Vanda denisoniana – 365 days of orchids – day 757

We have noticed that several of our orchids are flowering at different times of the year in 2019 compared to previous years. This may be linked to our exceptionally warm summer last year or the very mild winter we have experienced so far.

Vanda denisoniana usually flowers around Easter but has just opened its first ever flowers in Janurary.

The plants were grown in our school laboratory from seed collected from cultivated plants in Luang Prabang, Laos, in 2006. We found plants growing in a back street in this wonderful city (a world heritage site) and were struck by the beauty of these subtle flowers.

 The parent plant in Luang Prabang.

The plants had ripe seed and a small quantity collected was sown back at school in 2007. The majority of the seedlings were returned to Laos when we visited and helped Souk and Eddie set up their laboratory in Paksong in 2011 but a few were kept to grow a permanent seed source at Writhlington.

The plants have grown well but slowly and we were sure that they had reached flowering size and so have been moving them around in our Warm Asia section to find the perfect spot. The plant living near the door on the south side of the greenhouse responded by throwing out its first spike this spring and the flowers opened this week.

We grow the plants in baskets that allow their extensive roots to hang freely in the air. We spray plants daily throughout the year.

The species is found in primary forest from 450-1200m from Southern China, Burma, Thailand, Vietnam and Laos. It is probable that the plants in Luang Prabang originate from the still heavily forested North Eastern Laos. The flowers have the added benefit of being beautifully fragrant in the evening. More seedlings will hopefully be available from these plants from about 2019.


Dendrobium speciosum – 365 days of orchids – day 756

Our team in ‘Cool Asia’ are really enjoying being surrounded by the Dendrobium speciosum this week. This magnificent orchid is native to Australia.


Its aboriginal name is “Tar-Beri” and it is also known as the “Rock Lily”. When in flower it is one of our largest orchids measuring nearly 2m across with many hundred lovely fragrant flowers each about 2cm across. It is one of those orchids that stops you in your tracks and must be a fantastic sight in the wild where it grows on rocks in open forest in New South Wales and Victoria.

Across its range this species shows considerable variation in the size and colour of flowers. We have the large yellow clone as well as two white flowered clones, one large growing and one much smaller and a smaller growing creamy clone.


The pseudobulbs of this species are huge – 50cm high and with a diameter of 5cm at the base on the larger clones – and they repeat flower over a few years which helps to provide the fantastic display in a year when it decides to flower profusely.

Interestingly the larger clones didn’t flower at all last year and they seem to enjoy a two year growing cycle. We grow plant in baskets where they can have copious water in the summer but always good drainage. We use our usual bark without moss although baskets become packed with roots over time. All our plants hang up in Cool Asia with a minimum winter temperature of 10C and the flowers will last a good time and may still be out for the show season.


Dendrobium malvicolor – 365 days of orchids – day 755

This delightful small growing species is endemic to Sumatra where it grows from 1550 to 3050m. This is the first flowering of a seedling plant with small dark pseudobulbs which are thin at the base and thicker near the end where they flower.

We grow the species in our Warm Asia section but in light of the high altitude it would be happy a little cooler.

We have nearly fifty dendrobium species in our collection and this wonderful diverse genus includes many of our most flamboyant orchids as well as delicate species like this one. Walking around the greenhouses today we identified several dendrobiums in bud that will flower for our many shows this spring so look out for some lovely species over the next few weeks.

We also have a number of dendrobium species seedlings in our lab and this Friday will be sowing several new species as part of our work with a project we are keen to support in Myanmar. Full details later in the week.



Oncidium maculatum – 365 days of orchids – day 754

This lovely Oncidium is new to 365 days as the plant we have had for many years was divided a couple of years ago and is now back to flowering size.

Oncidium maculatum is native to Mexico and Central America where it grows in wet forests from 1000 to 2000m altitude. This habitat suggests it would be happy in either our Warm Americas or our Cool Americas sections and we have grown it in both although we have found that plants do best in Warm Americas where we keep plants wet and in relatively bright light which encourages the large pseudobulbs that flower well.

We grow the species successfully both in pots and in baskets.

The flowers are long lasting and large compared to most Oncidiums making this a really attractive species and one we have used in breeding.