Synopsis : Lime, linden, basswood … a fickle source of excellent honey and a potential bee killer. When and why does the lime yield well and what explains the association of some trees with dead bees?
Introduction
There’s an early 20th Century faux castle near me with extensive ornamental gardens. These gardens – or, more accurately, the gardeners – are almost certainly responsible for the introduction of Rhododendron ponticum to the area. This is an invasive species and has spread east with the prevailing wind, blighting the environment, choking the life out of the near-unique temperate rainforest and providing me with an almost unlimited supply of firewood.
Rhododendron provide no nectar or pollen for honey bees in the UK, but are famous as the source of mad honey in Nepal. The local bumble bees do visit it, but I don’t remember seeing a honey bee on the flowers.
However, on a more positive note 1 those same gardeners also planted a row of lime trees along the road which are now a stately 30-40 metres high, in full flower and which can sometimes provide an excellent source of summer nectar.
Listen … you can hear it from here
Early on a calm July morning you can hear the insects buzzing in the canopy from at least 75 metres away … not just honey bees, but bumbles, wasps, flies, moths, butterflies and all sorts of other things as well. If we had hummingbirds here (we don’t) they’d probably visit the lime when it’s in flower.
The name ‘lime’ is derived from the Old English lind which originally referred to the lime tree, but you’ll also often find in Middle English poetry 2 to mean any tree.
Lime trees (Tilia sp.) are also often called lindens (in continental Europe) and basswood (in the US), but are unrelated to the citrus that produces lime fruit.
Lime species
There are three native or hybrid species of lime in the UK and a handful of other imported ‘exotics’, most of which I’m going to ignore (and which are only usually found in ornamental gardens):
- Broad-leaved lime (Tilia platyphyllos), is a native European tree but very scarce in the UK.
- Small-leaved lime (Tilia cordata), also native to the UK – but probably not as far North as Scotland – and mainland Europe. There’s an interesting BBC podcast on the native small-leaved lime that’s worth a listen.
- Common lime (Tilia x europaea or Tilia x vulgare) which is a natural hybrid of the broad- and small-leaved lime, occurring naturally and also widely planted in parks, gardens and often in urban environments.
To confuse matters further, some clones of common lime are fertile and can therefore further hybridise with other limes. They can therefore produce in a real melange of slightly different forms making precise identification tricky.
I’m pretty certain the trees near me are common limes. They are big trees; being a hybrid the trees grow rapidly and reach a larger overall size than the other species. They also have characteristic dense shoots at the base and middle of the tree, often making the trunk difficult to distinguish.
Shoots and leaves
Not that the precise identification really matters … all of the above, and hybrids thereof, flower when the conditions are right and provide nectar and pollen that our bees can use.
Flowering period
I usually expect to see the lime flowering in early to mid-July. Looking back through my collection of photos, almost all of those of flowering limes were taken in the first 7-10 days of July. This probably means they started flowering at the end of June or very early in July, but I only belatedly realised they were flowering later 3.
The books claim that the broad-leaved lime flowers in June, with the others starting in July. The only scientific study I could find on this was of lime in Lublin, Poland, where the flowering (of all three species) appears to be 2-3 weeks earlier than it is in the UK.
Lime flowering times in Lublin, Poland
Lime pollen is quite distinctive and its presence in environmental (air) samples over time has been used to determine the duration and peak of the lime flowering period. The majority is produced over a three week period, with the date of peak production varying by as much as a fortnight from year to year. In addition, there was considerable variation between years on the total amount of pollen produced, with ‘poor’ years producing ~25% or less than in the ‘best’ years..
Annual lime pollen levels in Lublin, Poland
In heavily treed areas it is obvious that it is only the sun-exposed parts of the lime that produce flowers. The crown of the tree in the first photograph had abundant flowers and was alive with pollinators, but the lower branches were almost devoid of the characteristic cymes (the technical term for the flowers on individual stalks) and the umbrella-like bracts which may have evolved to prevent nectar and pollen being washed away by rain.
Lime can yield well in July …
Flowers and nectar
The common lime produces the most profuse flowers, ~30,000, which is about three times the amount produced by the broad- or small-leaved lime (Jacquemart et al., 2018). These figures were per cubic metre of tree. Remember that the hybrid common lime often forms a significantly larger tree, so a large one at the peak of the flowering season will produce a massive amount of flowers … explaining my ability to ‘hear’ the tree from down the hill on a calm morning.
I specifically say ‘morning’ because nectar production tails off during the day and is at its highest in the morning.
Although the common lime might produce more flowers, it produces only half the amount of nectar per flower than the small-leaved lime. On average, each flower of common lime produces 0.75 μl of nectar. One microlitre is one millionth of a litre, so a large tree bearing 30,000 flowers per cubic metre is going to be producing litres of nectar at any one time.
Nectar sugar content at the genus level – Tilia starred
The sheer volume of flowers, coupled with their accessibility and that of the nectar (no long tongues needed here), more than compensates for the relatively low sugar content of lime nectar (~35%).
Rain
In reading half a dozen scientific papers on Tilia I didn’t see a single reference to rainfall linked with comments on nectar production and/or flowering of lime trees.
Which is a bit odd because almost every beekeeper who claims to know anything about lime will say something like ’they need a bit of rain to yield well’ …
For example, yesterday morning my friends at Kilbarchan and District BKA posted the Tweet above.
Which, considering the weather we’ve had recently, made me think … how much rain is needed and when is it needed for lime to yield well?
All of the figures I’ve quoted above make no reference to the climatic conditions in the days and weeks preceding the measurements being taken.
Was 2005 a particularly dry season in Lublin?
Did the rain arrive at just the right time in 2006 for the pollen count (and therefore the flowers that produced the pollen and, presumably, the nectar that attracts the pollinators to the flower) to be so high?
If so, when was ‘just the right time’?
I checked Hooper’s Guide to Bees and Honey which barely mentions lime. Hooper claims he’d seen no good crops of lime honey since the 1930’s. Manley’s Honey Farming only has a couple of sentences on lime. Both, directly or indirectly, suggest that lime isn’t a dependable nectar source.
I don’t have an extensive library of beekeeping books, and have relatively few older books, so there may well be something published I’m totally unaware of that explains the need for 100 mm of rain in the 3 weeks before the onset of flowering.
Or is the entire ’lime needs rain’ thing a convoluted excuse dreamt up by beekeepers to explain the lack of a good summer honey crop?
Rain this season
Late May and the first three weeks of June this year were dry and hot on the west coast. I know the lime are flowering and that the trees are hoachin with pollinators, including my bees. Perhaps the conditions have been ideal?
Here, for reference as much an anything else, are graphs of the rainfall and mean and maximum temperature since the 1st of May (or do I need to go further back?).
Temperature and rainfall
Unfortunately it’s unlikely to be a bonanza lime honey crop here on the west coast. Firstly I think there are too few trees and, being in a heavily wooded area, only the canopy really flowers well. Secondly it’s been 12°C most of today and raining hard 🙁 .
Lime honey
Lime honey is considered a premium honey … at least by me 4. It’s a clear, runny honey, and is often a light golden colour. Darker lime honey almost certainly also contains honeydew derived from the aphids that are busy feasting on the lime trees.
The honey often has a faint greenish tinge when freshly extracted and jarred.
You’ll read all sorts of descriptions of the aroma of lime honey … I looked up a few online and they read like a contribution to Private Eye’s Pseuds corner.
woody, pharmacy and fresh
mint, balsamic, menthol and camphor
sweet violets
mouth-watering citrus fruit flavour and tantalising notes of fresh mint
The one word I most associate with the flavour of lime honey is zesty. To my jaded palate it tastes deliciously fresh and not too sweet.
In my experience it sells very well, with lots of repeat orders … ’could I have another half dozen jars of that last batch?’
Lime leaf
But, unfortunately, in agreement with Hooper and Manley, it does seem far from dependable. Over the last 15 years I think I’ve only had three or four seasons where the lime has yielded well enough to generate significant amounts of essentially monofloral lime honey, though I’m sure it features most years in the mixed summer blossom honey 5.
This variation must be environmental as the trees are a fixture, in contrast to crops like OSR or field beans which vary from year to year.
Of course, being environmental, there’s nothing much I can do to change the temperature, rainfall or humidity … but it would be good to understand what is needed to create a great season for lime honey.
Lime trees and bee deaths
Lime, particularly non-native species and the hybrid common lime, are often planted in towns and cities. They are relatively resistant to pollution and – other than the drip, drip, drip of honeydew – well suited to an urban environment.
There are numerous reports of dead bees – both honey bees and bumble bees – underneath flowering lime trees. These go back centuries (Koch and Stevenson, 2017 cite Bock, H Kreüter buch from 1551 which I can neither source or read 😉 ) and includes an article in Bee World by Eva Crane (1977) that attributes these deaths to mannose sugars in lime nectar.
The species most often associated with bee deaths is the silver lime (Tilia tomentosa), native to south-eastern Europe and south-western Asia, but which is grown as ornamental tree in the UK.
The previously cited Koch and Stevenson (2017) consider five potential causes of these bee deaths:
- Toxic metabolites e.g. mannose or nicotine
- Insecticides
- Natural causes/old age
- Starvation
- Chemical deception
Despite Eve Crane’s assertion that mannose is responsible, several independent scientific analyses of Tilia nectar show it contains no mannose. Since bee deaths date back to Medieval times we can probably rule out insecticides. The natural causes/old age is likely refuted by the age of the corpses, most of which are not decrepit old bees.
The last two potential causes are partially linked.
Most bee deaths are associated with the end of the T. tomentosa flowering period and the suggestion is that the depleted nectar resources leads to starvation. Foragers have depleted sugar reserves and can be ‘rescued’ by being fed Tilia nectar. The chemical deception theory suggests that volatiles in the nectar (e.g. caffeine) cause persistent foraging even after nectar is depleted, again leading to eventual starvation.
Koch and Stevenson (2017) propose that starvation causes these excess bee deaths.
Tilia nectar analysis
A little more recently Jacquemart et al., (2018) conducted a detailed analysis of nectar from T. tomentosa and from the three UK species listed above.
None of the nectars contained detectable levels of mannose or nicotine. I think this pretty much excludes these as the cause of the dead bees seen under lime trees. Bumble bees – which always outnumber honey bees when the corpses are counted – fed either T. tomentosa or T. cordata (small-leaved lime) nectar showed similar levels of survival to controls.
Smell the coffee …
Whilst I think we can rule out toxicity and insecticides as the cause of the bee deaths, I’m not entirely convinced that simple starvation is the cause.
Bramble
There are other nectars available when the lime is flowering (and going over) – for example, blackberry is looking great at the moment – so you would have to argue that the loss of a major nectar source (probably the largest single nectar source in an urban environment) was associated with a constancy that prevented the switching and exploitation of other nectars.
Constancy is defined as ‘restricting visits to one flower type, even when other rewards are accessible’.
This is where the chemical deception theory originates.
Perhaps there is something in Tilia honey that effectively deceives bees to continue to return to the lime trees after nectar stops being available? 6
One suggestion is that small amounts of caffeine in Tilia honey are responsible.
Constancy? … you bet
Coffee and bees deserves a full post of its own … there is evidence that caffeine increases foraging and recruitment, but these studies are on honey bees. I’m not sure similar studies have been conducted on bumble bees which account for 75% of the dead bees.
Finally, to confound the story further, honey and bumble bees differ in their natural (decaffeinated) constancy, with the former showing significantly greater fidelity.
I think our understanding of the association of Tilia foraging and bee deaths remains incomplete. Although largely involving the silver lime, other species have been implicated as well.
In the meantime, I’d just like the weather to improve so that my bees can take advantage of the row of huge flowering limes just down the road …
Notes
Two final thoughts that came to me just before posting …
- lime may not have evolved to ‘deliberately’ (which isn’t how evolution works) deceive bees into elevated constancy and subsequent starvation. The caffeine (or whatever) that deceives bees might be a secondary product of the tree, unrelated to bees and pollination.
- are lime more often associated with bee deaths than other large nectar sources? How many dead bees have been counted in a field of oil seed rape? Lime are often planted in urban environments where, a) they are easily accessed by bee-aware members of the public, and b) the ground under the tree is usually flat and either tarmac or closely mown, rather than dense understorey and ground cover in natural woodland.
References
Crane, E. (1977) On the scientific front. Bee World 58: 129–130 https://doi.org/10.1080/0005772X.1977.11097662. Accessed July 6, 2023.
Jacquemart, A.-L., Moquet, L., Ouvrard, P., Quetin-Leclercq, J., Hérent, M.-F., and Quinet, M. (2018) Tilia trees: toxic or valuable resources for pollinators? Apidologie 49: 538–550 https://doi.org/10.1007/s13592-018-0581-3. Accessed July 4, 2023.
Koch, H., and Stevenson, P.C. (2017) Do linden trees kill bees? Reviewing the causes of bee deaths on silver linden (Tilia tomentosa). Biology Letters 13: 20170484 https://royalsocietypublishing.org/doi/10.1098/rsbl.2017.0484. Accessed July 4, 2023.
Weryszko-Chmielewska, E., and Sadowska, D. (2010) The phenology of flowering and pollen release in four species of linden (Tilia L.). Journal of Apicultural Science 54: 99–108.
Footnotes
- Other than the savings on firewood which would otherwise cost me £160 a bag.
- If you read Middle English poetry.
- I’m a bit slow off the mark
sometimesoften. - Your preference may be different.
- I know there are trees well within foraging range over this period.
- Though I’m struggling to think of an evolutionary justification for this.
David
Last summer we had a bumper lime tree honey crop. Supers just filled with the delicious pale zesty honey. This season there appeared to be a prodigious quantity of line blossom – probably a legacy of the previous hot summer. Anticipating another bumper nectar harvest I banged extra supers on – sadly the nectar flow didn’t materialise and I have removed the additional supers this week to help concentrate the remaining honey.
The book “Plants for Bees” by W D J Kirk and F N Howes has three pages devoted to lime trees. It states that there is no apparent correlation between weather conditions and the nectar yield. But as you say – there’s little we beekeepers can do about the lime tree nectar yield- enjoy it when it flows and hope that the bramble and other sources compensate.
Hello John
Thanks for the pointer to Kirk & Howes … and the comment about the lack of a link to weather. I wonder why so many beekeepers consider ‘enough rain’ is important? I guess if you hear it from an old-timer and then get no lime honey it’s a convenient explanation.
Last summer the lime on the west coast was worse than useless – too much water – with over 270 mm of rain in June and July. We’ll see how things go this year, but June was much drier.
Cheers
David
The forerunner to Kirk and Howes book is the original “Plants and Beekeeping” by Dr FN Howes who was a professional botanist and one of the scientific staff at Kew. He devotes 8 pages to Lime including a flowering graph. The original book was written in 1945 and revised in 1979. It’s out of print but often avilable on ebay and such-like.
Many thanks Adam
Some of these ageing botany books are going to have to be read with a guide to global warming by your side. The current evidence suggests that dates are ~5 days earlier for every decade. I’ve got a part-written post on this for sometime in the future (when and if I get any time 😉 ).
Cheers
David
Many thanks for your analysis David. For the last 20 years my apiary has been adjacent to a row of 13 limes. They were probably planted (species unknown) 30-40 years ago and have doubled in size in my time. They flower in late June.
I never know if they’re yielding because the plentiful blackberry nearby flowers at the same time (sadly I’m incapable of detecting ‘tantalising notes of fresh mint’……). Nearly always I’m disappointed that I can’t hear a buzz as I stand beneath them. There seem to be few bees visiting – bumbles are more common.
Hi Giles
The ‘zesty’ flavour of lime honey is really quite distinctive, even as a mix, so it suggests your trees are ignored and/or not prolific nectar producers. Nothing wrong with lots of blackberry though 😉 On the morning I could ‘hear’ the lime down the road the nearby blackberry – which are in full flower – was being ignored. Bees are very good at making qualitative judgements of the best source of nectar and adjust their foraging accordingly.
Cheers
David
Once again David – a lovely article and one that I, as most beekeepers and honey extractors, particularly enjoyed.
The one thing that interestingly you haven’t included in your survey of the topic is that somewhere built into my 60 years of beek keeping I learnt, and that is always a dangerous term as it does depend on the reliability of the information, that the air temperature needs to be in the 70’s Fahrenheit (nominally 20+C) to get the nectar flow going.
I was aware of rain, but that is related to the lime trees all being shallow rooted – at least again that is what my ‘knowledge’ says – and hence a dry summer may be warm but there’s no water at the roots to get a nectar flow going.
I remember a short holiday at Tomich near Cannich where the sound of insects in the lime avenue there was just so very apparant.
And as for flavour – whenever I have ever had it in the West Lothian area on a nominal 10 year cycle, I’ve detected spearmint rather than mint, but then quite a lot of mint now is the former so that’s a further confusion.
Cheers
Rob
Hello Robert
Forestry England claims that the small leaved lime (no other species mentioned) is deep rooted and so considered a soil improver. It might be the latter without being the former of course … and a quick search turned up nothing on either of the other two species common to the UK. The USDA helpfully records that the minimum root depth of basswood (Tilia americana) is 30 inches … but have no mention of the maximum. Cetainly your comment about water needs and root depth make sense.
I’m not sure what to make of the reported need for temperatures of over 20°C for nectar (or whether that’s to get it to start, or to flow at all?). On the first day I noticed the trees near here alive with pollinators it was definitely under 20°C, though not by more than a degree or two. Since then we’ve had wind, rain and low temperatures … until this morning when it’s warm again. I’ll be checking later this morning and my bees were already very busy at 8 am 🙂
Cheers
David
“In the meantime, I’d just like the weather to improve so that my bees can take advantage of the row of huge flowering limes just down the road …”
Ditto.
I live near (quarter of a mile) to Biddulph Grange Gardens – a National Trust Property – which has a “Lime Walk” of approx 40 limes plus more in the adjoining cemetery. Last years’s late summer honey # had a rare tangy flavour which I attributed to lime. I hope for more.
I extract Spring Honey, Early summer honey and Summer honey. Basically to relieve the pain of extracting, bottling and labelling and also to SELL in advance of my competitors . (It works)
Want relief from hay fever? My customers swear it works! I say “my customers say it works but I don’t guarantee or claim anything!”
Hello Michael
‘The customer is always right’ 😉 … though the science suggests that the alleviation of hay fever is not something honey does. However, even if that link is wrong, it’s a delicious mistake to make.
My recollection is that lime honey has a relatively low pollen content overall (can’t remember why) and that you don’t need to find a lot of lime pollen in honey for it to be designated as lime honey. I’m not certain of this and don’t have a microscope for pollen analysis so can’t test this (at the moment).
Cheers
David
about time the myth created by Eva Crane was put into context with more up-to-date evidence; thanks David. even the BBKA special edition on honey talks about the evil mannose.
An interesting paper by the Brussels’ council, who planted a lot of lime trees, goes into a lot of detail. For those who don’t read double Dutch it still provides a helpful list of various references:
https://www.vlaanderen.be/inbo/publicaties/advies-met-betrekking-tot-massale-insectensterfte-onder-zilverlinde-tilia-tomentosa-en-de-geschiktheid-van-deze-uitheemse-soort-als-laanboom-in-het-brussels-hoofdstedelijk-gewest
Hello Hans
There’s quite a lot in the literature disproving the mannose toxicity of lime nectar. It’s interesting how some ‘facts’ linger on despite overwhelming evidence to the contrary.
Thanks for the link. I ran it through Google translate. It’s not perfect (not because my Dutch is good, but because there are a few oddities in the translation!) but it makes interesting reading. Here’s a copy in English for those who don’t read Dutch. Aside from the mannose it makes two other interesting and relevant points – the first is that the dead bees, despite there being apparently large numbers, probably make little or no impact on the overall decline of bees as the numbers are rather small in the overall scheme of things. Secondly, they have some numbers for the yield of nectar and pollen from lime – in 10’s to 100’s of kilograms per hectare per year.
Cheers
David
Lime – about 3-years ago we chatted about the taste of honey and it’s complexity when produced from botanical rich cities like Vancouver. You then mentioned Lime trees and the prized honey it can yield. Not knowing I have done some research – there are 6,621 lime trees on our streets and boulevards with 102 west of our place. They are just now in bloom but little rain. To my east another 245 trees but few bees leave the apiary in that direction. In May I stumbled on a property with 3 enormous Black Locust trees. The fragrance 2x the intensity of Lime. Both incredibly lovely. That made me think our spring honey was heavily influenced by locust and even more so than the later blooming lime. Our tree data base has only just over 100 locust trees on streets but once I targetted the look of black Locust in bloom we have hundreds if not more locally without beautiful tree just a few blocks west. Black locust here is considered invasive due to its aggressive ability to occupy sunny cleared spaces. Both amazing trees. Next year I’ll try to place a few hives at the doorsteps of some good rows of each.
Hello Vince
Your town is very well documented 😉 … some of those I’ve lived in weren’t even completely mapped, let alone having a count/location of the trees present. Some of our town councils seem more interested in cutting trees down than cataloguing what’s there and how it might benefit the environment.
Lime is definitely a summer honey here and I’d be surprised if there was any ripe honey for extraction before the middle of July. As I said in an earlier comment, I’m not aware of Black Locust (false acacia here) being a notable source of nectar, though that might simply reflect a shortage of trees rather than the fact that those that are here don’t produce sufficient nectar.
Cheers
David
Thanks for this interesting post, all of which was new to me. I will now go and have a closer look at the lime trees near my apiary! I had one year of lime honey which was very light and so different from other honeys I had tasted. Now I know why:)
Hi Becky
Now all you need to do is work out which year, refer back to your notes on the weather, wait for the conditions to be repeated and prepare yourself for another bumper crop of lime honey. Or – like most of us – simply hope that it’s this year 😉
Cheers
David
Hello Limey
Your excellent article prompted me to go and inspect the limes I planted in the garden alongside oak (common), approx 18 years ago, when they were mere bare rootlets
I had forgotten which variety of lime I had chosen. On inspection they are tilia cordata, they’re growing only slightly faster than the adjacent oak, so they’re not showing the vigour of the common lime. The undersides of the leaves have have tufts of rust coloured hairs where the veins branch which clinches the identification
Today the flower buds are tiny, tight and immature but I now read that the small leaved lime flowers late July, well after the commoners. I would walk the half mile to see what variety the huge roadside limes are, but it’s now raining. Those limes will have lovely wet feet, whatever their provenance
Hi Ivan
Many of the roadside and avenues of limes appear to be common in my experience. The BBC podcast referred to in the post has quite a bit of history and natural history on the small-leaved lime – naturally absent from both the north and the west it seems.
You should be ideally placed to determine what conditions are needed for nectar production … perhaps report back in a decade or two once things are a bit clearer 😉
Cheers
David
I keep bees in the Scottish Borders and lime is the main and in my experience a reliable source of July nectar. It’s deep rooted and doesn’t rely on rainfall entirely. ( tho I saw some trees near Ayr recently that were obviously suffering from drought, but were flowering profusely (nectar?). One plus point is that there seems to be some genetic diversity amongst trees in our area and they all come into flower at slightly different times.
Hello James
I think the hybridisation between species and then between hybrids and named species and different hybrids all contributes to that variety. Selecting an apiary within range of a suitable number and diversity of hybrids might provide nectar over a month or more.
I’ll be checking some of the limes near my Fife apiaries tomorrow and Monday. In a good year they have been very productive in the past.
Cheers
David
There is a copy of the Kreuter Buch from 1551 available online at this link – https://www.google.co.uk/books/edition/Kreuter_Buch/1KZlAAAAcAAJ?hl=en&gbpv=1&dq=Bock,+H+Kreüter+buch&printsec=frontcover but unfortunately my German is not good enough to translate it. (And posting the link does not mean I expect you to either!)
That aside, here is Suffolk, there has been a lot of chatter about whether the nectar will flow. The pollen appears plentiful as our bees are bringing in stuffed pollen sacks of the right colour to suggest they have found it. Fingers crossed.
Hello Sal
Thank you for the link … very interesting, but not something I’ll have a go at translating 😉 I did a quick look for linden (or linde as I think it was in the 16th Century) and it’s in the index, but I couldn’t then find the relevant page (partly because they’re numbered in Latin, and partly because some of the numbers appear not to have scanned.
Looks as though the lime won’t be giving us much here on the west coast as the trees were pretty quiet this afternoon (in full sun, 21°C, but a drying breeze). It’s notable that honey bees appear to be the first to abandon it as there were still a few wasps and bumble bees in attendance.
Cheers
David
Very interesting, as always. Thanks David
In ‘Honey Production’ by Manley, and FN Howes ‘Plants and Beekeeping’ they both mention the need for warm sultry nights and mornings (Howes) and high temp and humidity (Manley) for the nectar to flow well. Howes also states optimum temperatures in Europe considered for lime nectar secretion to be 66 F to 70 F (18-21 C) quoting Bee World 1938, 29. Its not clear whether this is the nocturnal temp. though as I don’t have the Bee World ref.
Hi Amanda
Interesting, thank you. The best lime honey crop I’ve had was from Fife where we rarely got anything like night temperatures of 18-21°C (or warm, sultry nights). However, that’s not to say that the same trees in Hampshire wouldn’t have yielded a darn sight better!
The 1938 volume of Bee World appears to be 19 (not 29) … but I don’t have access either.
Cheers
David
David, apologies for a late reply – I have been away and only just caught up with my reading.
We have an avenue of about 50 Tilia cordata along our driveway , planted by the local council around 25 years ago. We have had rather few bumper years of lime honey and they seem to relate to having still conditions (not windy), sunshine and reasonable rainfall in the months prior to flowering. I regret I have not kept records so just my memory. Compared to blackberry it is not reliable forage but in the occasional year a great bonus. Sadly it is not predictable until the bees start to bring in the nectar.
Hi Michael
Interesting, thank you. I suspect the combination of variable moisture, wind and sun means it would take 25 years of record keeping to detect a pattern. When it yields well it’s wonderful … I just wished it happened a little more regularly 😉
Cheers
David