Geranium rozanne - top plant for bees?
G. rozanne with lasioglossum and passing hoverfly
I have very mixed feelings about geranium ‘Rozanne’ coming top in our research to find the plants that attract the most bes. With a second years' worth of data, geranium Rozanne is now confirmed as attracting more bees than any other plant I have tested. Calamint does run it a very close second though.
I resisted testing it for several years for a rather irrational reason: it had been so hyped by winning ‘RHS plant of the century’ that it put me off. It’s not easy for a small nursery to sell it either because it’s difficult to propagate and still under plant breeders rights which means you have to pay licence fees to produce it.
But now that I’ve been growing it in the research bed for 3 years (I don't count bees until the plant is mature) and observing how the insects interact with it, I still have mixed feelings about it. I toggle between the joy of seeing all the tiny solitary bees it attracts and being a bit cross that it’s a sterile plant and the bi-product of extensive human intervention.
G. Rozanne's sterility is one of drivers of its high ranking in the research; because it is sterile it continues to flower for several months trying, and failing, to create seed. This is also one of the reasons it’s so valuable, aesthetically, to gardeners.
However, the amazing thing from the pollinators’ perspective is that its simple, accessible, open flower shape still produces nectar. This makes it perfect for short-tongued insects of all types but it mainly seems to attract:
solitary bees - I found lasioglossums, chelestomas, the smaller osmia caerulescens (blue mason)
honey bees
short-tongued bumblebees - mainly common carders and some early bumbles
various hoverflies
meadow brown and small tortoiseshell butterflies
I have just 3 plants in my allocated square meter of ground but, by the end of August, these will have spread through other plants to cover at least 2 square meters of area. This is the other reason that Geranium Rozanne is scoring so highly; masses of flowers and a long flowering period.
It still doesn't feel right for a ‘designer plant’ to top the rankings but there is really no denying its value both for gardeners and for bees. Regardless of all that, we sell rozanne in trays of 3 or 6 in our plants section when we have stock available.