Hothousing 3

It’s been nice to think about being in a winter garden in the middle of winter – bathed in sunshine today but a cool edge to the wind and more rain forecast later this week. So, on we go …

Last year was my first chance to visit the Princess of Wales Conservatory at Kew Gardens, opened by Princess Diana in 1987, although the glasshouse is actually named for another Princess of Wales, Augusta, mother of George III, who founded the Gardens in 1759.

With a floor space of 4,500 square metres, the glasshouse contains a whopping 10 different climatic zones and a huge variety of plants, from cacti and carnivorous plants to orchids and bromeliads. Each of the zone climates is maintained by a computer which adjusts heat, ventilation and humidity automatically. Hot-water pipes are used for heating.

The Princess of Wales Conservatory sits low in the landscape at Kew Gardens. Photo: Sandra Simpson

Architect Gordon Wilson designed the conservatory for maximum energy efficiency so much of it sits below ground to conserve heat and has a low volume compared to floor space so temperatures can be altered rapidly, while its specially designed stepped glass roof effectively collects solar energy. Rain water is collected and stored in tanks beneath the building before being used for irrigation.

Sir David Attenborough buried a time capsule in the foundation containing seeds of important food crops and several endangered species. It will be opened in 2085, when many of the plants it contains may be rare or extinct.

Kew’s giant (up to 2.8m wide) Victoria amazonica waterlilies are each year grown from seed. Photo: Sandra Simpson

The Conservatory is home to the world’s largest water lily (Victoria amazonica) and the smallest and rarest waterlily (Nymphaea thermarum). In 2014 someone decided to help themselves to one of the few examples Kew had of this tiny plant, extinct in its only known location in the wild, a thermal hot spring in Rwanda. Read a long, but very interesting piece, about this case and plant theft in general.

Hailing from tropical Africa is Strophanthus sarmentosus. The plant – which either grows as a tree or a vigorous, woody vine – has medicinal purposes but also produces poison for arrowheads. Photo: Sandra Simpson
Pachypodium lamerei is native to Madagascar. Despite its soft-petalled flowers, the trunk and branches are extremely thorny. This semi-deciduous tree is a member of the succulent family. Photo: Sandra Simpson
Thunbergia laurifolia, native to Asia, has been declared an invasive pest plant in Queensland where it does a bit too well, particularly in the state’s north, and concerns have also been raised about its spread in Hawaii. Photo: Sandra Simpson

My only problem with the glasshouse was getting out! My friends were patiently waiting for me to have my fill of taking photos and I decided it was time to get back to them. My first attempt at following the Exit signs took me round in a big circle so I asked an attendant (who, bless her, kept a straight face). I set off again and at a certain point made a left instead of a right and voila, there were some faces I recognised and a door to the outside world. Whew!

Hothousing 2

The Temperate House at Kew Gardens – once the world’s largest glasshouse and now the world’s largest Victorian greenhouse – re-opened last year (in time for my visit!) after 5 years of restoration. It is home to more than 10,000 plants of 1500 species.

The main part of the Temperate House, Kew Gardens in August 2018 (the drought would break during our visit, hence the moody sky but the still-brown grass). Photo: Sandra Simpson

Designed by Decimus Burton, the master of glass and iron who also designed the Palm House, the Temperate House is 4880 square metres, twice the size of the Palm House. It was built between 1859 and 1898.

Burton designed the interior so that plants could be grouped by geographical region and this planting style is still used today. Many of the plants, which need conditions above 10°C to survive, are familiar as New Zealand’s native plants mostly fall into that category.

The interior of the main Temperate House. Photo: Sandra Simpson

Kew is one of the world’s leading conservation organisations and ‘home base’ is a chance to share some of the successes and challenges the world’s plants face.

Cylindrocline lorencei (Mauritius tree daisy) “must be one of the most extreme cases of recovering a species from the brink of extinction”, says Carlos Magdalena, a Kew scientist. “It was not achieved from the last plant, nor the last seeds, but from the last living cells of the organism on earth.”

The seed which had been stored could not be germinated and the species was only saved by staff at Brest Botanic Gardens in France who successfully carried out in vitro culture of a viable part of a seed embryo. The shrubs are now flourishing at Brest and Kew and it’s hoped to re-establish a population in its native habitat. Read more here.

Cylindrocline lorencei in the Temperate House at Kew. Photo: Sandra Simpson

The friends who took us to Kew decided that day to sign up as Friends and have been back several times since for special events and just to wander. I well remember what a treat it was having Kew Gardens within striking distance of home with something different to see on every visit.

Sparmannia africana (African hemp or house lime) is native to South Africa and a member of the mallow family. Read more here. Photo: Sandra Simpson
Hedychium coccineum (scarlet ginger lily) is native to southern China, the Himalayas, India and Indochina. Read more about the Hedychium family. Photo: Sandra Simpson
The long needles of Pinus roxburghii (chir pine) help it survive fires, common in its native habitat of the Himalayan foothills, by drawing the flames away from the stem. Photo: Sandra Simpson
As part of the refit, viewing galleries have opened right around the Temperate House ceiling area, accessed by ornate spiral staircases. Photo: Sandra Simpson

Plant stories: Japanese pagoda tree

Despite the sometimes heavy rain we enjoyed our recent visit to Royal Botanic Gardens Kew in London very much – the Temperate House has been re-opened; our friends took us to the remarkable paintings of Marianne North (1830-90; no photos allowed so click on the link to see the amazing interior of the gallery); the Princess of Wales Conservatory … and right beside The Hive art installation was a tree covered in a mass of fine white blossoms.

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Japanese pagoda tree at Kew. Photo: Sandra Simpson

Turns out this Japanese pagoda tree is one of the few remaining trees that was planted in the original 9-acre botanic gardens in about 1760! This tree is one of five imported for Kew by James Gordon (1708-80), a famous nurseryman of the time, and who introduced the tree to the UK in 1753, bringing it from Japan. He was also the first person to successfully germinate the seeds of the maidenhair tree or Ginkgo biloba from China and the specimen he gave Kew is another heritage tree still growing there.

Actually native to China and Korea, the Japanese pagoda tree was often seen planted in the grounds of Buddhist temples in Japan and collected by English botanists there which is how it got its common name. The Kew signboard says it’s often grown as ornamental, thanks to those masses of delicate flowers, but it is also used for timber, furniture, medicine and food. A yellow dye can be extracted from the seedpods and is commonly used for silks and batik.

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Daresay I’ll need some support when I’m 258 years old! Photo: Sandra Simpson

The Latin name of the tree – originally Sophora japonica – changed in 2006 to Styphnolobium japonicum based on information collected from DNA sequences by Kew scientists.

I’m not sure if The Hive was placed near this tree deliberately, but the flowers are certainly a magnet for bees. We could hear the buzz, even on a wet day.

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The tree flowers in late summer making it valuable to bees. Photo: Sandra Simpson

The Hive is a fascinating place, an artwork hooked up to a real beehive in the grounds to create an immersive experience for visitors.

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Wolfgang Buttress originally created The Hive for the UK Pavilion at the 2015 Milan Expo.
It’s 17m tall and constructed from 170,000 aluminium parts and 1,000 LED lights, and can be entered on two levels. Photo: Sandra Simpson


Titan arum prepares to bloom

Nick Lloyd, editor of The NZ Internet Orchid Review, reports that a specimen of Amorphophallus titanum (titan arum) is in bud at the Wintergardens in Auckland Domain – the flowers can grow to more than 3m high and 3m in circumference.

“This will be flowering at some stage in December and is the first flowering for this species in New Zealand,” he says.


The titan arum in flower. Photo: US Botanic Gardens via Wikimedia Commons

Read more about the plant, also known as the corpse flower because of its scent, on the Kew Gardens website. It is native to Sumatra and the Bonn Botanic Garden website reports that only about 70 plants have flowered “in captivity” since the titan arum was discovered in 1878.

A plant bloomed at the US Botanic Garden Conservatory in Washington DC in July, the first time it had flowered even though the plant was nearly 10 years old. The website records that the public display began on July 11; the titan began to open the evening of July 21; started to close the evening of July 22; and collapsed the evening of July 24.

“The ephemeral nature of the bloom, coupled with its unpredictible flowering schedule, attracted more than 130,000 people to see the plant in person, and more than 650,000 views to the live webstream,” the website says.

Pollen was collected from the male flower and sent to the University of California in Santa Barbara where a female flower was ready to open. This cross-continent pollination, if successful, may produce seeds-corms-plants. The tubers can grow to weigh up to 75kg!

According to Wikipedia, the name “titan arum” was invented by Sir David Attenborough while filming The Private Life of Plants, in which the flowering and pollination of the plant were filmed for the first time. “Sir David felt that constantly referring to the plant as Amorphophallus on a popular TV documentary would be inappropriate.”

A related, but smaller, arum, Amorphophallus konjac (devil’s tongue arum), flowered in the Wintergardens last year.

Wednesday digest

The Hampton Court Flower Show has opened today – some unusual garden designs, including one that references the disease killing ash trees in Britian.

Best in show has a giant green plastic detergent bottle pouring water over an arc of plastic. Here’s a picture gallery of the gold medal gardens, hover your mouse over the number at the top to pick and choose if you don’t want to run through them all.

Here’s a writer who thinks “guerilla gardeners” have gone a step too far in trying to “farmify” cities. It makes interesting reading.

The Royal Botanic Gardens at Kew is celebrating its “surprising” edible plants with an IncredEdibles Festival that runs until September 1. Meanwhile, the gorgeous, and historic, Temperate House is closing on August 4 for a five-year restoration. Read more about that here.

Monday digest

Hope you’ve all caught up with the fact that The Kingdom of Plants with David Attenborough is showing on TV One on Tuesdays at 8.30pm. Filmed at Kew Gardens,  last week’s first episode dealt with wet zone plants. If you missed it, the episode is available from TVNZ on demand.

Here is a short introduction to the series.

While we’re on the subject of Kew visit the Fungarium at Kew in this video (5min35). Why are fungi important? Watch and learn – they are essential to plant life and so all life on this planet.

Another Behind the Scenes at Kew video, this one on the Millennium Seed Bank (5min17). Did you know that the only time a plant can move is when it’s a seed?

Dubai Miracle Garden is the world’s largest natural flower garden (although judging by the photos the meaning of “natural” in Dubai may be a bit different).

And check out this stunning gallery of photos from the International Garden Photographer of the year 2013. The winner is Dennis Frates for a shot taken in Crater Lake National Park in Oregon.