There are lots of orchids – thousands and thousands of species and ever more hybrids. And it is quite natural that there are a lot of orchid growing techniques for different orchid species and hybrids, fitting their growing requirements. There is no universal growing technique, and even more – some growing technique, which is fairly good for one species, may be deadly for others. For instance, Spiranthes orchids will die if you mount them on slabs, and epiphytic orchids will rot being potted into soil mixture. So, there is the question – how to grow orchids best and where do orchids grow best. Orchids can be separated into large groups, according to their ecological characteristics into epiphytes (actually this is the largest group), which grow on other plants – trees, shrubs and even cacti (as Zelencoa onusta orchid does) such as Cattleyas, Vandas, Phalaenopsis, many Oncidiums, and others; lithophytes, which grow on rocks and stones such as Bifrenaria orchids, some Laelia orchids, terrestrials, which grow in soil such as Jewel Orchids, Pleione, Calanthe and others, and there also so called aqueous orchids (actually swamp orchids) such as Spiranthe, which can grow even submerged underwater in aquaria! There is also one very interesting group of orchids – myco-heteotrophs, which lack photosynthetic pigment and actually parasites on microscopic fungi, but there is no growing technique for them, so they are impossible to grow in artificial culture. But all other groups require different growing techniques.
Historically, the first technique of orchid growing was growing them potted. When tropical rainforests were newly discovered and there wasn’t any information about how to grow epiphytes, first botanical gardens tried to cultivate orchids potted in common soil, but they failed with few exceptions. Only terrestrial orchids such as Calanthe could grow in common soil, epiphytic orchid’s roots require oxygen, so they are simply rotted and died. And there is a myth about orchids – that they are extremely hard to grow even in greenhouse. Then botanists have researched epiphytic lifestyle and concluded, that soil is not well suited for epiphytic orchids cultivation, and started to experiment with different growing media, including osmunda (which once was extremely popular, until osmunda fern became endangered species) and finally bark, sphagnum, charcoal, ceramic particles, cocoa chips and even some inorganic such as epiweb and so on. So, how to grow potted orchids – you just need to know, which species you grow, if it is terrestrial – pot it into mixture for terrestrial orchids or even soil, just water and fertilize it – it require the same care as other houseplants. If you possess epiphytic or lithophytic one – you should pot it into proper mixture such as bark or lava rocks (if you have lithophyte), and then try not to overwater it – and if you grow them potted in not transparent pot and do not actually see roots it is quite simple. While potting orchids in bark, try not to break the roots. Some orchids such as Stanhopea and Dracula do best potted into hanging baskets with lots of holes in bottom and on lateral sides. This is not only for roots aeration, but also to allow their flowers bloom correctly – they bloom upside-down and that’s why need to be potted in such way. If you are still wandering how to look after potted orchids – regularly water and fertilize the plants but not overwater, because potted orchids are extremely prone to root rotting.
The other (and the most suitable for most epiphytic orchids) growing technique is mounting. Mounting orchids on slabs just mimics their natural way of growing. The roots stay open, well aerated and clearly visible, so it is nearly impossible to overwater a mounted orchid, especially if you choose proper orchid mounting media. You can use either wooden slab, bark or cork, treefern, and there are ceramic slabs with or without reservoirs for water to evaporate and cool the slab with orchid, there are also epiweb slabs. Some species require a moss interlayer between slab and orchid roots, some don’t. Another advantage of orchid mounting is doubtless decorative qualities of mounted orchids. They are growing in their natural way and you can see the beauty of rainforests indoors. But the disadvantage is that they require more air humidity, and that mounting is not very well suited for large and giant orchids (for obvious reasons), mounting is the best way to care for orchids which are epiphytic and medium to miniature sized.
Another way to grow orchids is to grow them bare-rooted. Vanda is an excellent example of orchid which can grow bare-rooted in a hanging basket. Such epiphytes with so thick velamen layer like Vanda orchids need their roots to dry very quickly. So, the only way of successful Vanda growing is to allow their roots to dry fast, because potted Vanda usually loses its roots quite quickly because of overwatering and root rotting. Some orchid growers keep them bare-rooted in hanging baskets, allowing their roots to droop freely, but others place them in glass bowls for aesthetic reasons. Besides aesthetics, keeping orchids in a glass bowel enhances the air humidity around an orchid, so planting orchids in glass bowls is quite dangerous, because humid, stagnant air is not very good for orchids, so you may need to provide air movement.
And if you want, you can also grow you orchid in a terrarium. If you decided planting orchids in terrariums, you should know that you have to equip terrarium with a bright light source sufficient for species you grow, and equip it with a fan to provide sufficient air movement – high humidity without appropriate air movement is a very fast way to kill orchids. So, where do orchids grow best – they grow best in nature, but if you can provide them with right growing conditions and somehow mimic their natural habitat, they will grow and bloom regularly.