Growing Warm Orchids from the Americas
In this article I will look at the iconic orchids native to warm lowland forests in South and Central America. In expeditions to the Americas we have had a chance to explore warm lowland forests as well as cool montane forests. In particular we have explored the lowland forests of Belize and Guatemala as well as low elevations in the Mata Atlantica, Brazil.
Cattleya intermedia, native to coastal lowland forests of Brazil
In Guatemala we worked alongside the Private Natural Reserves of Guatemala to research the orchid species present in a new reserve surrounding Laguna Yaxha in the north east of the country. The photo shows our expedition team on the edge of Laguna Yaxha with the boat we used to cross to the explore the forest on the far bank. Together we produced a field guide to orchids of the new reserve, a challenge and a treat.
This area was once the centre of the Mayan Civilization which collapsed around 900AD and the lowland forest is full of Mayan Pyramids, many unexcavated, stone remains, and littered with pottery fragments.
Compared to the wet, evergreen mossy forests we had experienced in the cool montane forests of Brazil and Costa Rica the forest we found in Guatemala was open, bright, hot and comparatively dry. Epiphytes are were much more sparse this made the orchids present much easier to spot and identify. We found July day time temperatures in the 30s and night time temperatures in the high 20s. Climate data shows that the mean day temperature hovers at around 30C from March to October and is a few degrees cooler from November to February. Mean minimum temperatures vary from around 20C in the winter and 23 in the summer. Although the data shows the main rainfall period is from June to october with rainfall on twenty days each month we found that the sharp showers experienced most days were short lived and left a forests dry soon afterwards. (Yes those are hats in the photo, we have balanced our hats on sticks while we look upwards for orchids with binoculars)
We identified a number of charismatic species including abundant Prosthechea cochleata and radiata, Brassavola cuculata, Guarianthe bowringiana and the ever present Myrmecophila tibicinis.
Photo – Prosthechea radiata in trees amongst Mayan Pyramids.
We were intrigued to understand how orchids could be so successful in such a challenging environment and identified a number of clues in the orchids we observed.
The first clue is the extensive root network developed by the orchids. One relatively small Prosthechea cochleata plant in flower had roots extending over 2m along its branch. This means that the plant can absorb considerable water from the heavy showers we experienced. A second observation was that many plants appeared to be of similar ages. A large number of Prosthechea radiata plants were seen all at first flowering with a second group perhaps five years older. We postulate that most years are not conducive to seedling survival but in the climatically good years a large number of seedlings flourish and establish themselves for long lives with little competition.
Photo below – Prosthechea cochleata on a cliff edge overlooking laguna Yaxha.
These observations support our experience in cultivation where a number of the species observed in this fairly dry and harsh environment actually prefer to grow wetter and cooler than in their native Guatemala.
In Belize we observed a number of the same species flourishing in lowland forest and mangrove along the Belize River at 1m above sea level. The forest had very similar conditions to that in belize apart from the boggy ground (with tapir footprints) with Brassavola nodosa flourishing in exposed positions alongside Myrmecophylla tibicinis.
Photo – Mymecophylla tibicinis growing together beside Belize River.
On higher ground we found denser forest supporting a wide range of species including Epidendrum stamfordianum, Encyclia bractescens and Psygmorchis pusilla.
Psygmorchis pusilla is a wonderful; miniature orchid that we also spotted in Guatemala and often grows as a twig epiphyte, flowering quickly and setting seed in a very temporary microhabitat.
Photo – Psygmorchis pusilla in Belize
A key observation from the forests in Belize was the importance of microhabitat just as we have seen in all of our field studies. An excellent example is the hot growing Belize form of Pleurothallis grobyi which we only found growing amongst moss on fallen wood in deep shade.
Photo – Pleurothallis grobyi in moss on fallen wood in lowland forest Belize
Similar observations were made in Brazil when visiting lower altitude orchid habitats nearer the coast than the cool cloud forests around Macae de Cima.
Leptotes bicolor is a species we have had since 1994 and it was fascinating to see it growing on a moss covered south facing cliff at 800m altitude where it would never experience direct sunlight.
So let’s have a look at how we manage our cultivation regime for the warm growing species of the Americas at Isle of Portland Orchids. Our key themes are bright, warm and airy just like the forests we have visited. We provide these conditions in three different growing areas. Indoors as house plants, as orchids growing in the roof of our Cloud Forest Greenhouse, and in our IKEA growing cabinets indoors.
Warm orchids as house plants.
The warm dryish forest we explored in the Americas are not unlike the conditions we find in the well lit areas of our house - near South facing windows.
A good example is Sobralia macrantha that we grow in our bedroom near to our velux balcony. We water the plant every 3 days (and feed during the growing season at 500 μS/cm) and it needs very little other attention - it does grow towards the light, perhaps it likes the sea view.