Below is the bee flora section from the FIBKA website, – Rebecca Dixon is currently compiling a small article for Tribes on planting for bees in the west.
Ireland has a narrower range of native plant species than most neighbouring countries. The main reason is its earlier separation from the European mainland by the rise of post-glacial oceans.
The climate is cool, temperate and oceanic, but warmer than normal for its high latitude due to the influence of the Gulf Stream current. Rainfall averages 115cm over 220 days evenly distributed throughout the year, with less in the East and more in the West and on mountains.
Average wind-speed is very high; this and the frequent rainfall give disproportionate importance in the Irish bee flora to plants with a long flowering period and pendent flowers whose nectar is not diluted by rain.
The geology of the midlands is mainly Carboniferous limestone covered by limestone glacial till. The soils derived from these tend to be alkaline. Mountains, which are concentrated near the coasts, are mostly of older sedimentary, metamorphic or igneous rocks that produce acid soils.
There can be a wide range of different soil, climate and habitat types within a small area, and most bee colonies have several within foraging range
Bees collect nectar and pollen from flowers. The nectar is converted into honey, the bee’s energy-producing food. The pollen supplies proteins, vitamins and minerals that are essential for growth, especially in the larval stage, and for body development and maintenance in the adult bee.
Irish beekeepers get surplus crops of honey from a small number of plants: White Clover, Blackberry, Lime, Ling heather, Bell heather, Hawthorn, Sycamore, fruit blossom (e.g. Raspberry), Oilseed rape, and Knapweed.
Some of those plants are restricted to certain localities; heather requires acid soils such as bogland or mountain areas. Other plants such as Clover, Blackberry and Hawthorn are more widespread.
Modern farming practices affect bee plants; silage cutting may reduce or almost eliminate a honey yield from Clover if the crop is cut as it starts to flower, and heavy use of nitrogenous fertilisers and/or slurry stimulates grass growth at the expense of clover.
Severe cutting of Hawthorn and Blackberry in hedges will reduce the flowers. Overgrazing of hills in past years has destroyed extensive heather sites. On the credit side, the introduction of oilseed rape has benefited many beekeepers.