Depending on which calculation you choose, autumn has either already arrived or will be here in a fortnight’s time. ‘Meteorological autumn’ began on September 1, but ‘astronomical autumn’ starts on September 23 and ends on December 21. The meteorological system of fixed three-monthly seasons is easier for keeping comparative statistics, but the astronomical dates reflect the tilt of the earth's axis and its orbit around the sun.
This year the distinction is a bit academic. With piles of leaves on every pavement and berries already ripening, we’ve been experiencing a ‘false autumn’ since late July thanks to the drought and the extreme heat of the summer. The Guardian ran a very lyrical piece on the false autumn two weeks ago which might interest you.
Please keep watering!
Despite September’s cooler days and heavy showers, our youngest trees will still need watering throughout the month to make up for the punishing summer weather. The trees planted on grass should be OK, but very little of the recent rainfall will benefit saplings on the pavement.
Southwark’s maintenance contractors were watering every week during the heatwave, but they’ll be cutting down to just a single visit in September, when they’re scheduled to also clear weeds and apply mulch. So please don’t put your watering cans away just yet. At this time of year you can safely halve the volume you apply each week to around 20 or 25 litres per tree, or alternatively lengthen the intervals between soaks.
Cargo bike eases the burden
We’ve been trialling an electric cargo bike for the past few weeks to see if it makes long-distance watering easier and quicker than carrying water by hand. It’s sturdy enough to take 20 five-litre water containers (enough for two trees in summertime) and the electric power assistance gets us up the hills, reloading at various points along the route.
We rent the bike from OurBike, a community cargo bike sharing scheme supported by Lambeth and Southwark councils, every Thursday. We’ll probably make our last outing of the year on September 15, between 10 a.m. and 2 p.m., so if you’re interested in coming along to help do let us know.
Rentals are very cheap. The first two hours are free and each subsequent hour costs just £3. You have to take a short induction course with OurBike first before they’ll let you take one out yourself, but once you do there are cargo bikes hosted locally at:
Perks and White, the coffee shop at Herne Hill station on Railton Road (the bike is kept beside the noticeboard in front of Brockwell Art Services)
Koala Coffee, at 64 Railton Road
Rye Books, at 47 Northcross Road, East Dulwich, and
Karavan Eco, the eco-friendly shop at 167 Lordship Lane.
We’ve found that it sometimes helps to use a funnel and a short length of hose for trees where the green watering bag is difficult to reach. You can buy 7-inch wide funnels like the one in the picture from Herne Hill Builder Centre on Station Square, Railton Road, and 15 mm diameter garden hose from BTC plumbing supplies at 45 Norwood Road. Just squeeze the hose into the bottom of the funnel and poke it into the slit in the bag.
Sunray Avenue oak tree condemned
We learned at the beginning of September that one of our biggest, most beautiful and - in Herne Hill at least - most unusual trees is to be felled. It’s a northern red oak (Quercus rubra) and it lives at the top of Sunray Avenue. You’ll find it on the other side of the road from the house at no.4, on the grass in front of the Hillcrest estate garages. It’s got an identical neighbour which was taken down some years ago but is now regenerating strongly from the stump.
At a distance the tree looks like it’s in excellent health, with a full canopy of large, finely cut leaves. But move closer and you’ll see three clumps of bracket fungus around the base. That’s a clear indicator of disease. A sonic tomograph - a non-invasive scan for trees - commissioned by the council showed significant internal decay near the base of the oak and a big cavity. The obvious danger is that a tree weakened to that extent could topple over.
The oak is scheduled for felling on September 14, but at the prompting of a local resident we’ve been talking to the tree officers about alternatives to complete removal. They’ve agreed to consider leaving the stump in situ for its ecological benefits and say they can also deliver the logs for seating at the Denmark Hill estate community garden. They’ll also include a large tree to replace the red oak in the 2022/23 planting programme.
Other oaks in Herne Hill
Oaks aren't generally considered suitable for planting on hard surfaces, where they often don't flourish, and you'll only find three of them on the streets of Herne Hill.
Two are on Elmwood Road, where it meets Beckwith Road at the Half Moon Lane end. The big, dark and dense tree above the bench there is a holm oak (Quercus ilex), an evergreen with holly-like leaves and tiny acorns. And in a large tree pit by the brick wall around the flats is a tightly upright variety of the English oak, a Quercus robur Fastigiata Koster planted in 2020 ('fastigiate' means columnar).
The third pavement oak is another evergreen, but much smaller and less frequently seen: a cork oak (Quercus suber) outside Bessemer Grange school on Nairne Grove. There's a photo of the extraordinary bark (traditionally used for wine corks) in our May 2020 post.
There's another big holm oak in the grounds of the Denesmead estate, just past St Paul's church behind the bus stop. It's exceptionally wide, with five conjoined stems, but it's not popular with all the passengers waiting for the 68 or 468. The pigeons up in its branches aren't especially careful about where they deposit their droppings.
You’ll also come across four oaks on Sunray Avenue, all in the big open space opposite the junction with Casino Avenue. Seen from Casino, the two trees fronting the main road are a sessile oak (Quercus petraea) on the left and a Turkey oak (Quercus cerris) to the right, pictured together in the item about tall trees in our May 2022 issue. Along the perimeter road around the same grassy square are two young oaks.
The English oak and the sessile oak are both native trees, very frequently found in woodlands and emblematic of the countryside. The sessile tends to have a longer, narrower, straighter trunk than its cousin the Quercus robur, but the only sure way to tell them apart is the way the acorns grow: on the sessile oak they don't have any stalks, on the English oak they do.
You'll find two more oaks on Red Post Hill: in the grassy crescent outside no. 77 and outside the Cassinghurst flats at the bottom of the hill. And finally, there's a stately oak in the forecourt of the Baptist church on Half Moon Lane. It's definitely worth a look the next time you're crossing Winterbrook Road.
A tricky fox problem
Several of you have pointed out the serious damage being done to the recently planted London plane (Platanus x hispanica) on Elmwood Road, where it meets Frankfurt Road. Foxes have been repeatedly digging deep holes in the soft soil that are literally undermining the tree and exposing the roots.
The planting contractors have tried putting an additional cage around the original protection, but it hasn’t stopped them. Sprays designed to deter foxes don’t work either. We’ve suggested that the council build a proper pit around the plane, edged with concrete borders or covered in a flexible, permeable material. At the moment the tree is just sitting in the big irregular hole left when the big stump there was removed last year.
If you have any other suggestions for dealing with the fox problem do let us know.
Planting season approaches
Eight weeks from now the 2022/23 tree planting season will officially open. We’ve prepared a detailed spreadsheet for the council showing the 72 trees we currently expect to see planted in Herne Hill during the four-month season, so please take a look when you have a moment. It will change as more trees are added.
Our newest tree
Just as the autumn/winter planting programme was being drawn up, the last new tree of the 2021/22 season - the 51st - finally arrived in July. It’s a lovely, tall red maple (Acer rubrum 'Red Sunset') and it stands in the grass at the far end of the entrance drive to the Pynnersmead flats near the foot of Herne Hill. The ‘red sunset’ in the name is a clue to the colour that the attractive three-lobed leaves, with their gently rounded profile, take on in autumn.
The maple inventory
The newcomer at Pynnersmead joins a small but growing collection of maples in the neighbourhood. Two other species not previously seen locally were planted in May this year, both Cappadocian maples (Acer cappadocicum) - one on the front lawn at Pynnersmead and one at 36a Carver Road. They have unusual ‘lanceolate’ leaf lobes with a rounded base, each topped with a spike like a Prussian officer’s helmet, and they colour well in autumn.
There’s another rarity on Stradella Road, also three-lobed: a Trident maple (Acer buergerianum) at no. 48. We featured its amazing autumn colours a couple of years ago and you can see from the latest photo below that the leaves are already starting to turn.
The trident is a maple that’s suited to the scorching summers ahead, classed as ‘moderately tolerant’ of drought by the Forestry Commission's Right Trees for a Changing Climate database. Others that can withstand a lack of water are the sycamore, the silver maple and the Norway maple, all of which have a presence on our streets, and the native field maple (Acer campestre), four of which should soon be appearing in Nairne Grove.
Most of the 100-plus species of maples are known for their stunning, multi-segmented foliage and their brilliant autumn tints. Some, the ‘snakebark’ maples, also have vividly striped bark. But every type of maple has ‘opposite’ leaves, meaning that they’re arranged in pairs on the stem, and their fruit is always a ‘samara’ (or ‘key’), where the seed is attached to a wing that’s easily carried by the wind.
You’re probably familiar with the samaras of the sycamore (Acer pseudoplatanus), a very familiar species in city and countryside that rapidly colonises railway embankments. Children like to throw the fallen seeds in the air, which then spin like tiny helicopters. We’ve got 14 sycamores, our commonest local maple, in the area, mostly on the Delawyk and Elmwood housing estates. The sycamore’s leaves are less sharply defined than our other maples and look rather drab and dark in summer.
In the late summer and autumn the characteristic hanging clusters of dry samaras, seen here outside flats 88-106 on Elmwood Road, provide more interest and soon the sycamore foliage will become a pleasing golden yellow.
Next most frequent here are the 11 silver maples (Acer saccharinum). You can find two of them side-by-side at 59 and 61 Herne Hill, at the junction with Frankfurt Road; three of them in a line where Stradella Road meets Half Moon Lane; and six more further down Stradella, where it turns towards Burbage Road. The Stradella trees are enormous and grow great thickets of shoots around the base that need pruning annually. Their angular, deeply cut, five-lobed leaves have sharp teeth around the margins and also colour a soft yellow in autumn.
And finally, we have 10 Norway maples (Acer platanoides) scattered around the district, although the one outside 55 Herne Hill is in very poor condition and might not last much longer. The leaves are spiky in outline and turn to yellow, and sometimes red, in autumn. There’s a tall, neatly domed specimen at 7 Danecroft Road, a purple-leaved version at 19-21 Red Post Hill and this healthy young tree at 39 Casino Avenue, in the top cul-de-sac.
Pruning diary
We’ll be organising minor maintenance sessions in the coming weeks - mostly pruning of unruly shoots at the base of the tree or small branches that are damaged or impede passers-by. It’s worth knowing which trees you can safely prune in autumn and winter and which you should leave alone.
The rule of thumb is to prune when trees are dormant. That means when they’re not growing, the sap isn’t rising, the leaves have turned colour or fallen and they’ve finished flowering.
The majority of our Herne Hill trees, on streets, housing estates or open spaces, come into this category and should only be pruned in autumn or winter. But there are a few exceptions, which we’ll list for you here in order of their Latin names. The guidance comes from the Royal Horticultural Society.
Acacia (mimosas): prune soon after flowering.
Acer (maples): only in winter, when fully dormant.
Aesculus (horse chestnuts): autumn to midwinter, but minor pruning in summer is OK.
Albizia (Persian silk tree): spring, as growth begins.
Ilex (hollies): mid- to late summer.
Juglans (walnuts): midsummer to before midwinter.
Magnolia (magnolias): early to midsummer.
Populus (poplars): late summer or early autumn.
Prunus avium (wild cherries) and Prunus dulcis (almonds): remove dead wood in summer and suckers in early spring.
Prunus cerasifera (cherry plums): midsummer.
Prunus serrulata (all Japanese flowering cherries) and Prunus serrula (Tibetan cherry): early to midsummer.
Quercus ilex (holm oak): mid- to late summer.
Sophora japonica (pagoda tree): summer.
Tilia (limes): midsummer to midwinter.
Zelkova serrata (Keaki or Japanese zelkova): late winter, but minor pruning in summer is OK.
Let us know if there are any cherries on your street that need attention and we’ll organise a pruning session before the cold weather sets in.
Paul Millington, 44 Red Post Hill, 07939 052 383
Jeff Segal, 12 Warmington Road, 07990 566 056
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