Angraecum (an–GRAY-kum)
- In a greenhouse, shadecloth is required to reach about 10,750-21,500 lumens (1,000-2,000 foot-candles) depending on the plants. This would be a little brighter than phalaenopsis conditions, but shadier than for cattleya
- In the home, east, north, or west windows where they will get about 1-4 hours of direct morning or later afternoon sun are ideal.
LIGHT
Light needs are easy to fulfill for Angraecum orchids, as they can be grown similarly to Phalaenopsis. They can receive ambient light in a greenhouse or North window, with up to 4 hours of direct sun at the mostly AM and after 4PM. Most will thrive with two to three hours of direct sun a day, but shaded during mid-day.
Many types of Angraecum orchids will grow well under artificial light. Use lightbulbs/LEDs of your choice that are about 1-2 feet above the plant and emit >10,000 lumens per square yard/square meter. The lowest amount of lumens for growth is about 2000 lumens, though flowering may be poor.
TEMPERATURE
Temperature depends on the hybrid/species, but in general, Angraecum orchids are happy with with shirt sleeve conditions, 55F-72F (12.7C-22.2C) nights and 70F-85F (21.1C-29.4C) days. If growing indoors, there is no need to worry about temperature; room temperature all the time is fine. Fluctuating temperatures can cause bud drop on plants with buds ready to open. However, the plants themselves can tolerate a short temperature swing higher or lower by 10F (5.5C).
WATER
When thinking about water for epiphytes like Angraecum orchids, you must keep in mind that they like to have quick wet/dry cycles. Angraecum orchids like to go dry in between waterings but like to be immediately watered when their media hits dryness.
- If growing in a greenhouse, you can/should water daily regardless of whether it’s potted or mounted.
- Indoors, Angraecum orchids should be grown potted and, after watering from the top. Use shallow catch pans to allow the plants to sit in about ½” of their own flow-through for a day or two. Otherwise, indoor Angraecum orchids can be taken to the shower or sink and be watered, drip dry, then be placed back. The frequency will depend on how fast it takes for the media to dry in your conditions. Indoors, you can get away with watering less frequently by letting them sit in their own flow-through.
As with many house plants, always use lukewarm water when watering, as water temperature below 50F may injure plants. Plants should be thoroughly watered and not watered again until nearly dry. In the heat of summer in a dry climate, this may be every other day; in the winter in a cool northern greenhouse, it may be every 10 days. Water only in the morning so the leaves dry by night. Do not let water collect in the leaf axils or crown to avoid crown rot.
HUMIDITY
Humidity for Angraecum orchids is a bonus but is not necessary for growing these well.
- Indoors, as long as Angraecum orchids are well-watered and frequently watered, you do not need to worry about humidity. If you are not as frequent with waterings, then humidity should be brought up to 55%-85%. If you raise the humidity, the plant will be slightly more robust, but not incredibly so. Many homes run around 60% humidity in the Summer, but in the Winter, home humidity can drop below 50% which is not only too dry for your Angraecum, but for your family. Gravel trays help in providing localised increases in humidity in the home.
- In a greenhouse, air should always be moving around the plants to prevent fungal or bacterial disease, especially if high humidity or cool and wet conditions exist. Excellent air movement is enjoyed by orchids in general. When air temps cool, humidity rises, when the heaters come on, the humidity can drop quite low if greenhouse allowed to get too dry . Applying water under the benches and walks will help to raise humidity.
FERTILIZE
Fertilize and water regularly to produce strong plants. Use regular strength to ½ strength of a high nitrogen formulation (such as 30-10-10) while plants are in active growth, slowly tapering off as the season progresses. A blossom-booster formulation (such as 10-30-20) should be used as flower spikes are forming. Do not fertilize during the winter.
POTTING
Potting is best done in the spring, immediately after flowering, but can be done any time as long as the roots are kept as intact as possible. Angraecum orchid plants must be potted in a porous mix or mounted. Repotting is usually done every one to three years. Mature plants can grow in the same container until the potting medium starts to decompose, usually in two years. Root rot occurs if plants are left in a soggy medium. Seedlings usually grow fast enough to need repotting yearly and should be repotted in a fine-grade medium. Mature plants are potted in a medium-grade bark mix.
- Indoors, Angraecum orchids do best potted in a fine bark mix, regardless of size, and in a net/mesh pot that is slipped into a larger plastic (ideally clear plastic) or ceramic pot. The idea is that they can sit in about .5 inch (13 mm) of water, which wicks up into the media but allows the roots to breathe.
It is ideal, when repotting most Angraecum orchids, to pot them leaning forward at about 45 degrees or more. This will prevent the roots from “searching upwards”. To repot, trim soft, rotted roots and spread the remaining roots over a handful of medium in the bottom of a new pot. Fill the rest of the pot with medium, working it among the roots so that the junction of the roots and the stem is at the top of the medium.
OTHER
Some of these orchids require much higher light as they grow larger, such as Angraecum sesquipedale, which will start to look like (and will need the care of) a Vanda orchid. Note that the thinner-leafed species need obligatory humidity of greater than 60% and start to have the needs of Bulbophyllum. They will like it muggy and watered often.
Further information can be found on the Angraecum genus page.
Best orchid care practices are also provided for watering, repotting, and fertilizer types. There are also detailed discussions of growing orchids indoors, outdoors, or in greenhouses.
For more information on genus name changes, see Taxonomy.
