Trees are good for our health. Of course, as horticulturists, we already knew that. But now it is official. The Office for National Statistics says that large amounts of air pollutants were removed by trees, plants and grass during 2015, which meant there were 7,100 fewer lung- and heart-related hospital admissions and around £1bn was saved in medical costs.
Vegetation also helps mitigate the impact of heatwaves —and that is official too. The parliamentary Environmental Audit Committee’s report Heatwaves: Adapting to Climate Change, published in July, states: "Green spaces have been proven to reduce the urban heat island effect."
It also notes that "urban green space has declined in England" and, following Met Office projections that UK summer temperatures could regularly reach 38.5°C by the 2040s, the report warns that high temperatures "will threaten the well-being of an increasing number of vulnerable people" due to higher incidences of cardiac, kidney and respiratory disease.
The many environmental benefits of trees include soil stabilisation, water management and habitat provision. The value of trees in economic terms is also now recognised. Trees in London’s Hyde Park have an amenity asset value of £137m, according to recent work commissioned by The Royal Parks and undertaken by arboricultural consultancy Treeconomics.
Then, of course, there is the value of the timber itself. The British forestry sector contributes more than £4.1bn to UK GDP each year and employs more than 64,000 people. Yet we still import more than two-thirds of the timber the country needs. Timber products manufacturer Forest Garden of Hartlebury, Worcestershire, warns that the country must dramatically increase levels of softwood planting or face shortages in the future. Timber is also needed for the paper and biomass industries.
Clearly there are sound reasons for planting more trees and there are some significant schemes going ahead. In China, for instance, around 60,000 soldiers have been assigned to tree planting as plans are acted on to create at least 6.6 million hectares of new forests this year alone. In the UK, the charity Trees for Cities (formerly Trees for London) completed its largest and most diverse planting season last spring. It planted close on 73,000 trees in 49 projects across London and in 25 projects in 20 other towns and cities from Redruth in Cornwall to Edinburgh in Scotland. In the North West, Oldham Council has appealed to local landowners to join its planting campaign to build resistance to flooding.
Forestry planting in Scotland also received a boost with a streamline approvals process leading to more than 10,000ha of new forestry being approved last year — an increase of 2,500ha on 2016. Actual new woodland creation in Scotland last year amounted to 7,100ha — 78% of the total for the UK and 60% of it productive. But that still falls short of the annual planting target of 10,000ha.
Trees: more needed for woodland, urban green infrastructure and housing schemes - image: James Coles & Sons (Nurseries)
If all the messages currently coming from parliamentary committees, health bodies, environmental organisations and timber business are acted on, we could see more woodland created, the boosting of urban green infrastructure with avenues and street trees, more parks and green spaces, and housing developments involving landscape plans for amenity planting schemes. But, while there are signs of increased activity this year, everyone has been struggling with hot weather and drought, and the effects are also being felt on the nurseries.
At James Coles & Sons (Nurseries), key account manager Vince Edwards has had an extremely busy year until the hot weather caused a slowdown. "It’s just because it’s been so hot," he says. "A lot of schemes have not been factored in with the landscaper or contractor to pick up the post-planting watering contract. If it’s a housing contract, it could be left to the site agent or for a groundworker left on the scheme. If it’s a private job, you hope the owners organise something before they pop off for two weeks’ holiday."
Coles Nurseries is the UK’s largest grower of trees and shrubs for the amenity and commercial markets. Based near Leicester, it operates across seven production sites with a total of more than 500 acres in the East Midlands and has the capacity to grow in excess of 1.2 million trees and 2.4 million shrubs for supply to landscapers, garden designers, wholesale nurseries and local authorities for projects ranging from new housing and business parks to show gardens.
Edwards is optimistic about the future and especially for the coming bare-root season. "We are quoting for jobs now and we often get very good advance notice of those quotations turning into orders. Looking ahead to November onwards, we have an awful lot of work on the books," he says.
English Woodlands: bare-root and container-grown woodland trees and shrubs - image: English Woodlands
Impact of the weather
At Majestic Trees, near St Albans in Hertfordshire, the weather has also had an impact. The nursery specialises in trees grown in Air-Pots and offers more than 400 varieties from four years old up to 150, from 4ft tall to 40ft and with girths from 20cm to more than a metre around the stem.
Speaking in July, managing director Steve McCurdy said: "It was going brilliantly in the autumn until we had 150mm of snow one night. Then it rained on and off for three months, killing off the end of winter/early-spring planting. It picked up in April, May and June were excellent and July sales were good but shipped sales have been postponed because of the threat of hosepipe bans in different parts of the country. We are not going to hit target for July and August is not looking good either."
McCurdy hopes that the Government will follow through with the greening of the urban environment. He would also like see rainwater harvesting become the norm in new builds. "We’ve been talking about water shortages for years. It should be automatic for all new builds to have rainwater harvesting," he says.
There is also optimism at English Woodlands. The nursery, at Heathfield in the Sussex Weald, offers a wide range of landscape, amenity and woodland trees and shrubs, bare-root and container-grown, together with planting accessories. Sales director Joanne Carter says: "I am certainly optimistic about this year and we are getting good enquiries across all sectors — developments, farmers and landscapers — particularly for bare-root native stock and the larger specimen trees. We have seen growth in sales of native species to satisfy planning for new developments and there is a lot of building going on." Last year saw the highest number of homes built in a decade — up 13% on 2016.
While native species are selected for the landscape planning element of new housing developments, evergreen shrubs are proving popular for gardens and show homes. Edwards suggests that is largely down to the way the housing market is viewing sales.
"I think it’s due to the developers wanting to have a 12-month sales period. They need the gardens and site looking nice all year round so whenever people visit or buy a house there is something impressive rather than traditional deciduous hedging which, out of season, doesn’t look very inspiring," he says. "The open spaces take care of the native element but architects are using a broader plant palette around the house to provide that all-important year-round interest."
In terms of size, five-litre plants continue to grow in popularity. "We’ve certainly noticed demand
for five-litre plants increase," says Edwards. "It is pleasing to see that architects are insisting on five litres and not just accepting two- or three-litre plants."
It seems that cost no longer takes priority. "It comes down to the competitive nature of the housing market, with large house builders wanting to make a big statement and lift the size and value of the plot-planting and also the show home," adds Edwards. "For open space to meet planning requirements, architects want 12/14 or 14/16 trees and they are not going accept six/eight or eight/10 to manage costs."
Along with native trees, McCurdy reports that sales of multi-stems are stronger than ever. He also suggests there will be more housebuilding over the next few years because of changes in countryside policy.
Nurserymen, perhaps more than most, are conscious of the threats of imported pests and diseases.
But is the threat influencing what architects and landscapers specify? "There is definitely more awareness of pest and disease threats and there are some signs that people are selecting to reflect concerns over pests and disease, but not as much as there needs to be," says McCurdy.
Edwards sees more emphasis being put on climate change than on pest and disease threats. "Climate change is the question that keeps cropping up. We do still get requests for things like olives, which, as a company, along with other large nurseries, we do not trade in. It is too much of a threat to the UK market."
Climate change, along with pests and diseases, must be acknowledged in future planting schemes, but never before have we had so much evidence about the benefits and values of planting trees and shrubs. So, let’s get planting.