Had an orchid growing-related question burning in the back of your mind? This is the section for you – here you can find the wisdom and knowledge of our members presented in a ‘question and answer’ format. If you don’t find your question addressed here, please use the form below to ask our experts!
FAQ Answers
Click the question to view the answer.
Why won’t my orchid bloom?
This is probably the most commonly asked question, unfortunately there is not a simple answer. It is dependent on the type of Orchid you are trying to grow and the conditions in your area. Orchid growing is like real estate. It is all about location, location, location. Essentially orchids need to be in an area that resembles the micro-climate where they are from for them to thrive. And the components of successful growing and re-blooming orchids are multi-factorial. It depends on the kind of orchid, the amount of light, water, temperature that the individual orchid needs to thrive. And then sometimes on subtler components like how much fertilizer, when, does it need to be continually moist, does it need to dry out between watering, and does it need a rest period.
How do I increase the humidity?
There are different ways to do this depending on your growing situation. You want the humidity around the orchid plant to be between 40%-70%. In general, you want the humidity (along with the temperature) to be lower at night.
In the home one of the easiest ways is to fill trays or saucers with gravel or pebbles and put water in them. Put the plant ABOVE the water, never in it. Make sure to use a non-porous container like a plate or saucer if you are putting your plants on a wooden surface or a surface that will be damaged by moisture.
Humidi-Trays are an excellent tool to do this. These are plastic trays with a plastic fitted grate (they come in various sizes). They can be set on a window sill or table top. The plants sit above the water that is held in the tray below. The trays hold the water, the grates hold the plants and the evaporation of the water increases the humidity around the plant.
Other ways of increasing humidity around the plants is by using hand sprayers of various designs (handheld or larger compressed sprayers) and periodically mist the plants with water. If you are growing in an outdoors or in a greenhouse you can use a misting system that is either controlled by a timer or by a humidistat.
In the home one of the easiest ways is to fill trays or saucers with gravel or pebbles and put water in them. Put the plant ABOVE the water, never in it. Make sure to use a non-porous container like a plate or saucer if you are putting your plants on a wooden surface or a surface that will be damaged by moisture.
Humidi-Trays are an excellent tool to do this. These are plastic trays with a plastic fitted grate (they come in various sizes). They can be set on a window sill or table top. The plants sit above the water that is held in the tray below. The trays hold the water, the grates hold the plants and the evaporation of the water increases the humidity around the plant.
Other ways of increasing humidity around the plants is by using hand sprayers of various designs (handheld or larger compressed sprayers) and periodically mist the plants with water. If you are growing in an outdoors or in a greenhouse you can use a misting system that is either controlled by a timer or by a humidistat.
How much light do I give my orchid?
Light requirements are another set of frequently asked questions. In an overall sense most orchids like bright light. Many orchids are epiphytes growing in trees above the forest floor. How much they need is completely species dependent, and it varies widely.
Phalaenopsis and Paphiopedilum like it about 70-90% shade. For Vandas most Dendrobiums and some others you will need very bright conditions from 30 % shade up to full sun. For Cattleyas and Oncidiums from 50-70% shade.
One way to check your light levels with some confidence is to quantify it by using a light meter to see what will grow best in your situation. Light is measured in foot-candles. There are a number of resources that specify what the light requirements of certain orchids are. JODOS members can help answer these questions at a monthly meeting.
Phalaenopsis and Paphiopedilum like it about 70-90% shade. For Vandas most Dendrobiums and some others you will need very bright conditions from 30 % shade up to full sun. For Cattleyas and Oncidiums from 50-70% shade.
One way to check your light levels with some confidence is to quantify it by using a light meter to see what will grow best in your situation. Light is measured in foot-candles. There are a number of resources that specify what the light requirements of certain orchids are. JODOS members can help answer these questions at a monthly meeting.
What temperatures do my orchids want?
There are many species of orchids and they are found at all temperature extremes. So again it is very dependent on the kind of orchid you are growing and what you can supply in terms of an ideal environment. In general, orchids prefer average home temperatures of 13 – 17 degrees C at night in winter and 24 – 30 degrees C during the day will suit most orchids.
Cool orchids from the higher mountains like a minimum of 10 degrees C, intermediate orchids from the plateaus like it more like 13 degrees C minimum and warm orchids from the lowlands like it more like 18 degrees C minimum. If you can figure out how to keep your orchids near the temperatures that they need the orchids will be happy.
Cattleyas, Phalaenopsis, Oncidiums, Vandas and most Paphopedilums are considered warm growing and need a range of 15 – 32 degrees C. Other orchids are considered to be cooler growing genera like Cymbidiums, Odontoglossum, Miltonia, Masdevallia and Phragmipedium. Many orchids are adaptable and it is an easy matter to put cool growers a little closer to a window where the temperature will be lower in the winter or a warm grower back from the window where the temperature will be higher. It is a matter of finding the right micro climate in your home or growing situation. If you are comfortable, then the orchids often are too.
Cool orchids from the higher mountains like a minimum of 10 degrees C, intermediate orchids from the plateaus like it more like 13 degrees C minimum and warm orchids from the lowlands like it more like 18 degrees C minimum. If you can figure out how to keep your orchids near the temperatures that they need the orchids will be happy.
Cattleyas, Phalaenopsis, Oncidiums, Vandas and most Paphopedilums are considered warm growing and need a range of 15 – 32 degrees C. Other orchids are considered to be cooler growing genera like Cymbidiums, Odontoglossum, Miltonia, Masdevallia and Phragmipedium. Many orchids are adaptable and it is an easy matter to put cool growers a little closer to a window where the temperature will be lower in the winter or a warm grower back from the window where the temperature will be higher. It is a matter of finding the right micro climate in your home or growing situation. If you are comfortable, then the orchids often are too.
How often should I water?
This is totally dependent on the kind of orchid you are growing and your particular growing situation. It is something that has to be learned. You can start by studying the type of orchid you have as well as the environment you are in. Generally, Cattleyas, Dendrobiums, Encyclias, Epidendrums, and others need to be allowed to dry between waterings, but others such as Phalaenopsis, Paphiopedilums. Phragmipediums & Miltonias need to stay moderately moist. All seedlings on the other hand need to stay more moist and warmer at nights than adult size plants.
Watering more is appropriate when the light and temperature is higher, or the humidity is lower. Plants in baskets or on mounted on slabs generally need more water. Plants in small pots or in clay pots might also need more water. When there is more air circulation (which orchids love) or if the plants have thinner leaves watering more might be appropriate. Watering less is better when there is less light and the temperature is lower. Or when the humidity is higher.
Plants in plastic pots or larger pots can require less water. Watering less might be more appropriate when there is less air circulation or when the plants have thicker leaves. And it is important to remember that some orchids like certain kinds of Dendrobiums require a rest period where they receive no water at all (typically in winter). Again, it is all about the kind of orchid that you are growing.
Watering more is appropriate when the light and temperature is higher, or the humidity is lower. Plants in baskets or on mounted on slabs generally need more water. Plants in small pots or in clay pots might also need more water. When there is more air circulation (which orchids love) or if the plants have thinner leaves watering more might be appropriate. Watering less is better when there is less light and the temperature is lower. Or when the humidity is higher.
Plants in plastic pots or larger pots can require less water. Watering less might be more appropriate when there is less air circulation or when the plants have thicker leaves. And it is important to remember that some orchids like certain kinds of Dendrobiums require a rest period where they receive no water at all (typically in winter). Again, it is all about the kind of orchid that you are growing.
What's the best fertilizer to use? How often should I fertilize?
Most orchid growers have a favourite fertilizer. Really here it is to each his (or her) own. A good rule to start with for beginners is half of the recommended strength of a balanced 20-20-20 will work just fine.
I do change my formulations using a higher Nitrogen fertilizer (for leaf growth) from August to January and a lower Nitrogen, higher potassium fertilizer (to support flowering) from February through May. In general, do not fertilize in the wintertime. As you learn the needs of the kind of orchids that you grow you may want to fine tune your formula depending on your water quality and the potting media you use. The adage is “weakly, weekly”.
That said, it is best to fertilize about once a week or two in the spring and summer and reduce it to about once a month when the weather turns cooler. It is also good to flush out the excess salts from the media about once a month. Use pure water for this flushing.
I do change my formulations using a higher Nitrogen fertilizer (for leaf growth) from August to January and a lower Nitrogen, higher potassium fertilizer (to support flowering) from February through May. In general, do not fertilize in the wintertime. As you learn the needs of the kind of orchids that you grow you may want to fine tune your formula depending on your water quality and the potting media you use. The adage is “weakly, weekly”.
That said, it is best to fertilize about once a week or two in the spring and summer and reduce it to about once a month when the weather turns cooler. It is also good to flush out the excess salts from the media about once a month. Use pure water for this flushing.
What is the best way to learn about orchids?
Have a go! Everybody learns a little differently and it is best to take a broad approach. Acquire an orchid, and if you are new to orchids, try to get what is considered an “easy” orchid. One that is not too fussy and is relatively easy to rebloom. Take advantage of the resources available to you. Read books, either hard cover or eBooks. Check your library for orchid books. Go to an orchid show, they are held throughout the year. Consider joining the John Oxley District Orchid Society. Enjoy the satisfaction this hobby can bring.