Green Roof Update

There's a good reason we don't have stairs up to our green roof. It's one of my happy places - if I didn't have to drag my ladder out of the garage every time I ventured up there I'd disappear for days. Can you blame me?!

We built the house coming up for 10 years ago now and, just like a meadow, the green roof changes year by year. This year Birsdsfoot trefoil and White clover are the big thing. It all needs minimal maintenance because it was carefully designed and installed - we don't generally water it and I take a hand scythe up there once a year. I pull the odd dock too.

Although we originally planted it with plug plants, all sorts of things have blown in - most noticeably the grasses and - of all things - chives. This year Wild carrot made a welcome appearance for the first time. More bizarrely perhaps are the animals. How did this chap get up there, for example?

The flora is quite different to what we have on the heavy clay below. We planted Stonecrop, Agrimony, Kidney vetch, Hypericum and Echiums up there, for example. That's in addition to the stalwarts you 'd find below on terra firma - knapweed, plantain, Black medick, Oxeye daisy etc... Nothing special but lovely - and cracking for biodiversity.

There were a few butterflies and hoverflies up there this afternoon but a lot of bees - three types of bumblebee as well as a party of honeybees and - happy days - the Jeff Bezos of solitary bees, a wool carder bee. There are - unsurprisingly - a lot of spiders, and I nearly fell over a pied wagtail.   

I've wittered on a fair amount about green roofs over the years. The need for them is increasingly obvious, but what I sometimes forget is how lovely and engrossing this constructed world can be.  

I can also reflect on how this artificial mini landscape has helped increase the biodiversity in our little patch. Before we came our two acres of Somerset was I guess what you might call rewilded - scrub and rough grassland. We had a lot of voles, but limited insect species and no amphibia at all, other than a few toads. We had a bat survey before we knocked the old cottage down and the ecologist said how depressed he was to hear no bats around the house at all!   

Most of the land was then transformed into a building site, but now it's a combination of green roof, formal garden, wetland features (along with the green roof, slowing water run off), forest garden and meadow, adding hedges and ponds - as many different habitats as we could cram in. We have a deliberately diverse range of native and interesting wildlife friendly ornamental plants and fruit bushes/trees.

As a result we've recorded many more new invertebrate species than I can identify. I'm not a dedicated recorder or even half competent entomologist, but the ones I'm confident enough to name include five species of solitary bee (our nesters are full to bursting), including one nationally rare and two locally rare - so there will be many more. Most recently these included a flurry of Colletes similis, drawn to our Tansy:

We have three new butterflies, along with a rare moth. We have a variety of impressive looking sawflies and solitary wasps, bush-crickets and grasshoppers, bazillions of hoverflies and a fair few bats. The family of grass snakes is a pretty good indicator we're doing something right too, even though I fancy our newt population suffers!      

Ours is a man made landscape designed to encourage as much biodiversity as possible. It's hardly manicured, but what we did and do makes it much more biodiverse than the "wild" patch here before - and of course much more beautiful. Most elements of it need regular management and all of it - apart from a small area of scrub - was planted or sown. The hedges are trimmed in 3 year rotation after laying, meadow areas cut in August and over winter, willows pollarded, fruit trees pruned. This place is not wild, but it's delivering much more in terms of "biodiversity and environmental services" than a completely rewilded equivalent could ever have done.