Last week the RHS published the first paper from its "Plants for Bugs" four-year study in the Journal of Applied Ecology
. It's an interesting read, not least because so little research has been done in this area. According to the RHS website the key messages for gardeners are:
The best strategy for gardeners wanting to support pollinating insects in gardens is to plant a mix of flowering plants from different countries and regions. Emphasis should be given to plants native to the UK and the northern hemisphere, though exotic plants from the southern hemisphere can be used to extend the season (there are a greater proportion of exotic plants flowering later in the season compared to UK native and northern hemisphere plants) and provide nectar and pollen for some specific pollinators. Regardless of plant origin (native or non-native), the more flowers a garden can offer throughout the year, the greater the number of bees, hoverflies and other pollinating insects it will attract and support.
This is all good stuff, and I absolutely agree with it. But - and you knew there was a but coming - I do have two complaints about the way this is being spun. First off, there's a question of emphasis. The accompanying social media blurb from the RHS says:
Native plants alone may not be the best option for supporting pollinating insects in UK gardens!
Well, yes, but non-natives alone DEFINITELY aren't. I can't see the headline reading "Exotic plants alone are definitely not the best option for supporting pollinating insects in UK gardens" Perhaps I'm just being over-sensitive, or perhaps not. The RHS are hardly likely to discourage people from growing exotic cultivars, after all - it's what they do. Secondly, identifying what provides the "best" nectar and pollen for certain pollinators is very helpful, but it's not the bee all (geddit?) and end all. Take butterflies, for example. Like some solitary bees and many other "bugs" they have developed relationships with very specific plants. In the case of butterflies it's as food plants for their caterpillars; Yellow Brimstone caterpillars eat Buckthorn, for example. I know some butterflies and moths can adapt to non-native plants, but not all. It's also true that some of our own insects like non-native plants for non dietary reasons; the wool carder bee just loves Stachys byzantina, with which it lines its nest. In other words, choosing plants for bugs is not just about native v. non-native or pollen and nectar. It's more complicated than that. As usual.
One of our honey bees enjoying a non-native scoff from Geranium 'Rozanne', a favourite in the garden