Practising nectar sampling using flowers from the garden
During the recent spell of gloriously warm weather, my winter wardrobe was hurriedly stashed away in a corner of my cupboard, the summer sandals were dusted off and dinner was only ever a decision between veggie burgers or veggie sausages on the barbeque.
Alas, the warm weather didn’t last and I’ve embarrassingly had to retrieve some woolly, winter essentials a good seven months earlier than planned.
The unseasonably warm weather did, however, mean that there was a flush of new growth and early flowering in the Garden. Well timed too, as I was due to sample nectar on the Plants for Bugs plots.
You’ll remember that our nectar sampling involves inserting uniform bore glass tubes (called capillary pipettes or minicaps) into flowers, mimicking the action of visiting pollinating insects. Each inserted minicap draws nectar through the narrow tube by capillary action. Nectar samples will be sent to researchers at Newcastle University to be analysed for their constituent sugars (glucose, fructose and sucrose) with results helping provide advice on what’s best to plant for pollinators.
On the plots, less than a handful of native and near-native species were in flower. From left to right: Rhodanthemum hosmariense (Moroccan daisy), Armeria juniperifolia (sea thrift) and Primula vulgaris (primula).
After collecting three flowers from each flowering plant species per plot, I returned to the lab for sampling. However, despite being armed with a multitude of variously-sized minicap volumes, I was presented with seemingly empty flower after empty flower. Perhaps some hungry pollinators had already visited my flowers? Perhaps the burst of warm weather had meant flowers opened early but offered little nectar reward? I’m not sure yet.
Given the low nectar volumes, known quantities of water were added to flowers and the solution (water and any available nectar) was drawn up for analysis.
I’m due to sample again in around 6 weeks so I’ll have a better idea of the possible explanations for these low nectar volumes then (let me know if you have any thoughts on this)! By then, I can only hope that the winter clothes will be back in the cupboard and the cooking of most of my evening meals will again necessitate the use of a match, some charcoal and a fair amount of burning.