Palmstead Nurseries and Deepdale Trees are supplying 270 trees, 2,000 shrubs, hedging plants and climbers, 22,000 perennials, ferns and grasses and 64,000 bulbs between them for the proposed park bridge over the River Thames in London. Planting was due to start on the bridge in November 2017, with the garden open to the public in summer 2018.
But the project has been beset by protests, negative publicity and hold-ups in land negotiations and planning. Last month it emerged that costs had risen by £10m to £185m and the funding shortfall to nearly £56m, and the Garden Bridge Trust delayed the expected completion date by a year to 2019. Last week the trust's plea to transport secretary Chris Grayling to extend its £15m funding to continue to underwrite the project did bear fruit, but Grayling cut the amount to £9m, leaving another £6m to be found from private supporters.
However, as contract growers for large landscape projects, Deepdale and Palmstead said setbacks are par for the course. "Delays with these projects are never nice but it's something that we're so used to," said Deepdale managing director Matthias Anton. "We've had it with Kings Cross, with Canary Wharf, with the Olympics. If something is six-to-12 months late it's almost expected. That's part of the whole package really."
Almost a third of Deepdale's 18ha site in Sandy, Bedfordshire, is a holding facility for trees grown in Air-Pots and ready to go whenever the project can take them. It has been holding trees for the Kings Cross regeneration for more than five years, with potential call-offs next spring, and some not expected to be requested until spring 2018.
"We've seen those that are here five or six years now. That's unusual to be that long. Normally we can expect them to be here 12-24 months. We try to cover ourselves, obviously. They give you the ideal delivery date and you know that's not going to happen. We try to cover ourselves for six-to-12 months so we're ready for it in case it happens."
He added that Deepdale clients come to the nursery for its expertise but also experience with big projects. Deepdale costs in any likely delay so the client is not hit with a rapidly rising budget.
Palmstead marketing manager Nick Coslett said: "The delay isn't an insurmountable issue and it will be dealt with within the contract that we've got. It's very common with some of these contract grows that contracts slip. One nice thing about the Garden Bridge is we've got lots of time. I don't see this as a problem.
"The money for plants is such a small part of these projects but it is one of the things most affected by change to the programme. Will the plants still be viable? We've yet to start the bulk of the growing. Changes to the programme at this early stage are not an obstacle for us."
Should it go ahead, the Garden Bridge will benefit from trees that have had more time to acclimatise. Once on site they will be "in a highly exposed area. It's extremely windy and water is limited," said Anton.
"Our nursery is exposed to the wind and the elements there. If some trees are not going to make it there, they are not suitable for the bridge. We try and identify any particular risks before they go on the bridge because it will be difficult to change things afterwards."
Both men remain upbeat about the project. Coslett likened it to the London Olympics, which both nurseries supplied. That had been unpopular with sections of the public, with the cost to the public purse being a key concern, but public opinion was transformed once the games opened.
"Look at the reaction people actually had to the Olympic Park and look at the success since the transformation stage," said Coslett. "There have been six-million visits to the park since and plantings we contributed to are still there."