There is a common stereotype that orchids are elite plants, and that they are suited only for greenhouse growing – and that they are extremely difficult to grow even in a greenhouse. This stereotype is just the stereotype from XIX century, when most orchids were recently discovered and it was unknown – how to grow them, given the fact that they are mostly epiphytes and there were no techniques for orchid growing. Indeed there are difficult orchids – but their difficulty is in their natural habitat – for instance Dracula orchids are considered difficult for their specific temperature requirements. Terete-leaved Vanda is considered difficult for indoors for its extremely high light requirement, so there are difficult orchids indeed. But there are also a lot of so called easy orchids – these orchids have quite simple growth requirements and well suited for indoor cultivation. Their natural habitat growing conditions are similar with indoor conditions, so they do not need something different, or they are highly adaptive and can tolerate a wide range of growing conditions. Anyway, a common windowsill is a perfectly OK place to grow them, and that’s why they are called “easy orchids”.
In general, so called easy orchids have similar growth requirements. First – temperature. They are either of warm, hot or intermediate temperature groups (from 64 F to 90 F), and it is quite common temperature in any living room, or they have cool or cold dormancy in winter and can tolerate warmth at summer. Cool and Cold temperature groups are considered difficult to maintain, because required temperatures are not suited for year around human living, so you’ll need another place to grow them. Second – light requirements. Easy orchids do not demand high light levels, so a common windowsill of nearly any orientation is well suited for them. Or they should have dormancy at winter and do not demand high light levels at winter months, when sunlight is low. And also so called easy orchids are simply insensitive to day duration – so they do not need tricks as some unifoliate Cattleyas to bloom.
Third is air humidity. Easy orchids will tolerate dry air in common living room and do not need high air humidity and high air circulation (because high humidity in air without air movement is easiest way to rotting and fungal infections). That’s why some quite undemanding orchids are not considered easy just because they are suited predominantly for being cultivated, mounted on slabs. Mounted orchids usually demand higher air humidity to thrive. Another factor, differing easy and difficult orchids is watering regimen. For instance, Masdevallia orchids need golden mean, which is quite difficult to understand – both overwatering and insufficient watering can kill the plant quite rapidly. Easy orchids usually not very demanding – they can tolerate some dryness and overwatering for little periods of time (through dryness is better than overwatering, because overwatering can cause root rotting). There are main differences between easy and difficult orchids – easy orchids are more adaptable and forgiving for some mistakes, while difficult orchids do need quite strict growth requirements, which are usually not similar with indoor conditions, and they are difficult to maintain.
Phalaenopsis is considered to be one of the easiest orchid to grow. Indeed, Phalaenopsis hybrids, which are common at nearly ever shop, are quite simple to grow. They are adaptable, they have low light requirements, they are of warm and hot temperature group and easy bloomers. But some species Phalaenopsis orchids are not so easy to grow, and some considered particularly difficult. Oncidiums also quite simple orchids – they need higher light levels than Phalaenopsis, but they are also quite easy to grow and bloom, as well as Cambria hybrids (but not species Odontoglossum and Miltoniopsis orchids). Most modern Cattleya Alliance hybrids, for instance Potinara grexes and Brassolaeliocattleyas are also considered easy to grow and bloom – yes, they have high light requirements, but other growing conditions are quite easy to maintain. Ludisia orchid is one of the easiest orchids to grow – it can grow in so much differing conditions and even potted into common plants soil, so many do not believe that Ludisia is actually an orchid. Many Dendrobiums, including Dendrobium phalaenopsis species and hybrids are also considered easy to grow. Within Lady Slipper Orchids, the easiest group is warm spotted-leaved Paphiopedilums – this is Paphipedillum callosum group and Maudiae hybrids. Some terrestrial orchids – including Pleione, Bletilla and Calanthe are also extremely easy to grow, they can be even grown just as other common houseplants and some grow them in compost for common houseplants. Vanilla orchid is quite easy to grow – it is undemanding vine, and will grow without problems, but it is difficult to bloom. And not forget about some not well known orchids, which are also quite easy to grow – Maxillaria and Bifrenaria are quite simple to grow indoors, they are also quite decorative and nice and well suited for indoor cultivation on common windowsills.