You’d expect the Botanic gardens to be full of colour in July and they do not disappoint, with a glorious bed of annuals perennials between the glasshouses and the Carboniferous garden and pots of richly coloured red, blue and purple Salvias near the visitor centre.
The Echium pininana I enjoyed so much last month are setting seed now but the annual seed mix planted beside them, above the pond, is full of colour.
The signboard next to this area proclaims it to be a BSD ‘Diamond Jubilee’ seed mix of 24 species of annual flowers, from Boston Seeds, 12 of which are recommended by the RHS as ‘Perfect for Pollinators’ but I think the labels may have got confused – the colour palette I see in front of me is much more subtle, with lots of white Ox-eye daisies, purple Corncockle and blue Viper’s bugloss! It’s actually a native mix rather than the exotic one on the signboard and so arguably much better for our pollinating insects.
I know from Dave Goulson’s book, The Garden Jungle, that suitability for pollinators also depends on how the seeds are grown. If herbicides have been used to clear the ground beforehand, or pesticides are applied to keep the plants looking perfect, then the plants can actually be toxic to the pollinators they are supposed to support. The instructions for the seed mix on the signboard say to ‘sow into bare soil after clearing all existing plants and weeds from the area’, so I hope this has been done manually rather than with a herbicide!
Possibly the biggest surprise this month was the area round the picnic benches near the ‘Park and Ride’ entrance to the gardens. Previously this has been mown regularly but this year, although wide paths have been mown to allow access to the picnic benches, large areas have been left uncut and are now a sea of colour – willowherbs, knapweed, thistles, purple- and yellow loosestrife, meadowsweet, bellflowers, toadflax and more. The diversity makes me suspect there has been a little planting here too but the plants are all native wild flowers and are truly buzzing with bees, butterflies and other pollinators.
The other delight in less-manicured parts of the gardens at this time of year is a sizeable population of Broad-leaved helleborines, Epipactis helleborine. These helleborines were also doing a good job of attracting the wasps on which they rely for pollination by providing a plentiful supply of intoxicating fermented nectar in the flower cups known as hypochiles.
I guess the balance in a Botanic Gardens between leaving space for wild flowers and showcasing exotic plants from all over the world is a tricky one to strike but I, for one, am very much enjoying the space being made in Durham for our native wild plants. Showing visitors how attractive these can be, to us as well as to pollinating insects, must surely help in the battle to persuade people that wildflowers (or weeds, as some call them) have an important place in gardens and parks in maintaining biodiversity.