You may have noticed that we have had a fantastic array of lovely species flowering this spring and we are still in the main flowering period for the orchid collection – A question we are often asked is ‘why do so many species flower in the spring?’
Many of the orchid habitats we have visited (especially the Himalayas, South East Asia, Brazil and Central America) have a strongly seasonal climate with the general rule for tropical forests, away from the equator, being cooler dryer winters and warmer wetter summers. In this seasonal climate the best time for orchids to be putting resources into developing seed and seed pods is during the wet warm summers, and so the best time to flower is just before the warm wet summer, at the end of the dry season – so spring.
One species that flowers just before the wet season is this gorgeous Dendrobium that we have seen growing abundantly in southern Laos.
Dendrobium chrysotoxum is native to seasonally dry forest monsoon forests and we found it in several locations at around 1000m around Paksong on the Bolaven Plateau. Plants were mostly growing on the trunk and lower branches of large trees in good light as shown on the photo below.
In cultivation we reflect the natural habitat by growing plants warm and wet in the summer in Warm Asia but give a cooler and much dryer winter in the top of Cool Americas. We find that baskets are ideal for this rewarding species.
Our greenhouse is once again full of the pungent spicy aroma of this wonderful orchid that flowers in profusion from leafless bulbs every spring.
Lycaste aromatica is native to Mexico and Central America where it grows as an epiphyte of lithophyte in semi-deciduous forest. It uses its powerful scent to attract euglossine bees (perfume gathering bees) and in common with many plants adopting this strategy has fairly short lived flowers (a couple of weeks).
The native habitat experiences a marked dry season and so the species drops all its leaves in November and remains leafless until April or May. We reduce watering to almost none while there are no leaves but in the summer once growth is underway we water heavily to support the rapidly growing lush leaves.
It suits our temperatures in Warm Americas with a winter minimum of 15C
One of the smallest orchids flowering this week is this Asian miniature. Minimiflora means ‘tiny flowered’ and this species lives up to its name. The species is found in Thailand, Malaysia and the Philippines and grows as an epiphyte (on trees) or a lithophyte (on rocks) in hot lowland rainforest.
The long lasting tiny flowers are about 1mm across with many produced in succession on a pendulous spikes up to 10cm long. The span across the leaves is just 5cm but our plant seems determined to become a specimen against the odds and is developing additional growths and so eventually for a clump. The plant produces lots of roots when grown mounted and we hang it high in our Warm Asia section where it gets a daily watering from the hose.
We have another of the dramatic dendrobiums in flower this week with Dendrobium farmeri. This species is similar to Dendrobium thyrsiflorum but with pinky petals and a yellow lip rather than white petals and a yellow lip. The flowers are often a little more closed than Dendrobium thyrsiflorum (see below for comparison)
Dendrobium farmeri is found from Sikkim to South East Asia and we have seen it growing at an altitude of 500m on large boulders in West Bengal near Kalimpong in full sun where it would experience wet summers and much dryer cooler winters.
We grow the several clones of the species in the same conditions as Dendrobium thyrsiflorum in baskets in our Warm Asia section.