7 August 2013

UK's first Wollemi pines from seed

In 2011 seed I collected from Wollemi pines growing at Kew were germinated in our Arboretum nursery, producing dozens of seedlings. Now, two years, on we have lots of new young plants to add to our collections

By Tony Hall

Wollemi pines, Wakehurst

"The botanical find of the century" 

In 1994 David Noble, a field officer for the National Parks and Wildlife Service Australia in the Blue Mountains area of Australia, discovered a small group of very large trees in a remote canyon of the Wollemi National Park that were until then only known from fossil records. The new species was named Wollemia nobilis, the Wollemi pine. 

Collecting the seeds 

In September 1997 two plants were presented by the Hon. Mrs Pam Allan, New South Wales Minister for the Environment, to the then Director of Kew, Professor Sir Ghillean Prance. A further batch was sent to Kew in 2005 for hardiness trials and subsequently planted in the arboretum in 2008. Back in 2010 I noticed some of the Wollemi pines growing in the Arboretum were producing seed-bearing cones. I had meant to collect some of the seed in that year but missed the opportunity. Marking it in my diary for the following year, I managed to collect some seed in 2011. (A short article detailing the collection and germination of the seed was published in the Kew Scientist October 2011 issue.) 

Sampling cones for seed 

25 cones were produced on one individual in that year and six were collected and sampled for seed. The cones had an average of 187 seeds in them although seed viability was generally low at just over 10%. 

Sowing the seed 

The seeds were sown in batches from each cone in the Arboretum nursery, which is where all of Kew's woody temperate propagation is carried out, by my nursery manager Andrew Luke. Germination of the Wollemi pine seed started at 42 days. We didn't sow all of the seed: the bulk of it was sent to the Millennium Seed Bank for storing. 

Kew's original specimens 

Some of the original Wollemi pines planted in the gardens are doing really well, growing approx 1 metre per year, with a small group of five all around 6 metres tall, the tallest being 6.3 metres. These original trees were part of hardiness trials carried out at Kew between 2005 and 2007, with the trees being planted out in the Arboretum after the trials had finished. The ones being planted in lower pH areas are doing the best.