, they are prone to root rot and prefer a quick draining medium that allows the roots to dry out rapidly after watering. The optimum growing medium varies from genus to genus but normally consists of fir bark, coconut husk, sphagnum moss or a mixture of these.
The growing medium of your orchids need to completely dry out between watering. Orchids use the dry period between watering to take on oxygen through their roots which they use to convert stored sugars to energy. A waterlogged growing medium stops them from doing this.
Check the medium before watering to see that it has completely dried out. The medium should be bone dry and crack under your fingers. If it still holds any moisture, it is not yet time to water your orchid.
For most orchids, watering around once per week is the norm. Water them from the top and allow the water to run through, removing any that collects in the run-off tray. You should mist the foliage and aerial roots daily or every other day. If you think your orchid is too dry, dip the pot in a large container full of tepid water and leave for around ten minutes to allow the roots to suck up as much water as they can.
Each of the different orchid species will have its own ideal range of growing temperatures. To produce healthy, long-lasting blooms, orchids require a day/night temperature fluctuation. Without this, orchids may grow lots of healthy looking foliage but will often refuse to flower. As a general rule for most orchids, a night temperature of 60oF – 62oF (15oC – 16oC) is ideal, although temperatures as low as 55oF (12oC) should not harm your plant. Day temperatures should fall somewhere between 70oF (21oC – 27oC) and 80oF. Higher temperatures are sustainable for short periods but be sure to provide proper humidity and air circulation.
In their natural outdoor environment orchids are normally subjected to a breeze. This is crucial to bringing them fresh, CO2 rich air. It also helps them to dry out their roots and helps to avoid fungal and bacterial infections. Without good air circulation an orchid is prone to rot and, in the worse cases, death.
Providing good ventilation for your orchid is easy. In the summer time, try to make sure there is a window open so that the room receives lots of fresh air. If you can’t open a window, or if your orchid is in a vivarium, use a small oscillating fan to make sure that there is some air movement. Don’t train the fan directly onto the orchid as this may shock and chill the leaves and roots. Just allow the fan to move the air about and make sure that there is a constant supply of fresh air to the growing environment.
Feed your orchids about once a month during the spring and summer, tailing off and giving them a rest during the winter. Give them a proprietary orchid fertilizer.
Orchids can be quire delicate plants. It is easy to burn the roots by giving them too much fertilizer. It is often a good idea to give them a little less than the recommended dosages. Orchids are adapted for periods of drought and low nutrition. Never feed an orchid with damaged roots. This will only exacerbate the problem.
There are just about as many types of fertilizer available as there are orchids and some of the hype and pseudo science can be frustrating. To help you cut through the jargon bear some of the following points in mind.
Orchids like a lot of light, but they do not like direct sunlight. Using artificial lighting for orchids gives you the advantage of being able to control the light better and apply strong light that is not as strong as sunlight. Lack of flowering in common household orchids is often a problem of low light conditions.
There are many different ways in which light is measured and this can cause some confusion to the new orchid enthusiast.
Firstly, you need to consider the right color of light.
The light that horticulture requires to grow and flower is known as P.A.R. This is Photosynthetically Available Radiation and refers to the light spectrum that is usable by the plant to grow. P.A.R covers the ‘visible light spectrum’ and is divided up into wavelengths which are measured in nanometers (nm).
The PAR spectrum runs from about 400nm to 750nm. The blues have a wavelength between 400nm to 500 nm. The reds have a longer wavelength of 680nm – 750nm.
PAR has two peaks that are important to all horticulturalists. 450nm – 495nm (blue), and 620nm – 750nm (red). These wavelengths promote vegetative growth and flowering respectively.
So, broadly speaking, red end light promotes flowering and blue end light promotes vegetative growth. Light that is strong in these wavelengths is best for growing plants. Plants don’t absorb much green light and this is mostly reflected, hence the green color of leaves.
Many indoor horticultural lights have their color measured in Kelvins. This is a measure of the temperature of light based on the theory that different colors of light produce different temperatures. Indoor horticulturalists are trying their best to emulate natural sunlight, which contains all wavelengths. In Kelvins we could consider it as running from cool, at 6500K to warm at 2700K.
For best growth with orchids a bulb of around 5000K is optimum. If you can supply supplemental lighting at around 2700K it will provide a fuller spectrum and may help to promote blooming.
A good grow light we will cover the P.A.R spectrum entirely from 420 to 750 nm and is known as a full or broad spectrum grow light.
The other way to measure light is to measure its intensity. The intensity of light is obviously important when growing orchids. Orchids come from a very wide variety of habitats and climate zones. They also mostly live in shaded locations so the lighting requirements can vary widely between different orchid varieties.
The subject of lighting intensity can also confuse people. There are many ways of measuring it. Most grow lights measure this in Lumens, whereas orchid requirements are quite often listed in Foot Candles (fc). Try using this handy convertor to compare the lighting requirements of your orchids to any grow lights you might be considering.
Yes, it can be a bit tough to understand lighting but really you can give a plant as much light as possible, just making sure you do not burn or overheat it.
More intense light indoors can encourage your orchids to perform better. But how do you know how much light is enough and how much light is too much? Careful observation of your plants foliage will allow them to tell you.
In the picture below, the orchid on the left is not getting enough light. The orchid on the right is getting just the right amount.
Some orchids may begin to get a red flush under too much light. A little of this is not a bad thing and can encourage more vigorous growth. Keep an eye on it though, and if it deepens, lessen the light.
Lighting times for orchids is a subject of fierce debate. A good rule of thumb is to aim for 15-16 hour days, reducing this by a couple of hours during the winter months. Whilst there is little concrete research about orchids and photoperiod, it is known that with some orchids, such as Cattaya and its hybrids, a short photoperiod can induce flowering.
Recent advances in LED grow lights have seen a surge in their popularity amongst indoor cultivators of all kinds. Superior energy efficiency and the ability to create customized spectrums have revolutionized indoor horticulture, both commercially and for hobbyists.
The best type of LED grow light will feature full spectrum lighting. This means that white light is transmitted that covers the entire spectrum, not just in individual wavelengths as with some of the lower end LEDs.
The SK450 runs at 250 Watts (true draw) which is equivalent to 500W of HID lighting and will cover an area in excess of 16 sq ft. The SGL6 is equivalent to 50W of HID power, draws only 25W and will comfortable light smaller displays of 3 – 4 sq ft.
HID lighting is powerful and can be effective for growing larger displays in a closet or spare room. Orchids like some of the larger Vandya or Dendrobium will thrive under HIDs. Metal Halides will provide a cooler spectrum which is a better match for the tropical sun. A typical MH lamp will peak at around 450nm to 500nm but also provide a wide coverage on either side of this peak.
Supplemental High Pressure Sodium (HPS) lighting can provide more red end light and help to create a fuller spectrum. HPS lighting alone has too narrow a spectrum to be of much use. It peaks dramatically at around 570nm and provides a little extra red end light and virtually no blue end light at all.
A 400W Metal Halide would be suitable for most home growers. Placed about 2 – 3 feet above your plants it would provide enough light for a table top display.
Whilst HID lighting is powerful it is also quite inefficient. It creates a lot of heat, which will need controlling, especially for orchids which prefer cooler conditions. It can also cost quite a lot of money to run an HID light.
CFLs grow lights are very good for lighting orchids and probably the most commonly used by orchids growers. The light is less harsh and less heat is generated than with HID. Giving you more control over the temperature of the room. However these days most armatures are moving towards what the pros use, LEDs.
To make the most of CFL lighting you will need to have different, complimentary bulbs to complete the spectrum and provide the light your orchids need. A mix of cool white (4000K) and warm white (2700K) should do the job and are cheaply and easily available.
Suitable CFLs run from a 45W which would be suitable for supplemental lighting or small single plant displays to 250W which would be suitable for a display of around a dozen plants, depending of course on which type of orchid you are growing.
Many orchid growers use banks of smaller bulbs. This is not only more efficient that using bigger bulbs (2 X 125W bulbs provide more available light than 1 X 250W bulb), you can also cover a larger area. It is also possible to make a feature out of the lighting itself. Check out this CFL set up which uses CFLs to augment light from a window.
Propagating orchids from seed is a difficult task and one that is not suitable for beginners. Unlike most other plants, orchid seeds do not carry the store of nutrition required for them to establish roots and leaves and become self sufficient. Instead, orchids rely on mycorrhizal fungus that is present in its immediate growing environment to provide the all nutrition required to grow.
Most orchid growers begin with bought in orchids and then use asexual, vegetative propagation processes to divide these into multiple plants to extend their collection. There are three main types of vegetative propagation that are suitable for orchids:
For a lot of people, growing orchids as a hobby begins with being given one as a gift. The beauty and elegance of the flowers, the interesting variety of habitats and the sheer volume of different species available soon lead on to wanting to learn more and try keeping different varieties. Here is a good resource to help you start looking for orchids.
Remember that some orchids are rare or protected. If you start buying orchids from e-bay and other internet auction sites, make sure that you choose ones that a freely tradable and not harmfully or unsustainably collected.
We have a lot of customers from all around the world from Sweden to Australia and of course the USA successfully growing orchids with our full spectrum grow lights. The low electricity costs, full P.A.R coverage and solid construction of our lights means that these are a perfect replacement for the old school HID and CFL lights.