Dennis Ayling explains his proposal for a tree corridor between Hampstead Heath and Primrose Hill.
For another article by Dennis Ayling, see A New Retail and Nature Partnership to Beat Climate Change.
The greenwalk from Totteridge to Hampstead Heath is well established. It follows the Dollis Brook and then the Mutton Brook to Hampstead Garden Suburb. It continues through the Garden Suburb via Little Wood and Big Wood to Hampstead Heath Extension. Once across the Spaniards Road, it's possible to follow the two spring-fed headwaters of the River Fleet. Both of these streams have been dammed to form a series of ponds. The Highgate Ponds to the east can be followed to Gospel Oak. The Hampstead Ponds to the west lead to South End Green. From Hampstead Heath, the River Fleet flows south underground to feed the River Thames. Therefore, it would appear our greenwalk terminates at the charming southern fringes of Hampstead Heath.
The southern exit from Hampstead Heath onto South End Road
Well, not quite. There is a dormant country corridor that, if substantially enhanced, could extend our greenwalk further. Instead of the ideal river wildlife corridor, which we are currently denied by the burial of the Fleet, there is potential for an urban tree corridor to take us on towards the River Thames. Let us, for a moment, hop to Limehouse Basin where the Regent's Canal joins the Thames. The Regent's Canal is an established greenwalk and wildlife corridor currently being bettered by Thames21. If we now hike back from Limehouse, along the towpath through the East End and towards King's Cross, we will come to Camden Lock. A little further still, will bring us to Regent's Park and the London Zoo on the south bank of the canal and Primrose Hill Park on its north side. A glance at a map will show that there is a relatively small urban area between the northern edge of Primrose Hill and Hampstead Heath's southern fringe. If this built up interruption was bridged with a tree corridor(s) [https://arboristnow.com/news/urban-trees-nature-s-highways-for-wildlife-in-2024/] we would have our complete greenwalk from Totteridge to the Thames.
As it happens, Hampstead has long been referred to as leafy Hampstead. Trees in the high street reach across the width of the road to merge and form a green canopy. The same green moniker could be applied to Belsize Park, slightly down the hill from Hampstead High Street. It, too, has always been a leafy district. I lived in a modest Hampstead flat during the 1940s and 1950s. As a child, running free on the Heath, I developed a love of Nature. Later, I attended Haverstock Comprehensive School at Chalk Farm and became acquainted with Primrose Hill and the London Zoo as well as the Regent's Canal between them. Sometime in my youth I came to see them as a continuum. It registered with me that my morning saunter to school, down Haverstock Hill, was the paved link between the green of Hampstead Heath and that of Primrose Hill and Regents Park. I think it is long overdue, given the climate and biodiversity crisis, that this early vision is turned into an environmental reality. Of course, there are a number of well established walks in the Belsisze Park area. There is even a designated street route between Primrose Hill and Parliament Hill. I am envisioning something altogether different and much more ambitious – a multi-lane wildlife corridor to urgently address both climate change and biodiversity loss.
The UK is one of the most nature-depleted counties in the world. Alarmingly, biodiversity loss is still continuing at the present time. Confronted with this dramatic and devastating loss of vital wildlife during my lifetime, the most resilient green link possible needs to be established between the Heath and Primrose Hill. It is essential to develop multiple uninterrupted dense tree corridors through the urban zone between these two green habitats. Doing so will simultaneously address the parallel crisis of climate change. We are now facing more frequent heat waves of greater intensity and duration. A really significant tree canopy will not only reflect solar radiation but provide shade as well as the cooling effect of evapotranspiration for city dwellers. It will also greatly reduce the absorption and then re-emission of solar energy by road and building surfaces. More frequent and more severe flooding is another deadly consequence of climate change. Trees in large numbers help reduce urban flooding by absorbing water through their roots. Tree roots also create channels in the soil. These macropores, which allow rainwater to infiltrate the soil more effectively, reduce surface runoff and therefore the risk of flooding.
The Camden country corridor I imagined in my youth, long before the current desperately diminished state of our wildlife, must become an immediate priority. It requires not only looking at any gaps in tree planting but also a variety of underplanting including in kerbside Suds. The protection of many magnificent garden trees, shrubs and other wildlife-supporting plants needs to be included. Residents have to be informed about the high worth of their properties to a wildlife corridor and incentivised to participate in creating and maintaining it for both wildlife and citizens alike. Every means to ruralise this urban interruption must be explored. Are there places where layered hedging would work? Are there buildings and surfaces that would support climbing plants to bolster pollinators and provide bird nesting sites? Both hedges and climbing plants shelter invertebrates. These creatures serve a crucial role at the base of the ecological food web. Are there buildings where wet green roofs could be employed? They help to diversify the local habitat and absorb rainwater, reduce runoff, and thereby alleviate urban flooding by slowing down water flow and allowing it to evaporate. Bioswales and rain gardens are another way of ruralising the urban landscape. They are supportive of biodiversity and would mitigate flash flooding due to climate change induced deluges. Belsize Park would be a park and no longer just in name.
The most direct and leafy route by road from the southern fringe of Hampstead Heath to the northern edge of Primrose Hill begins by stepping off the Heath into South End Road. The bottom end of which is deprived of trees in part due to the railway tunnel serving the local station. However, South End Road is very green around the memorial fountain just before you turn onto Pond Street.
South End Road
As you ascend Pond Street, the massive Royal Free Hospital looms over the road, but it does have large trees and a strip of garden running along its front. Two thirds of the way up the hill is a pedestrian passage on the hospital side that passes by Hampstead Green – a small triangular meadow with scattered trees. It is managed for wildlife and uses a mowing scheme that allows the wild plants to flower in support of pollinators.
Hampstead Green
This passage leads on to Haverstock Hill, which descends towards Chalk Farm. There are many magnificent trees both on the roadside and in gardens flanking this road. Some recent tree planting has been done, too, however gaps remain, and much more could be achieved to ruralise this main road. As you descend this hill, it has a well established leafy square just before the local tube station. Perhaps this could be enhanced with planting at pavement level. A water garden served by a bioswale is a possibility. Radical rural enhancement could turn Haverstock Hill into Camden's country corridor.
Haverstock Hill
As we continue downhill and pass Antrim Grove the branches of one massive plane tree reach across the width of the road. Why not have an overarching leaf canopy here – as in Hampstead High Street – towards the top of this same hill? Carrying on down to England's Lane, there are more arboreal gaps to fill. As we pass the Sir Richard Steele Pub, the absence of trees is more marked, as it is further down the hill.
Sir Richard Steele Pub, Haverstock Hill
Why not aim to create an overarching tree canopy the length of Haverstock Hill, especially as it now has cycle lanes? The twin crises of biodiversity loss and climate change call for radical ruralisation of our towns. Turning right into Steele's Road we continue along our relatively leafy route. Pollarded planes line both sides of this peaceful road.
Steele's Road
As we branch into Fellows Road, there is an arboreal gap before trees overarch the road to form a short, leafy tunnel. The final stretch has several more gaps but ends with two giant planes on the corners.
Fellows Road
Here we turn left on to the busier Primrose Hill Road. It is quite leafy on the right hand side, largely due to garden trees. A reminder of the vital role local residents can play in creating and sustaining urban green corridors. However, there is plenty more room for tree planting to create a true arboreal wildlife corridor.
Primrose Hill Road
Shortly, Primrose Hill Road crosses Adelaide Road and again with arboreal gaps brings us to the northern end of Primrose Hill Park. It should be noted Adelaide Nature Reserve, on the railway embankment, is close by and should be incorporated into this primary branch of Camden's country corridor.
Primrose Hill Park, Primrose Hill Road
Potentially, there is a second green corridor traversing this urban barrier that separates Hampstead Heath and Primrose Hill. It begins by stepping off the Heath at the top end of South End Road and walking up Downshire Hill. There are no roadside trees on this relatively narrow road. However, there are quite a few in the front gardens of the houses on the north side of the road. I believe the back gardens of these houses, in themselves, are supportive of wildlife. The parallel Keats Grove is a similar narrow road with very leafy gardens. Where Keats Grove links with Downshire Hill, the latter widens. The top, wider length of Downshire Hill has a solitary plane tree. I believe this end of the hill could accommodate more street trees. Turning left on to Rosslyn Hill, again there are many garden trees as well as some roadside trees. Relatively recent tree planting has filled some gaps, but I would suggest there is a need for more roadside trees, especially towards Hampstead Green. The same applies to the stretch between Hampstead Green and Belsize Avenue. A right turn on to Belsize Avenue brings us into another foliage-covered way until we approach Belsize Park Gardens where it thins out somewhat. Turning left and continuing along our second selected green corridor, the trees of Belsize Gardens become even more sparse. Along this road the trees, including a few magnificent specimens, are mostly in the gardens. There are only five or six mature plane trees on the roadside and one or two recently planted rowan trees. Surely, many more of similar smaller species could be added to the length of this road. On reaching the junction with England's Lane, Belsize Gardens ends and Primrose Hill Road begins. In this wider road I counted only one kerbside tree before Primrose Hill Road crosses Adelaide Road. It is true, there are some large garden trees on this stretch but it needs some street trees to give continuity of foliage along its length. After crossing Adelaide Road, almost the same can be said of the final stretch of Primrose Hill Road right up to the entrance of Primrose Hill Park.
Helpfully, all these routes can be explored virtually on Google Earth.
A quick way to visualise the layout of these potential multiple tree corridors between Hampstead Heath and Primrose Hill is to place your right hand, palm down, with your thumb open to the side. The thumb now stands for South End Road and Pond Street leading to the index finger, which depicts the length of Haverstock Hill pointing towards Primrose Hill. The thumb could also be a representation of Downshire Hill and Rosslyn Hill, leading to the knuckle of the index finger. The four knuckles serve to trace Belsize Avenue, while the middle finger stands for the sequence of Belsize Park Gardens and Primrose Hill Road leading to Primrose Hill. The ring finger and small finger signify other parallel turnings off Belsize Avenue pointing in the direction of Primrose Hill too. In the face of rapidly accelerating climate change and biodiversity loss, this simple model illustrates how an environmentally-enhanced Belsize Park area could serve a vital helping hand to both Nature and Humanity.
Dennis Ayling
Dedicated to my kind Kiwi friend, Ronnie