Horticulturalist, beekeeper and friend of Bee Good, Mark Patterson from ApiCultural writes about the flowers that are so important for our British bees.
We are now in late spring and proper warm weather should have finally arrived, although earlier in the month it was distinctly chilly. Over the past decade, our springs have generally been warmer than usual with the early May bank holiday weekend of 2018 subject to temperatures of 28 degrees - the warmest May on record. These sort of temperatures used to be associated with high summer but are increasingly common now in late spring. The advantage to bees is that the warm weather brings out more flowers, more nectar and easier foraging but warm springs can also result in changes to the timings which some flowers and their pollinators emerging growing out of sync. Its now more important than ever to plant our gardens with a range of flowers that will provide a long succession of blooms to ensure there is always something useful to bees in flower all season.
The early spring flowers are now going over and the forage baton is passed onto the late spring and early summer flowers.
By May cherry Laurel Prunus Laurocerasus will have almost all gone over but their smaller later flowering variety ‘otto Luyken’ is now in bloom and its flowers should last into early summer. Like its larger cousin, it sports extrafloral nectaries on its leaves which may yield nectar early in spring/summer.
The cherry trees are now almost all gone over and replacing them are the May Blossom also known as Hawthorn. It’s said if you get a good flow on the hawthorn you can relax and not worry about the rest of the seasons' flow. Some of my bees in west London are very close to 40 hectares of Hawthorn and I have definitely noticed a strong flow of nectar coming into the hives at this time of year.
Alongside the Hawthorn, Mountain Ash and White Beam, both types of Sorbus tree are flowering, Wild Dog Rose, Dogwood and Gorse are flowering. One of the best-cultivated roses at this time of year is Rosa x Xanthina ‘Canary Bird’ which has lovely large simple canary yellow blooms which all manner of pollinators flock to. Laburnum is also in flower right now and a popular forage source with long and short-tongued bees alike. The short tongue species tend to steal the nectar from the rear of the flower whereas the longer tongued bees like Anthophora plumipes and Bumblebees go in from the front. The plant is toxic to humans but bees love it. The blooms are short-lived and only appear for 2-3 weeks at most.
The Horse Chestnut flow should last a few more weeks. Many of the white Horse Chestnut appears to be more advanced than the Red Horse Chestnut which should provide forage for a couple more weeks yet. Look out for their brick red pollen coming into the hives. Horse Chestnuts are among several spring flowers which actively communicate with the bees indicating if their individual blooms contain nectar or not. In white Horse Chestnut the blooms are white with creamy-yellow markings. As the individual blooms are pollinated and fertilised the cream markings turn to ink and red indicating to the bees that nectar is no longer available here and not to waste their efforts but instead to focus on the still productive and rewarding creamy-yellow marked flowers.
Horse Chestnut flowers attracting a foraging Honey bee
Holly continues to flower and soon Geulder Rose, one of our two native Viburnums will also start to bloom. Around housing estates, urban parks and gardens, amenity shrubberies like Cotoneaster, Ceanothus and Pyracantha are blooming. These are magnets for bees. The sweetly scented blooms of mock Orange Choiysia are now flowering and these are visited by a variety of different bees. Choiysia’s peak blooming month is May but they will often produce a steady but less extensive show of blooms right through to autumn. Box Leaf Honey Suckle a popular hedge or amenity shrub plant is commonly grown in municipal areas like shopping centre car parks and social housing estates is very good for Honey Bees if the plants are not brutally trimmed in spring. They flower in May and on warm days you will smell them and hear the buzzing of bees working their blooms before you see them.
In gardens, Scented Clematis will come into flower growing along fences and trellis. These strongly scented varieties often smell divine and the blooms covered in bees.
Herbaceous plants in flower this month attractive to bees include Astrantia, Dicentra, Aquilegia, Hardy Geraniums (probably the best for bees is dusky Geranium) Echiums, Euphorbia, Thymes, Saxifrages, Nepeta, Stitchwort, Oxe Eye Daisy, Vetches, Purple Comfrey, Red Valerian, Scabious and Knapweeds (Centurae).
Late spring bulbs like Alliums and Camassia are good forage for bees this month.
Red Girdled Mining Bee on a Greater Stichwort
One of my Favourite times of year to visit woodlands is May as there is so much colour from all the spring blooms. These are in turn great for bees. Wood Anenemone which will be now over in the south will still be in bloom in more northern areas and alongside them, Greater Stitchwort-an attractive white flower who’s blooms are attractive to the nationally scarce Red Girdled Mining Bee Andrena labiate. After planting some stitchwort in my London garden a colony of these delightful bees appeared and have been growing in number year on year. Other woodland flowers like Honesty, Hedge woundwort and Native Aquilegia will be flowering.
In more open wild habitats Clover, Birds Foot Trefoil, Sainfoin and Oxe Eye Daisy will come into bloom.
If you haven’t already then erect your plant supports now to support herbaceous plants as they grow tall over the coming months – These will help to hold up taller plants which may droop or collapse later in the summer. Erecting them now gives the plants a chance to grow through them and looks allot less unsightly than if left to later on when twine would have to be used to tie them up.
Keep on top of weeding. May is a warm month and weed seeds will germinate and spring up at a quick pace so regular weeding will be required if your treasured garden plants are not to be overrun by fast-growing weeds.
You may want to top up mulch on your gardens this month to help retain moisture in the soil and keep annual weeds at bay.
Spring bulbs grown in containers may be looking tired by now so they can be moved elsewhere in your garden out of sight and other pots containing in-season flowers brought out to replace them. Your bulbs in pots if deadheaded, watered and fed well will bloom again next year.
Now is a good time to prune early spring flowering shrubs like Flowering Currant, Sarcococca, Viburnum tinus, Winter Honeysuckle and Daphne. They will have plenty of time to produce fresh new growth from which next spring’s flowers will bloom from.