Please read the introductory page in the “Real Botany of Desire” for the background to why I’m listing the observed insect friendly flowers that bloom during this month, and which seem to be the most popular with the groups of insects which frequent our  garden in West Wales. It’s tricky to choose just a top 5 of our favourite insect friendly flowers from a long list for this month, but Geranium macrorrhizum, native Aquilegia vulgaris, native sea campion, Silene uniflora, apple blossom, Malus domestica, and Allium ‘Purple Rain’ are currently our favourites.

(As with previous months, there is an overlap with the flowers from April’s monthly folder).

If reading the introduction is a click too far, then briefly, there’s a huge issue with loss of wild flowers as agriculture intensifies and mono-cultures prevail. This impacts on all the insects which rely on flowers as food sources. But all flowers aren’t equal in their appeal to insects, or particular groups of insects, (e.g. honeybees, bumblebees, hoverflies, moths, butterflies) and many nursery bred plants have been designed to be attractive to our senses, not insects.

Some flowers are useful both as pollen and nectar sources whilst other flowers simply provide just one of these insect ‘foodstuffs’. This simple record is to help gardeners think about this issue, and maybe plant more flowers to help our very diverse native insect groups. I’ve found that many of the best plants seem to be some of our native wild flowers which in other respects also have real garden merit. Equally there are many plants from the other side of the globe which are preferentially favoured over native flowers at certain times of the year – there’s no simple easy guide to their relative appeal.

The positive spin offs from incorporating more insect friendly flowers in our gardens apart from the appeal of seeing the insects themselves, will be better pollination of our crops, garden flowers and consequently, seed set. With the added bonus of more varied wildlife in our gardens, since insects are at the bottom of many animal food chains.

It’s certainly not exhaustive, and if you know other flowers which have equal appeal, which are not listed here, do please let me know, and I’ll trial them up here as well. This work started a couple of years before my blog began in March 2011, but previous to that I’d produced the UK’s first DVD-ROM guide to Garden Moths “In A Different Light”. This project attempts to widen that work in a more general way.

Another point to ponder if you actually stand and watch honeybees, bumblebees or any other insects working in the garden, is how quickly they discover which flowers are their preferred ones from all those available. None of them you observe will ever have experienced the seasonal flowers in a temperate garden before, since both flowers and insect visitors have such relatively short lifespans, yet within just hours of emerging as adult insect forms they develop clearly defined favourites, which can change from day to day, or even through the day, often to the complete exclusion of many flowers which we may find attractive.

It’s been estimated too, that a vibrant hay meadow can have over 40 species per square metre, and over 500 flowers per square metre, during the peak flowering season, (from mid-May to early August), which is a huge floral resource. (Watch this Plantlife video, produced by their current botanical specialist, Dr. Trevor Dines, for more about the value of wildflower meadow restoration, and their species diversity.  https://www.youtube.com/watch?v=Dd5rIxIWQTA). Click here, and here, for two fascinating papers from researchers based at the National Botanic Garden of Wales, on the relative values of different plants as nectar sources for honeybees, both locally and from around the UK.)

As I mention elsewhere, the actual numbers of flowers of a single plant type growing together, and their position in the garden (e.g. sun, shade, shelter from wind) can also impact on how favoured the flowers are by your garden’s insect population – probably because sunshine and warmth can affect nectar and pollen production and release, as well as the actual temperature the insect will experience whilst visiting a particular flower.

Not only does Red Russian kale make a great late winter green vegetable up here, but the flower shoots are also delicious, as an early purple sprouting alternative. And if you leave some of them to open and bloom, not only do you get seeds for next year, but the flowers have huge appeal for flies, bumblebees, honeybees and butterflies. A fantastic nectar and pollen resource. Other brassicas probably have similar appeal.

A native solitary bee on the same plant at the same time as huge numbers of other insects.

Apart from Orange-tips, Anthocharis cardamines, and 2012 and 2013 has been a really poor year for them after a bumper 2011, (none at all seen in 2013 here), we see few butterflies in May or June most years other than Large, Small and Green-veined whites, Pieris brassicae, P. rapae, P. napi. This recently emerged Large white also seems to enjoy Red Russian kale nectar.

Pieris forrestii ‘Wakehurst’ flowers about a month later than P. ‘Forest Flame’, so nicely extends the flower season, which the bumblebees really appreciate. It’s a great nectar source for them and certain fly species. In the late springs of 2013 and 2021, Skimmia ‘Kew Green’, a male non-berry forming cultivar of the shrub, proved to be the most popular flower in the garden for visiting honeybees, although it grows in part shade. Bumblebees will also visit.Also still flowering were a few Pasque flowers, Pulsatilla vulgaris, with honeybee and bumblebee visitors.A few Helleborus x hybridus flowers sometimes linger on into May, receiving honeybee and bumblebee visitors.I’ve occasionally seen honeybees, and an unidentified fly species, visiting the pretty flowers of Tulip clusiana ‘Peppermint Stick’ and Tulipa ‘Little Beauty’ below – it’s very unusual for me to see any insects visit any of our tulips. Did this reflect greater nectar production by the flowers than in a normal year, because of stronger sunlight, perhaps?
Dandelions, Taraxacum spp., continue to appeal to some native mining bees, and flies, throughout the month. Flowering currant, Ribes sanguineum, is often mentioned as being attractive to insects, and for the first time in 2013, I’ve actually seen some insects on its pretty flowers in our garden. Here a solitary bee. It gets bumblebee visits as well, but the bees rarely seemed to stay on the flowers for very long, hence my lack of images. Lamium maculatum ‘Chequers’ continued to bulk up between the apple trees in 2013, and continues to be a favoured bumblebee nectar source, but I’ve yet to see any other insects visit its strongly coloured flowers – frankly were it not for its obvious bumblebee benefits, I don’t think we’d have ever grown it, but it’s really lifting the appearance of the shady area between our spirally grown apple trees.

As this image shows, Euphorbia amygdaloides ‘Purpurea’ continues to flower into May, and appeals to flies, some native bees and this interesting bee, probably a species of blood bee, Sphecodes.

For bumblebee appeal the Pulmonarias have to be the number one plant in our spring garden, and this variety, P. ‘Trevi Fountain’ started flowering in 2012 in the first week of January, (more like April in 2013!) and it was still going strong in May. Throughout this time it’s the number one flower choice for at least 4 different early flying bumblebee species. So we keep planting more of it, and it’s fortunately easy to split and divide in spring or autumn, and thrives in shady or sunny moist spots. However, you don’t often see other insects on its flowers, just occasionally the odd honeybee. It fascinates me that one flower can be so preferred over others, particularly since none of these insects will ever have experienced any of these any of these flowers before. Insect tongue length clearly plays a part, but it’s not just that simple.

The common Daisy, Bellis perennis, grows in our mossy lawns, and if you don’t cut the grass as short or as often you get a few flowers which are visited by some flies, and occasionally bumblebees for nectar and pollen.Our Aubrieta continues to bloom well into May, and the main beneficiary is usually the spectacular Bee-fly, Bombylius major, though honeybees sometimes visit.

Along with Pulmonaria, and Geranium macrorrhizum (see below), Ajuga reptans ‘Burgundy Glow’ pictured above, is the third fantastic spring nectar flower in our garden for bumblebees. On a warm day the bugle flowers will attract huge numbers of bumblebees. I’ve also occasionally seen a honeybee on it, but rarely native bees or flies. But its bumblebee popularity, as well as its ability to spread easily and drift through other plantings, means that we grow masses of it, in sun or shade.

The image above is, so far, the only one I have yet of a non-bumblebee bee, visiting bugle flowers.

Bugle, Ajuga reptans ‘Burgundy Glow’, was also visited by Orange-tip, Anthocharis cardamines, and Green-veined white, Pieris napi, butterflies in 2012, in what was a very poor spring butterfly year.

We grow quite a lot of Bergenia in areas of the garden, but this is the only time I’ve seen an insect on their flowers, so it doesn’t rank as a popular flower. More recently I have seen occasional honeybee visits – we probably don’t have enough of it in flower at any time to ranks as a significant flower. If you look closely at the flowers, a lot of the petals have evidence of brown spotting, petal damage, probably from bees’ hooked talons.

In a cold spring like 2012, 2013, and 2021, pear blossom, Pyrus communis, is still out here in May, and can attract a wide range of pollinating flies, bees and bumblebees. (In 2013, the first apple/pear blossom didn’t open until 13/05/2013. Will there still be time for any fruit to develop?)

Apple, and crab apple blossom, Malus domestica, and Malus sylvetris, is equally appealing to a diverse insect range of bees, flies, bumblebees and butterflies.

White honesty, Lunaria annua var. albiflora, continues to flower into May and attracts many different flies, a few bumblebees, and some butterflies, particularly the Orange-tip (In 2013, I have yet to see any males in the garden by mid May). With lots of other flowers open in our garden, it’s now less popular as a nectar source for bumblebees than earlier in the year. All those insects makes it a good place for a spider to get weaving.

We grow some Oregon grape, Mahonia aquifolium, which doesn’t really thrive in our garden in its current location. Mahonia have a reputation of being a good early nectar and pollen source, but this is the only photo I have of a bumblebee visiting its flowers. Many years later, after moving the plants to a sunnier spot, I could add an image of honeybees too.

Right at the beginning of the month, both bumblebees and some flies visited the flowers on female holly (Ilex) bushes.

Hover fly on female holly flowers. For the first time in 2013, I saw honeybees and an unknown small bee, probably a Nomad bee, Nomada spp., visiting the flowers of mossy saxifrage, which grow in many parts of the garden, but which have usually finished flowering by mid May. 2013 sees them just getting going by this time, and usually it’s just various fly species that we see visiting them.

Simple Aquilegia vulgaris flowers are the favoured flowers for many bumblebee species in May, once they begin to flower, along with

Geranium macrorrhizum, which when in bloom, is the other preferred bumblebee flower attracting huge numbers. G. macrorrhizum is also one of the most popular flowers in May in the garden, with visiting honeybees, and even early arrived, immigrant Silver-Y moths, Autographa gamma, in a warm spring.

Some other early saxifrages attract flies, though not usually honey or bumblebees.

However common London Pride, Saxifraga x urbium, seems very attractive to solitary bees, honeybees, hover flies and wasps.

Wasp on London Pride.

Most Rhododendron varieties seem valued by bumblebee species, from March through to June, though are less often visited by honeybees, which is perhaps just as well since honey made from too many Rhododendron flower visits, is potentially toxic to people.

From April through until October, Sea campion, Silene uniflora, is a native flower which has great appeal for bumblebees and several moth species, though it gets fewer visitors later in the season.

Bumblebee on Kidney vetch, Anthyllis vulneraria. This is another native flower, which, in spite of our acid conditions, grows well in full sun and partial shade.

Native Thrift, Armeria maritima, is a really popular native flower with both bumblebees and butterflies, and along with the other coastal plants (as above – Sea campion, Yellow-horned poppy and Kidney vetch) which we sow into the gravel at the end of our yard, makes a great insect feeding area in full sun, out of an otherwise barren spot.

Welsh poppies, Meconopsis cambrica, appeal to many flies and bumblebees.

Meconopsis cambrica also seem to be a preferred pollen source for yellow-legged solitary mining bees and honeybees.

After Geranium macrorrhizum, Geranium phaeum is the next most popular Geranium species for some of our bumblebees in early summer.

Geranium phaeum also appeals to honeybees.

For the first time in 2012, I’ve seen insects visiting the pretty flowers of Brunnera macrophylla ‘Mayenne Blue’, but only honeybees. The equally sized pink flowers of native Geranium lucidum in this picture, were ignored.

The similar sized blue flowers on Omphalodes cappadocica, are typical of the smaller flowers visited by bee-flies, which guide in their extraordinary tongue with incredible speed and accuracy.

As are the varied forms of Primula sieboldii. In this garden, bee-flies seem the major pollinator of these flowers.

When it begins to flower, from mid May onwards, Pyrenean Valerian, Valeriana pyrenaica, is loved by many flies, honeybees, and bumblebees, which can become plastered in its pale lilac pollen.

A poor image in low light, but included here because flowering in May, (not the more usual April, 2013), at least 2 species of bumblebees were visiting our ‘Invicta’ gooseberry flowers, as well as the usual pollinators which seem to be queen wasps, below.

The pretty, scented single flowers of Rosa rugosa ‘Frau Dagmar Harrtop’, the earliest into bloom of any of the roses we grow, had honeybee visits in 2012. Apparently roses only have value as pollen source flowers, apart from the native Dog rose, Rosa canina, which does produce some nectar. An unknown form of grape hyacinth, Muscari armeniacum, which doesn’t really thrive with us, continued to attract honeybees and bumblebees into May.

We struggle to grow Alliums well in our garden.  A. ‘Purple Sensation’, above, certainly gets regularly visited by both honeybees and bumblebees. In 2020, we trialled A. ‘Purple Rain’ after reading reviews implying it was better at returning in following years, and it turned out to be a fantastic flower, both visually for us, and the insects, especially honeybees. It’s a sadly sterile hybrid of A. christophii and A. ‘Purple Sensation’. Pictures below. A. christophii is equally favoured by insects, but less reliable here, long term, and flowers a little later, running into June.

 

But in 2014 the 100 or so Nectaroscordum/Allium siculum recently planted just a yard from a Cotoneaster horizontalis were almost exclusively visited by great numbers of large tree wasps (Dolichovespula sylvestris), although there were huge numbers of honeybees and bumblebees in the garden nearby. Elsewhere in the garden we’ve seen bumblebees visit these flowers in June, so whether other insects were scared off by the large numbers of big wasps around the Nectaroscordum flowers, or whether they will visit when the Cotoneaster flowers are finished, remains to be seen. As with the huge numbers of bumblebees earlier in the year, most of these late May big wasps will have been overwintered queens, recently emerged. It seems that the  very mild winter weather has allowed significant numbers to survive. Click here for my post on this wasp from August 2013. Quite what this will mean for tree wasp numbers in the garden in August this year remains to be seen. Perhaps we will have to wear protective gear when gardening! For now the wasps, which have a reputation for being aggressive, seem too intent on gathering nectar to be bothered about the photographer.

One of the best willows, I think a form of Salix viminalis, is this unnamed cultivar we were gifted as a few rod cuttings. In May, if coppiced annually, it produces masses of lengthening, snake like flowers from the axils along each stem, which is perhaps 1.5 metres long. The flowers open gradually from base to tip for about 10 cm. The yellow pollen never lasts long, since honeybees and bumbles raid it voraciously, but it’s a great resource, coming well after the goat willows have finished flowering and is really visually attractive too for several weeks. Someone may even be able to confirm a name a name for it? Most suppliers will cut these wands for basket making in the winter, so never see the flowers. We now leave this cultivar until the flowers have finished and then cut it back hard.

Lady’s smock, or cuckooflower, Cardamine pratensis, is a very pretty native flower which appeals to many insects, though rarely in our garden many bees, and is one of the larval foodplants of the spring flying Orange-tip, Anthocharis cardamines, butterfly.

In around 2013, we began exploring Camassias as a mid spring flowering bulb, and have found many are visually delightful, all seem to thrive in our moist climate in sun or part shade, and most seem to appeal to honeybees and bumblebees. The first, and therefore most numerous form for now, is Camassia leichtlinii caerulea. The only down side to this plant is that it sets very few seeds, but the bulbs clump up really well, so we can forgive it that!

Another first for 2012 was seeing this honeybee on the beautiful pink rimmed flowers of Deutzia x rosea ‘Carminea’. Interestingly Deutzia are in the Hydrangeaceae, which as a family seem to be generally poor bumblebee, and solitary mining bee attracting flowers. I’ve yet to see any other insects on this plant.

In 2012 this unnamed Weigela has turned out to be one of the most popular flowers in our garden in May for bumblebees, along with Geranium macrorrhizum, Ajuga, and Aquilegia.

Erodium manescaveii, is another Geranium like flower, but a stork’s bill, not a crane’s bill, which is a big hit with bumblebees, and also with us for its very long flowering season and ability to gently seed around.

Geranium himalayense did have a few honeybee visits in 2012, but it’s nothing like as popular as G. macrorrhizum or G. phaeum.

Dicentra spectabile f. alba always gets a few visits from bumblebees, though it’s not one of the most popular May flowers for them in our garden.

Other Geraniums which we grow lots of, seem to have less appeal for bumblebees, though these bumblebee look-alike flies are attracted to them.

Bronze leaved Polemonium yezoense ‘Purple Rain’ (Jacob’s Ladder) has been a really attractive flower for bumblebees, honeybees and flies, though is not reliably perennial here. Unlike our favourite Polemonium ‘Lambrook Mauve’, which flowers for much longer, and in spite of being sterile, is easy to propagate from cuttings, so is now one of the early summer follow on plants along the retyred matrix garden’s path.

Native Germander speedwell, Veronica chamaedrys, which we grow in profusion as ground cover, mixed in with other suitable plants, does attract small flies, though not in any quantity any form of bee, and small bumblebees, honeybees and solitary bees will occasionally visit its pretty blue flowers.

When in flower, the rather common Cotoneaster horizontalis buzzes with bumblebees, honeybees, wasps, flies and solitary bees. Fleetingly, it creates an insect generated din in the garden, and has that rare appeal across many insect genera. This all contributes to excellent pollination and thus berry formation, and its potential to be an invasive plant in some habitats.

Masses of dramatic flowers are produced on Crataegus laevigata ‘Crimson Cloud’, a hawthorn cultivar, but it only occasionally attracts a few fly visitors.

Though considered to be a pernicious garden weed, in its place, native Creeping buttercup, Ranunculus repens, is a much visited flower by moths, like this day flying Mother Shipton moth, Callistege mi, bumblebees and other flies.

We have a lot of Euphorbia plants of a few cultivars, and I rarely see insects visiting them, but in 2021 found this attractively marked Ichneumon stramentor wasp, visiting Euphorbia dulcis ‘Chameleon’. This quite uncommonly recorded insect is a parasite of the larvae of a few moths including the locally common Large yellow underwing moth. The adult female wasp locates the caterpillars and lays its own eggs into them. The wasp’s egg hatches and consumes the caterpillar before pupating to emerge the following year as a new adult wasp. The only other photo on i-Spot of this wasp, actually nectaring on a flower, when I looked, was also feeding on a Euphorbia. So perhaps these flowers appeal to this insect, or Ichneumons more widely?

 

Last updated 13/05/2021