Dracula roezlii ('San Francisco' x 'Carmel')
Unlike more popular orchids, Dracula plants are adapted to very high humidity and frequent mist and rain, and thus don’t store away water in succulent leaves or bulbs, but are found happily growing in patches of pillowy green moss. They are still epiphytes, however, and by nature of growing on trees are unable to handle their roots staying potted in soil or in a boggy environment; and due to their habitats staying humid, have trouble flowering in dry air, so it’s best to grow them in a terrarium or some type of greenhouse where the flowers can open.
Fundamentally:
Keep Dracula orchids are room temperature (60 – 85 F, with notably cooler temps at night.)
Require high humidity for the flowers to develop and open well (at least 70% relative humidity during the day, ideally higher at night), but can handle growing in 50 % relative humidity; ideally in places where moss and ferns grow well.
Don’t keep it boggy and wet, but don’t let it stay dry like other orchids like to; it should grow like a sponge that dries out regularly but is still springy.
If grown outdoors, don't give it too much sun; it grows under the canopy and in shady sun (~ 1000 – 1500 foot-candles)
Black leaf tips : too much water Brown leaf tips : water that is too high in dissolved solids/salts
Repot every two or three years to remove old potting mix before it decomposes
Temperature
Most Dracula orchids are found between 800 and 2700 m (2400-8900 ft) elevation above sea level, and thus are in cooler locations than what you expect in the tropics; since they are found close to the equator, though, this means they don’t experience seasonal temperature changes, and thus it’s generally best to keep them at room temperature, between 60 and 80 F. Although, they can handle down to 50 F with little trouble for a few days; but above 85 F, many Dracula can start to suffer from heat stress if exposed to high temperatures for prolonged periods, especially if they are kept above 70 F at night. In these cases, we’ve learned that naturally heat waves are accompanied by droughts, so only lightly water if you are having heat trouble, and lessening sun/light exposure during hot days helps reduce heat stress too.
Humidity
These orchids are usually found in very misty regions, where the clouds or fog roll through mountains. They are thus accustomed to blooming when it’s very humid and under the same conditions certain variety of mushrooms sprout, which might be under warm or cool conditions. Since the flowers themselves are papery thin and often fuzzy, they are best presented in humid conditions.
Water
When it rains in the forest, the whole plant will usually get wet and it lasts for a few hours; since Draculas don’t grow in the soil, that rainwater is all they’ll get, so they are used to frequent cycles of drenching followed by breezes drying out their roots. Thus, we find planting a Dracula in a basket is often the best way to grow them, especially with something that holds moisture, like sphagnum moss or some fine fiber/orchid mix. The baskets expose the potting mix to more air than normal in order to dry out faster than in a closed pot, and the holes also allow the flower stems to descend out the base and orient themselves downward
The basic rule of thumb is that a Dracula should be watered the day before it fully dries out; when planted in moss, this ideal point is when the moss is slightly lighter, somewhat dry and still springy. In other potting materials, it can be a little harder to tell, but one way to know is to track the weight of the plant after being thoroughly soaked and see when the weight becomes constant, and then counting how many days it took and subtract one; or you can use a toothpick or popsicle stick to check to see how much water is still in the potting mix like an oil dipstick in a car by how much the wood darkens. Generally (this is subject to many variables), this means that in a greenhouse it takes weekly waterings, and in a house it’s every 3 days or so. Having said this, nature is never perfect, so orchids have adapted to droughts and rainy seasons, and if you’re a little late every so often, it’s better than staying a little too wet.
The water quality is another aspect that can be important, mostly if there’s a problem. Since Draculas are used to only rainwater, they as sensitive to fertilizer and water with high amounts of dissolved solids. You would see this if the leaf tips start to turn black as the solids build up where there’s less vein pressure and slowly stain the leaves. If you have a water softener, you need to make sure you’re not using water with added salt (you’ll know if you have one), and with fertilizer make sure you’re only using about ¼ teaspoon per gallon, as well as rinsing through to leave behind less sediment. If you have trouble with fertilizer causing root or leaf damage, you can also wait ½ hour and water the plant again with clean water; the roots will have absorbed all they could in that time and the clean water will rinse off the excess that can cause problems. We generally fertilize once a month or so.
Light
These grow among mosses and under the cover of shade, much like Bram Stoker’s character, so dappled or indirect light is best, approximately 1200 foot-candles, or about what many begonias or Paphiopedilums do best in.
For more information visit this Dracula orchid care guide