Dendrobium is also known as the Spray Orchid, and together with Phalaenopsis it is one of the most popular orchids in the US. They grow upright and can develop a very long cane, between 1 and 4 foot long. This "cane" is a pseudobulb and will store water so that the orchid can survive dry spells. Each cane will develop one or more sprays of beautiful blooms from white to pink. They are easy to care for but desire more attention than phalaenopsis. With regular watering and a short rest period their flowers will return year after year.

You can find Dendrobium orchids at your local flower store, garden or home center. The price range, mostly depending on size, is between $8 and $30. Some rare or award winning plants might cost between $50 and $100. When you buy your plant, make sure it is in good condition. The leafs should be of a medium green and the pseudobulbs should be firm.

Light
Dendrobium likes bright light and limited direct sun. A west or east facing window with direct sun for several hours is ok. A south facing window with might work well in the northern part of the US.
I use a light meter to measure the light intensity. For Dendrobium orchids a light level between 15,000 and 25,000 Lux or 1,500 and 2,500 Footcandle is recommended.

Temperature
Most Dendrobiums do well in normal indoor temperatures. They like 80 to 90 F during the day and 60 to 65 F during the night. What they do not like is too much dry heat, for example near a radiant heater or in a south window. Also avoid cold air fom AC units or ducts. In colder climates like Minnesota there is a risk from cold air intrusion through window cracks or from the cold glass. Check frequently and use a window insulation kit if necessary.

Water
The potting media should not dry out while a dendrobium is growing. Once the growth is finished, let the potting medium completely dry out befor the next watering. If you look at the media you will find that it is mostly made from chuncks of barch, vulcanic rock and coconut husks. All these materials allow a lot of air to come to the orchid roots. But most of these materials do not absorb and store a lot of water. The best watering method I have found is to submerge the orchid pot in a bowl of water for 15 minutes and then to take it out and let the excess water run off. Watering frequency depends on the temperature and humidity in your house, but once or twice a week should be suffcient. In many loactions tap water contains a lot of minerals and is not recommended for orchid watering. Use clean rain water, filtered drinking water or distilled water instead. Also be careful if you have a house water softening unit installed, some of them put a lot of sodium in the water and orchids do not like that.
You can use a "TDS meter" to measure the mineral content of your water. The reading for water without fertilizer should be below 100 ppm.

Humidity
The best humidity range for Dendrobium is between 50 and 60 % relative humidity, but with regular watering they will tolerate lower humidity. To create a better microclimate you can also place trays with moistened pebbles around your plants. They also like to be sprayed with destilled water on a daily basis, but make sure that there is no water in the center of the leafs, since that may promote rot.

Fertilizer
Since the potting media contains little nutrients, a weekly fertilizing with dilluted fertilizer is recommended. In most cases a balanced 10-10-10 or 12-12-12 fertilizer at one quarter to one half of the manufacturers recommended strength works well. I usually fertilize for 3 or 4 weeks in a row and then do one submerged watering with clean water without fertilizer. This will flush excess minerals and nutrients away and will prevent an unhealthy build-up of excess nutrients.

Potting
You should repot your Spray Orchid every two or three years, before the potting media breaks down or accumulates too much minerals. Use a pot on the rather small sie for the size of your plant. The best time to do this is right after the flowering. More details in the potting section.