blog

Follow our progress running the nursery, watching wild bees, keeping honey bees and creating our own bee-haven in south Oxfordshire

Where are all the bumblebees?

I was talking to my friend, John, the head gardener at Denman College last week and he commented he is not seeing very many bees in the garden yet even though his great bank of catmint is beginning to flower - pictured above. I wandered over and. sure enough, in a 4 meter section there were only two hairy-footed flower bees but not a single bumblebee.  I had noticed the same lack of bees at rosybee so I checked back at my records.

If you have read my blog before you probably know that I count bees regularly to quantify how attractive various plants are to them. So, I am doing my normal thing whenever it seems dry and warm enough: head out with the clipboard and look for bees to count....but there is a notably lack of them.

Its now the end of May and the weather is still grey with a chilly wind coming from the north so I thought that maybe this was putting the bees of but looking back my at notes for the last two years I see that the last two weeks in May were not particularly warm and definitely breezy. The only real weather distinction is that the days were brighter if not warmer.

The solitary bees seem to be about and also the carder bumblebees are putting in regular appearances but I am seeing very few of the other species, where normally I would expect to see early, buff-tailed, and red-tailed bumblebees in greater numbers by now.

I am wondering if the very long wet winter impacted these ground-nesters?

Worker bees laying eggs: doomed hive?

Multiple eggs in the cells indicating a worker bee has laid them

Multiple eggs in the cells indicating a worker bee has laid them

The winter of 2015/6 was bad for the honey bees at rosybee. We took 5 hives into winter although we knew two seemed weak so were not so surprised that those colonies died out, but a further colony then went queenless. This can happen when the queen gets too old during a winter period and unfortunately this queen made no arrangements for a successor. Often this results in no new brood being laid in the hive and so, without intervention, the hive would die.  In our case we had an even worse predicament: one of the worker bees (who are all female but sterile) started laying eggs. A workers eggs can only develop into drones and so, again, the hive is doomed.  The sure signs that you have a laying worker are multiple eggs in the cells. In our case the worker(s?) were very prolific and produced many more eggs than the hive was able to feed and nurture resulting in generations of new eggs being layed on top of withered shrunken older eggs. In the picture above you can see the eggs of different sizes in the cells.

To make matters even trickier, you cannot find a laying worker and eliminate her as she looks just like all the rest.  So what to do...?

We tried merging with another hive - before I read the advise- but unfortunately the queenless bees killed the queen in their new host hive. So realising my mistake I split the colonies again an then tried adding some eggs from another source, but they did not raise a queen (although luckily the hive with the killed queen did). So finally we tried the last resort recommended by the books which is to move the hive away from its site and shake all the bees out of it. The majority returned to old site of their hive where we placed a new empty hive. This seemed to work as we found worker laid eggs in the old hive with just a few remaining bees and no eggs in the new hive....but they are still resisting the idea of raising a new queen. I have just given them one further sheet of eggs as their last chance and fingers crossed.  I would give up but not sure what to do with quite a considerable number of rogue bees anyway. Any suggestions?

Wool carder bees - territorial behaviour

Wool carder male on betony

Wool carder male on betony

This fascinating species of bee (Anthidium manicatum) have very distinct behavior and there are some plants worth growing specifically to attract them.

The males find a patch of plants they particularly like - normally because they expect it will be popular with the females - and set about patrolling this patch as their territory. They can be seen darting about and chasing off other bees that might dare to come along. They will even take on bumblebees that are double thier size. The females are allowed in to forage in return for a chance to mate.

In addition to the normal foraging for nectar and pollen the females also collect hairs (cards) from certain plants that they use to line their egg cells. These plants include stachys byzantina (lambs ears) and hairy verbascums (mulleins).

At rosybee this summer I have been watching wool carder bees fighting over a patch of stachys officianalis (betony) and only occasionally on the stachys byzantina. The former, as far as I can tell, is not hairy and so I guess they are simply defending a prime nectar source. 

They move so fast that photography is difficult but I did manage to catch the above picture. One of the other distinctive aspects of their behavior is that they are able to hover which is really unusual in bees and can help identification if they dont stop long enough to see them close-up.

bumblebee on stachys byzantina (lambs ears)

bumblebee on stachys byzantina (lambs ears)

Calamint - an overlooked herb with great potential for bees

In our quest to find plants that are really good for bees I am always on the look-out for plants that are worth adding to our research. In 2014 I discovered calamint in Cambridge's botanic gardens.

It was early September and the single very mature and woody plant they had was buzzing so frenetically that it very soon caught my eye. In Cambridge it appeared to mainly be attracting honey bees but we have since introduced the lesser calamint (calamintha nepeta) at rosybee and I find it attracts both honey bees and bumblebees, mainly common carders.

Its a member of the mint family and leaves give a scent and flavour that to my palette is a cross between mint and oregano. Apparently it makes quite good tea - which I must try- and is a common seasoning in middle-eastern foods. It spreads slowly but, unlike mint, is not invasive.

In last years research results this plant went straight into 12th place in our rankings with an average of 3.6 bees per square meter and 10 weeks of flowering; not bad for a first year and I expect it to do even better once the plants are more established.

Geranium phaeum - best shade plant for bees?

geranium phaeum- rosybee

geranium phaeum- rosybee

A question I regularly get asked is 'what can I grow in shade for bees'. Allowing for the fact that bees would generally prefer to forage in sun - to avoid their small bodies cooling down - there are some plants that will be happy in shade but still provide value to bees.

Of these plants, the one I find most effective is geranium phaeum, otherwise known as 'dusky cranes-bill' or the very evocative 'mourning widow'.

It is happiest in dappled shade which replicates the edge of woodland and produces a nice mound of foliage often with attractive dark markings.  The foliage spreads up to 50cm across from March right through to October, making it a good groundcover plant.

The flowers arrive as soon as spring begins to warm up and will continue flowering until the end of June; if find that if you cut off finished stems you sometimes get a second batch.

The range of flowers for this plant can be from white, through purple to a very dark maroon which I believe is the 'native' version.  In the right conditions they can hybridise and self seed; the one I do at rosybee has evolved from my garden and is a mix of the dark purple 'lily lovell' and a white one which have resulted in a purple flower with a white centre......delicate but stunning.

The reason I think this is a candidate for 'best shade plant for bees' is that it is currently the highest ranking shade plant in our research and this year sits in 31st place (just outside the top 30) and far above other shade plants.  It attracts mainly carder bumblebees - which are themselves quite tolerant to shade - but also a range of other bumblebees. 

A pile of sand for solitary bees

Stepped sand to provide nest site for solitary bees either horizontally or vertically

Stepped sand to provide nest site for solitary bees either horizontally or vertically

You have probably all seen solitary bee houses in garden centers or even been given one as a gift. You know, those cute little wooden boxes full of tubes or with holes drilled. These are all fine - as long as the holes are drilled to the right size and you put them somewhere very sheltered. But I found out a new fact last week; most solitary bee species prefer to nest in holes in the ground!.

The nest boxes will attract red mason bees, leafcutters and many more but patches of warm dry bare ground is where you will find other species like the tiny lasioglossums. I must have areas like that at rosybee because I have observed ground-nesting bees on the plants but I have been researching how to provide even more habitat for them. The easy answer appears to be to provide a pile of sand.

You will see that I have shaped the sand into steps because some bees like their entrances to be horizontal and others go straight down vertically. The sand bank faces south east and you will see that it is not only sheltered by a fence but we have also used a recycled bed head/foot as supports. for the bank but also to provide even more shelter.  Over time grass and weeds will seed themselves into the sand and will need to be kept short to allow maximum sun to warm up the sand.

I do hope it works.

New to rosybee plant range: Anthemis tinctoria

Anthemis tinctoria and a solitary bee: Colletes species

Anthemis tinctoria and a solitary bee: Colletes species

I have the Denman House (the WI training college) garden to thank for this find. I keep bees in their grounds and am friendly with John, their head gardener so when I check the bees I try and also have a look round his luscious herbaceous borders.  He keeps one section that he calls the 'bee garden' and it is full of herbs and catmint. In this area I noticed that this pale cream daisy was almost vibrating with movement and on closer inspection discovered that it was covered in a range of small to tiny solitary bees. 

Most solitary bees dont really buzz - or if they do its very quietly - and they are so much smaller than honey or bumblebees that its quite easy to mistake them for flies if you only give them a casual glance. Close up, though, you can see the detail and often quite defined bee stripes.

These little miracles are very effective pollinators, in part because when they collect pollen they dont glue it to themselves with nectar, the way honey bees do, and so they drop much more as they go from plant to plant.

I am still working on how to identify which is which but when I find a plant like this which, at that time, had at least 20 bees per square meter it must deserve a place in both our research beds and our shop. The plant flowers for June and July with masses of daisies on fine grey foliage, 60cm tall. See shop

 

Tips for bee-friendly plants: Phacelia proving more frost resistant than expected

After the frosts - borage in foreground and phacelia beyond

After the frosts - borage in foreground and phacelia beyond

At rosybee we have an acre of ground that we sow with strips of borage and phacelia, in succession, to provide a great expanse of bee-fodder over the summer. We have been doing this for 5 years and although we still battle with other local invasive weeds we find that if we let the borage and phacelia self-sow, when possible, we get quite and effective crop of flowers without having to plough and re-sow.

Last autumn was so mild that the self-seeded plants get quite a lot taller than the carpet of seedlings we normally see through the winter. And then last week the frosts finally struck and we had a low of -7C one night.

The borage that really caught in and all semi mature plants are now black and ruined although I can still see seedlings that survived so I think it was the brittle stems that were the weakness. But to my surprise the phacelia, which is not meant to tolerate temperatures below -5C still looks lush and untouched even though it is 30cm tall in places.

Once the soil dries out enough to allow the tractor onto it we will resow the borage and by June the carnage of the frost will be forgotten and the whole area will be buzzing again. Both borage and phacelia are really easy to grow from seed - just chuck them at soil and off they go - and are in our top 30 ratings of plants for bees (see research for full results)

Bee-hive winter inspection

IMG_7131.JPG

On December 28th we had sunshine and a balmy 12 degrees so it was ideal conditions for checking the hives at rosybee. We have 5 hives at present and due to the mild weather we have regularly seen bees coming and going from each hive. As very little is in flower this activity is not likely to yield much in the way of forage  so we fully expected them to have burnt through quite a lot of food, and they have. Two hives were very light so we fed them some of our excess stocks of honey to give them an very quick boost and the others got some candy where needed.

Amazingly, we did spot some bees returning to the hives with some pale buff-coloured pollen on their legs which shows the plants are also responding to this strangely warm weather.

pale buff-coloured pollen on the bee just entering the hive

pale buff-coloured pollen on the bee just entering the hive

We will check them again at the end of January and also do the oxalic acid treatment. We didn't do it last year and paid the price in very high varroa numbers so lesson learnt.

Late flowering borage boosts winter stores for bees

Borage really is an amazingly opportunist plant requiring only a few days of mild weather - above 15 degrees - to germinate seed. We have lots of it at rosybee; we actively cultivate it in some places and then let is seed itself about where it chooses selectively weeding it out where we dont want it.  It tends to always find a home in a corner of the research bed or an unused bit of the allotment.

Each borage plant flowers for about 2 to 3 months depending on the conditions and this year, iwe had a succession of borage sowings in our bee-crop acre that gave us flower almost continually from April to August. After that we harrowed the area allowing the borage and phacelia to self seed for next year. But its been so mild that the first seeding had decided to flower now.

The result is an unexpected carpet of blue in late October and yesterday in dull sunlight with only 13 degrees of warmth the honey bees were working it at a density of 5 per square meter. This seems to be competing well with the ivy and must be giving them an extra boost although the weight of the hives indicate they already have plenty of winter stores.

Solidago and is it good for bees?

tiny solitary bee - one of the lasioglossum species

tiny solitary bee - one of the lasioglossum species

When I first started researching plants for bees in 2010, solidago - Golden Rod - was a plant I found included on several lists recommending plants for bees. Based on this I tried two species - canadiensis and virgaurea. Both produced quite disappointing results attracting flies, beetles and hoverflies but only a very occasional bee. However, once you have planted a patch its easier to leave it than to dig it out and so the canadiensis has stayed in the research bed, ever since, attracting the same range of non-bee pollinators and I removed it from my sales range.

Then this year, one very warm week in mid-August, I found bees on the plant - not just one but several - honey bees and two different solitary bees. And I found them there daily for about a week. Then the plant began to 'go over' and the bees naturally stopped visiting. 

So this leaves me with a dilemma when recommending plants. Do I include solidago, which for one week in five years attracted around 10 bees per square meter making it a medium high attractor....but just for one week? I think that the only solution is to ask others to let me know if they get bees on their golden rod and if possible how many.  Emails on the subject very welcome

Record bee numbers observed: helenium autumnale

   Three honey bees on just one helenium stem

 

Three honey bees on just one helenium stem

Some of you will know that at rosbee we are trying to quanify how attractive various plants are to bees; we monitor all our plants every week and count bee per square meter. 

Today, 21st of August was very warm with only the gentlest of breezes and at 3pm we counted a record number of bees per square meter on our patch of helenium autumnale. It was very difficult to count them as there were so many and they do tend to move about. I called my son to help and between us we counted 3 times each, compared numbers and decided that 32 was a conservative and safe figure. There may have been more bees because, although the majority were honey bees, there were also a considerable number of a very active but tiny solitary bees zipping around and darting on and off the flowers. The tiny bees were mainly lasioglossums - probably fulvicorne - and I have never seen them in such numbers or state of apparent excitement before.

In total I noted 5 species of bee but without being able to photograph the all solitary ones its very difficult to identify the species.

We have been counting bees for 3 years now and an observation of 32 bees far exceeds the previous high of 21.  Other plants also seemed to have move bees than usual with the veronicastrum recording 17 bees which is also a very high number.  I must have been special weather conditions and numbers were much less today.

I am now very excited about how all this data will look when we get to the end of the season: watch out for our results around Christmas time!

 

our square meter of helenium autumnale with 32 bees counted

our square meter of helenium autumnale with 32 bees counted

Seed collection at rosybee

Borage seeds ripening as the stems dry

Borage seeds ripening as the stems dry

This is seed collection season and at rosybee we try and collect seed from all our favorite plants especially those we like to have lots of like borage and phacelia, but also those plants which I find germinate better from fresh seed.

We grow an acre of mixed borage and phacelia in succession to provide a bee-buffet from end of May through to August. Borage is particularly tricky to collect seed from as each flowering stalk will ripen and drop only a couple or seeds every few days and so extends its seed ripening over about 6 weeks. When the borage begins to set seed we collect the whole stem and leave it to dry out slowly in the polytunnel (pictured below); that way more seeds ripen before the stalk becomes too dry and we get more seed. The down-side is that as it dries the prickles which cover the plant become brittle and much more scratchy so its a job that is best done in protective clothing.

The phacelia is much easier; just snap the flower heads off, put them in a box to dry and when they are ready all the seed falls easily to the bottom.

We also collect our own seed for many of the perennials we grow and sell, that way we know exactly what the parent plants are like.

Eryngiums

Spiky dramatic and highly exotic looking, eryngiums are well suited to dry conditions and generally an easy garden plant -  as long as they are not on a spot that you will brush against. They are also excellent bee-friendly plants which flower for most of July and August providing nectar even on the hottest days then fade to leave you with stately seed-heads into autumn.

I grow:

  • the biennial e. giganeum (above) which grows about 80cm high but with giant flowering heads that with their multiple bracts reach to about 40cm across. I have sometimes counted as many as 10 bumblebees on a single plant.
  • perennial e. planum (below) which has smaller flowers that starte ice-green and mature to deep blue

Both attract a range of bumblebees but also some honeybees and butterflies.

dry weather - bad for bees

veronica spicata - supporting bees in spite of the dry weather

veronica spicata - supporting bees in spite of the dry weather

Its been a really dry July so far and I am sure many of you have also noticed that the plants are showing the results; many are finishing flowering early and other just look sad and limp. At rosybee this seems to even include the tough native echium vulgare which has a deep tap root and is designed to cope with very well draining chalk downland, but after flowering for 7 weeksit is looking very crispy now (below)

Another effect of dry weather is that the plants are unable to produce much nectar - its a water based substance and they simply cannot produce it if they are thirsty. This then has a knock-on effect on all the pollinators too. The bees and other insects still keep visiting the flowers but get much less return for their efforts although is some case the nectar will just be more concentrated. Supply a source of water for the bees - shallow dish with gravel for them to stand on - helps but does not off-set lack of the carbohydrate the nectar provides.

I have noticed that the bees at rosybee seem to be zipping from flower to on dry plants as if it only takes a second to clear them out.  There are some other plants, probably the more established ones that they are lingering on though; amongst these are the betony (stachys officianalis), scabious columbaria -both native wildflowers but good for gardens - and veronica spicata all of which are being mobbed by bees this week.

IMG_0228.jpg

Summer arrives at rosybee

the research bed

the research bed

I've been so busy that when I had a chance to walk round our site this week it was almost a surprise to find that summer seems to be here now. I have been working in the research bed, weeding and planting, but somehow I failed to stand back and look at it.

There is now quite a lot in flower in the research bed; foxgloves, wallflowers, salvia nemerosa, nepeta mussinii, knautea macedonica even the agastache - which made it through the winter this time- are all at their best right now and the echium vulgare and veronica spicata are just starting to flower. The echium can be seen in the centre above reaching 5 feet high even in our terrible clay soil.

I particularly love bee-spotting on the foxgloves as you think there are no bees then suddenly a bumblebee will emerge from where it has been completely hidden inside a flower and flit quickly into the next tube.  That makes counting bees on them quite difficult but luckily each bee tends to work multiple flowers before moving on so its possible to track them over a few minutes to see how many there are.

In the wild parts of the site the bramble is just beginning to flower so I know were all the honey bees will be for the next two weeks; I will monitor these timings carefully, this year, as I think the bramble is so attractive that it has an impact on how many honey bees we see on other plants. Having said that our second scale sowing - below - of phacelia and borage is now in full bloom so will give the bramble some competition.

borage and phacelia - half acre with bramble in the background

borage and phacelia - half acre with bramble in the background


short-tongued bees commit robbery

honey bee 'robbing' nectar

honey bee 'robbing' nectar

Bee tongue lengths vary considerably which means that some bees prefer open flowers so that their shorter tongues can more easily reach the nectar and others with longer tongues can have more exclusive access to tube-shaped flowers.

Honey bees are among those bees with shorter tongues, measuring c.6mm in length, which is still about half their body length but short by bee standards. Compare this with the 'garden' bumblebee, Bombus hortorum, with a 15mm tongue although it is a bigger bee.

Sometimes the shorter-tongued bees employ a sneaky a trick to get at nectar in deep flowers; they go to the outside base of the flower and make a hole to stick their tongues through and steal the nectar. I say 'steal' because this method bypassing the flowers pollen sources and stigmas and so the flower will not be pollinated.

I noticed this behavior and managed to capture it on some rocket that we had let go 'to seed' in the veg patch. In this case the flower petals seem to have a gap between them that allows the honey bee to get through without making a hole but the pollination is still by-passed.

rocket flowering next to the onions in our veg patch

rocket flowering next to the onions in our veg patch

Swarming season and some strange queen cells

So the bees are doing exactly what they should be doing in May if the colony is healthy; trying to swarm. Above you can see the beginnings of a 'queen cell' but its empty at this stage.

In one hive the queen excluder does not fit well and there must be too big a gap as not only had they raised up some comb but had even developed and capped several queen cells running parallel to the excluder mesh.

We have been managing our hives to try and avoid an uncontrolled swarm and have split our most vigorous colony. However, it would be very good to pick up a swarm from elsewhere as we are still one hive down from the winter and some new DNA might bring some useful options. 

Happy swarming catching!

 

Wallflowers- early colour and nectar

Native wallflower - cheiranthus cheiri self-seeded by my kitchen door

Native wallflower - cheiranthus cheiri self-seeded by my kitchen door

Wallflowers (erysimum famility formerly cheirathus) start flowering from March and some, notably 'bowles mauve' keep flowering all summer.  Their colours a range of warm tones from pinky-purples through rustic oranges and reds to bright yellows.

They are often grown almost as a single season plant; sown one year then dug up with and allowed to become semi-dry and sold as a tied bunch of tap roots to be planted in autumn or spring to provide vivid bedding flower for a year.

This method of growing provides masses of colour but is quite a lot of work. I prefer to grow them as short-lived shrub and find that if you cut them back after flowering ( or mid-season for 'bowles mauve' because it doesnt finish flowering until late) you get 3 or 4 years our of them before they get too woody to look attractive.

Some, including the native 'cheiri' - pictured above - self seed quite easily so if you are careful with our weeding the plant generates its own successors. This picture is or one that managed to seed itself into a crack in the paving just by my kitchen door and I am currently happily enjoying it everytime I go past.

For the bees, these early flowerers provide nectar and attract honey bees, bumble bees and some solitary bees; not necessarily in large numbers but over many weeks so the value is there.

erysimum 'bowles mauve' just after it started flowering in March

erysimum 'bowles mauve' just after it started flowering in March

Flowering currant; Ribes sanguineum

Bombus pratorum queen

Bombus pratorum queen

For the last two weeks (end March - early April) I have been observing the bees on a large flowering currant in my back garden mainly because, other than the daffodils, its one of the biggest sources of flower right now. It is 2 meters high and completely draped in pink blossom; quite the most magnificent display I can remember since we moved into the house 12 years ago.

Initially I was surprised at how few bees were being attracted; just the odd queen bumblebee or honey bee every few minutes, really very few for the amount of flower. Then one evening I happened to be weeding under the bush and became aware of an increased level of buzzing from above. As I stood up I was assailed with a strong perfume which i realised was coming from the bush. I had not noticed any perfume during the day so I concluded the flowering current is evening-scented and the result, of course, was that the bee numbers increased significantly.

That evening, at any one time there were 5 or 6 bumblebees and several solitary bees foraging. It was 6 o-clock so maybe a bit late for honey bees.

I cannot find anything documented about Ribes being evening-scented but that is definitely my observation. Interestingly I dont think it is night-scented which is a trait of plants that aim to attract night-flying insects and notably moths. Therefore it is this plant is aiming to attract bees that are still flying on a nice warm spring evening. Its amazing how they all manage to find their niche to compete and survive.