Horticulturalist, beekeeper and friend of Bee Good, Mark Patterson from ApiCultural writes about the flowers that are so important for our British bees.
In April many of our true heralds of spring have begun to flower. Although March is officially the first month of spring, its often not until April that we really start to notice spring-like weather with the days becoming substantially longer and warmer.
Among the most important of April blooms is the pretty pink Cuckoo Flower Cardamine pratensis. This dainty little pink flower is a true sign that spring ‘proper’ has arrived. It’s an important nectar plant for many pollinators and the main food plant for the larva of the Orange Tip Butterfly – a species sadly in decline. This plant was once widespread across the UK enjoying pride of place in many spring wet meadows but due to modern farming practices and draining of land has sadly declined a great deal.
Orange Tip Butterfly
Deadnettle, Dandelions, Coltsfoot, Primulas, Wood Anemones, Green Alkanet, Comfrey and Lungwort are at last now coming into full bloom. The later two, in particular, are popular with the Hairy Footed Flower Bee. Another flower which I notice lots of small solitary bees on at this time of year is Lesser Celandine. This plant is unusual in the buttercup family (Ranunculaceae) as it is one of the few buttercups that are attractive to bees. Most other Ranunculus have nectar which contains the toxin protoanemonin which bees cannot digest and can lead to May poisoning.
Lesser Celandine, however, is popular with many of our early solitary bees and occasionally Honey bees. Many of the Micro Andrena solitary bees feed on the golden yellow flowers which form vast carpets among cemetery, churchyards and beneath hedgerows. Another member of the buttercup family which bees may visit at this time of year the Marsh Marigold. Many of our early spring flowers are pale yellow in colour- it’s believed that this gives them an advantage over other blooms since the pale yellow stands out more in the dim spring light and stands out particularly well in polarised light - a spectrum of light that we cannot see but bees can see using their three simple ocelli eyes.
As Tulips come into bloom they replace crocus and Winter Aconite which have now gone over, but there are still Daffodils in flower (though they are of little use to our bees), Aliums, Wild Garlic and Muscari (Grape Hyacinth) come into full bloom.
Forget-me-nots are now in full bloom and putting on dazzling displays of sky blue blooms. I often hear beekeepers who have had their honey analysed for pollen content claim that Forget-me-not pollen content is very high in their honeys which leads them to believe that the bees have made honey predominantly from Forget-me-not forage. Whilst Honey bees certainly like Forget-me-nots I don’t think this is the case though, I just think Forget-me-not pollens get over-represented due to the abundance of the pollen grains produced by the plants and their very small size not being filtered out by the bees Proventriculus, so more pollen ends up inside the honey produced. Forget me nots are very clever flowers as they are able to change the colour of the centre of the flower to communicate to the bees when they have been pollinated.
This month across much of southern England Bluebells will be making an appearance and should put on a gorgeous display of blue. Bluebells may be visited by Honey bees and can produce a honey crop but they are also popular with some of the longer-tongued solitary bees. Most Bluebells in urban areas will be the invasive Spanish Bluebell but in rural locations stands of the native species can be found in woodlands. Further north the Bluebells may not bloom until May.
April is when one of the flowers which many beekeepers herald as the true arrival of spring and the start of a new beekeeping season begins to bloom; the Flowering Currant Ribes sanguinium. This plant is a reliable indicator that spring proper has arrived and for me a timely reminder to undertake first proper inspections of my Honey Bee colonies.
Other important sources of forage this month are the willows. The catkins of willow bear copious amounts of sulphur yellow pollen. If your honey bees are returning to the hive dusted in yellow they will most likely have been visiting willow. It’s not just honey bees that visit willow. Many bumblebees and Andrena bees will also collect willow pollen and seem to time their emergence with Willow catkins. Unlike the earlier flowering catkins of Alder and Hazel willow will also produce nectar. If you want to plant a Willow in your garden but lack space for a large impressive tree, then Salix capraea ‘Kilmarnock’ is a good variety to plant. It’s a dwarf weeping type tree so won't grow too large but still produces masses of catkins loved by bees – and you have the added bonus that the catkins are at head-height so you can easily observe the bees visiting them.
Other trees coming into bloom right now include Field Maple, Sycamore, Poplar and Ash. April is when we normally expect to see Cherry Laurel Prunus laurocerasus blooming, many of the small solitary Andrena bees rely on this shrub for pollen and nectar. This plant also has extrafloral nectaries along the underside of the leaf which honey and Bumblebees may visit to forage on during times when there are few flowers in bloom.
As we progress through April we see the first Horse Chestnut blossom. Chestnut produces very distinctive dark brick red pollen which honey bees will collect with enthusiasm. Chestnuts are one of the best examples of how plants communicate with their pollinators; the individual blooms of the flower stalk change colour as they are fertilised to inform the bees that they need not bother to visit that particular bloom. Other trees coming into bloom will include Cherry, Plum and Apple. Black Thorn may continue to bloom into April but is often over by now. On a good show of blooms and on warm days the bees may bring in a crop from this nectar source. At one of my apiaries, my bees have access to about 45 hectares of mostly Blackthorn scrub and they bring back copious amounts of the brown-coloured pollen and can fill a super with honey in little over a week if warm weather coincides with the flowering.
One of the larger gardens where I keep my Honey Bees includes a 34 tree fruit orchard. In April the Apricots, Peaches and Mirabel DeNancy Plum usually flower in early April followed later in the month and into May by the Pears Apples, Victoria Plum and Green Gage.
April is when the autumn-sown Oil Seed Rape will be starting to come into bloom and will flower well into mid-May. Beekeepers either love it or hate it for it can produce an abundance of honey but the grainy texture and tendency to crystallise rock-hard in the comb are drawbacks.
The abundance of forage available in April is important to honey bees and beekeepers as this early food supply allows the colonies to increase in size producing lots of workers who will be ready to collect the abundance of nectar available later in the spring and summer when the main nectar flows switch on.
This adorable little chocolate coloured brown bee is one of the most abundant solitary bees to be found in April. This bee nests in burrows underground and can form large nesting congregations. Often a number of bees will use the same spot to nest excavating a communal burrow or utilising an existing cavity made by a rodent. The individual females will them excavate their own branch burrow in which to make a nest and provision their offspring.
Chocolate Mining Bee
Males emerge first followed a week or so later by the larger females. I often find nesting congregations of this bee in closed graveyards where the bees will nest communally beneath grave plinths and fallen monuments or in community gardens where they nest in the soil seeping between raised beds constructed out of railway sleepers. The nesting aggregations can be large with many hundreds of females nesting on one site.
These bees can’t sting humans so are safe to handle and observe close up. On cold spring mornings when picking up a Chocolate Mining bee you will sometimes find them hard to put back down as the bees seem to like clinging to your warm hands.
They feed on a wide variety of spring flowers including tree blossom, Primroses, Dandelion, Forget-me-nots and violets.
By June they have all vanished and won’t be seen again until the following spring when the next generation of Chocolate Mining Bees emerge to repeat the annual cycle.