The results from these trials will help shape which species of trees are best suited to make up forests of the future.
Sarah Eberle's RHS Chelsea Flower Show The Resilience Garden, inspired by gardener William Robinson, whose Gravetye Manor estate is now managed by the Forestry Commission, features monkey puzzle, ginkgo and Japanese cedar - identified as a potential source of fast-growing timber.
The Resilience Garden will be built and planted by Crocus at this year's Chelsea Flower Show.
There are also show gardens from Wedgwood, Welcome to Yorkshire, Trailfinders, Savills, Morgan Stanley, Ikea, Dubai and M&G.
Two gardens look to have been moved up from the smaller Space to Grow area to become large show gardens - Greenfingers and Warner Edwards.
Meanwhile, Thorncroft Clematis' new 'Meghan' clematis is named in celebration of the royal wedding of Meghan Markle and Prince Harry.
The purply-red summer flowers are produced in abundance May-June and again from late July-September, on the current season's growth.
At the Chelsea press launch at The Dorchester in London, the RHS said it has had to ban oaks for 2019's Chelsea because the Royal Hospital show grounds are now infested with the pest. This comes after a finding of Oak Processionary Moth at Chelsea in May 2018 that had to be eradicated in the week before the show, something that went unreported until October 2018. Defra banned movement of oaks into infected zones, which are currently in London and surrounding areas, in August 2018.
RHS director general Sue Biggs highlighted October 2018's Ornamental Round Table-commissioned report that found that the industry was worth £24bn.
Also in October 2018, the RHS told exhibitors they needed to have trees brought into the UK three months before the show. Imported tender plants are to be inspected by APHA inspectors. Biggs said 90% of garden plants at Chelsea were supplied by British nurseries. In late 2017, the RHS banned nine Xylella-risk plants from the show, including lavender and olive, unless they are grown in the UK for 12 months before the event.
Radio 2's Jeremy Vine interviewed 2018's Chelsea garden feature designer Matt Keightley about his RHS Feel Good garden, which was donated to Camden and Islington mental health trust after 39 out of 54 UK mental health trusts applied to have it installed aftet the show.
The two star turns at Chelsea 2019 will be the Duchess of Sussex/White-Davies garden feature and John Everiss' D-Day anniversary garden. Adam White and Andree Davies spoke about the Duchess's contribution to the garden at the press launch.
There are 28 gardens altogether. In Space to Grow there are seven first timers out of nine.
There will be 80 nurseries. David Austin Roses will commemorate the nursery's late founder. Andy's Air Plants and Bonsai Guys are new. Medwyn of Anglesey is back. Lime Cross, New Forest Hostas, William's Cactus, National Allium Collection, Grafton Nurseries and Salutation Garden will exhibit.
New plants include a Clematis 'Meghan' from Thorncroft, a new begonia, Streptocarpus Lemon Sorbet from Dibley's and Rosa 'Chawton House' from Harkness.