Roofs & Rambles

A windy June afternoon visit to the wonderful meadow roof above St. James’ tube station I was escorting Gary Simpson from Australia. This green roof, designed for rare bugs – bees, spiders and beetles,  also has a few arrays of photovoltaic panels. It is is certainly looking wonderful with the cornfield annuals swaying in the wind.

It is always a pleasure to share our London green roofs with visits form abroad. This roof so far this year has had visitors from Qatar, Sweden, Italy and the US. Gary had come from Melbourne and Ben Nicholson of the Australian Green Roof Association had put him contact with me. We couldn’t have asked for a better day. Beautiful sun, blue skies with chasing clouds and a good breeze that swayed the flowers. June has been relatively wet so everything was in full bloom. Although we have noted a few bees on the roof in previous visits today there were over twenty different bees of at least 5 species on the roof. Although there were only two Vipers bugloss in flower they were certainly the most popular of the plants on the roof, although the cornfield annuals can a good second. The Kidney vetch is only just coming into flower and will soon be a nectar larder for the bees. Many of the herbs/forbes are still to flower – majoram, thyme, basil, lady’s bedstraw, common toadflax and selfheal - so there will be plenty of nectar up on the roof as the summer progresses.

Although I still get questions about vegetation growing up in front of photovoltaic cells on green roofs – one can see that it has no impact on the PVs what so ever. We also know that the green roof element provides a perfect micro-climate for the cells to work at maximum efficiency when the sun is at it’s best. PVs lwork ideally with an ambient temperature of 25degrees C around the panels. The evapo-transpiration from the plants and soils helps maintain this sort of temperature. Green roofs and PVs- good ecosystem services thinking.

Managed to get a couple of shots of bees, though they were a little bit flighty and of course the wind was blowing the flowerheads about like nobodies business.

Cornfield annuals are a real delight to the eye. Though most people highlight the cornflower, with it’s radiant blue flower head, I have always had a soft spot for the corncockle. It really is a beauty.

It’ll be two weeks at least until I visit again. I am sure there will be another change when I come back in July. Different flowers in bloom and perhaps different bees. And perhaps a butterfly or a moth to entertain.