Organic Growers of Fairlie

By Nancy McQueen

Organic Growers of Fairlie is a sustainable community garden with space to grow vegetable and fruit both outside and in polytunnels. We hold workshops and events that everyone can take part in and have established woodland and forest walks. This is now a super rich area for wildlife and a sheltered quiet spot for those wishing the tranquility and peace that a woodland can offer.  This is how Keep Scotland Beautiful sees our garden.

We are rewarded with a multitude of pollinators such as bees, butterflies, moths and hoverfles. There are also many sightings of voles, frogs, bats and hedgehogs which all benefit from the natural environment created by sustainably planting for people with the environment in mind. These are a multitude of natural pest controllers.

This environment has been created over many years by enthusiastic gardeners and volunteers.

The previously derelict site was historically a train yard, and also used for boat repairs.  Contaminants were found in the soil when we first started gardening here fourteen years ago.  The three acre site was also one third covered with Japanese knotweed.  

We were instructed not to walk on the soil and were not able to grow anything  edible  in it either. It was necessary to grow in raised beds and make our own compost or buy it in.  The whole site was covered in wood chip, donated by tree surgeons, and it quickly composted into good soil of a great depth. The site was cleared of Japanese knotweed mainly by persistent and careful hand removal. A grant from Scottish Natural Heritage of £10,000 was helpful in starting the allotment, however our main funders were Hunterston PowerStation, and we were one of the first to receive a grant from The Climate Challenge Fund.

Local children planted many native trees we received from the Woodland Trust along the garden edges, and wood chip was put down to create a woodland nature trail along the perimeters.  A shelter belt of native trees was planted at the front of the garden.  We now have a small woodland at the back we are developing which contains a tree nursery. It was here we released adopted hedgehogs from a wildlife rescue centre. Now after fourteen years the trees are maturing well. There is also a local area we are developing as a community woodland.  

Our gardeners conserve rainwater with water drainage from our roof into bowsers and make organic compost using our own vegetable remains.  Fifteen to twenty tons is produced a year. Two hot bins produce compost as well as a liquid feed.  We have members who are making compost and worm-tea using composting worms and wormeries.  Young gardeners are being mentored in composting and maintaining wormeries as well as other gardening and environmental skills. They work on a ‘Grow and Learn’ Award from The Caley.  Knowledge gained is shared with anyone interested or other groups. We have had groups of youngsters achieve the John Muir Award.

Comfrey is grown for plant feed. Leaf mould and seaweed are used as mulch. It is a coastal garden. Recycled coffee grounds and rock dust help revitalise the soil.  These are all activities  which benefit the environment and encourage the pollinators needed for growing our crops.

We have bat and bird boxes in the garden and bug hotels and bats are seen in the early evening. A bat viewing night was held.  Our pollinating plants are many and have been chosen to attract pollinators throughout the seasons. Crocus bulbs in the spring, pot marigolds in the summer and ivy in the autumn/winter are a few of these.  Clover which attracts many bees is left while mowing the grass. Long grass is kept in some areas for natural habit.  Many nettles for butterflies to lay their eggs are retained. Night scented stock and evening primrose are grown to attract insects for bats to feed on as well.

We are involved in other projects where we have planted for pollinators throughout our village including Fairlie Station garden, two small picnic areas, a green space play area where soft fruits, apple trees and mints are grown for community use. A volunteer from our group improves an area in a neighbouring village as well. One volunteers has established community seating area with attractive planting. Young people have been involved in growing plants for many of these areas such as borage and planting them with wildflower seed which they maintain as well. 

These areas have beautiful wildflower displays which everyone enjoys. We have handed out 40 packets of wildflower seed this past year to encourage a pollinator trail in the village and also about 50 wildflower seed bombs to youngster. The local primary school and the garden co-operate with projects such as making seed bombs and nature surveys. Citizen science surveys have taken place on our site, and we also created a small pond in the garden. 

Our polytunnels are filled with marigolds and nasturtiums to attract pollinators but they also attract birds that feed on them.  A wren was found nesting under a lettuce leaf with a cluster of eggs so we need to be careful.  Most members are so pleased they forgo their gardening until the chicks have fledged. Nesting in the polytunnels is a regular occurrence in the spring.

Two members began to create a wildflower meadow at the front of our garden about four years ago in a grassy area of poor soil. Some plants such a rattle where grown from seed and planted as plugs to get established.

The area has matured over the years and has long attractive grasses interspersed with splashes of colourful plants such as thistles, vetches, vipers bugloss, oxeye daisy, lady’s bedstraw, trefoil and queen of the meadow and more.  Multitudes of bees are found feeding during the summer and butterflies such as the common blue.  

Goldfinches feed on the thistle seeds and other birds which eat small insects are regular visitors.  Ground beetles hide in the grass during the day and feed on slugs and flatworm which is an invasive species in the garden.  Pipistrelle bats eat moths and midges at night.  Frogs use the meadow as a shelter and eat slugs.  Hedgehogs use the meadow to pass through.  

Wildflower seeds are collected in the autumn for next years planting and the meadow grass is cut back in the autumn. There are recycled boxes where we plant wildflower seeds. The biggest challenge in 2021 for gardeners was three months of hot weather without rain. The tiny wildflower seedlings in boxes needed constant watering to thrive which volunteers did regularly.  

In the future we would like to work with the council to have dedicated wood ‘bee boxes’ filled with compost for growing wildflowers in areas in the village where ground planting isn’t possible. We would also like to help the Primary School with a dedicated area for wildflowers. We’ve come a long way in 14 years, and we have ambitions to do much more yet.

The ‘Whomping willow’ and golden pollen

Perhaps the most famous willow in literature is the one which appears in JK Rowling’s Harry Potter stories. However, the ‘Whomping Willow’ isn’t the only magical willow, away from the pages of novels the real-life goat willow could be described as pretty impressive too, especially when it comes to pollinators.

Male catkins covered in pollen rich anthers

There are few sights in nature as captivating as the golden male catkins of the goat willow. And the early flowering catkins are more than simply attractive to look at; they are a huge bonus for bees in very early spring when sources of pollen and nectar are scarce. The golden colour of the male catkins is down to pure pollen. Before the gold colour appears the catkins will look grey or even slightly pinky-orange.  The catkins have lots of individual flowers, each one with a tiny blackish leaf-like scale.  These minute catkin scales develop lots of grey hairs at their tips making the whole catkin appear furry, protection from the biting cold wind.  If you want to see early pollinators then park yourself near a flowering willow, for hungry pollinators rarely resist them. 

Willows are interesting trees. The goat willow (also known along with other willows as pussy willow) is large for a Scottish willow.  It is said in some quarters that there are 400 or so species of willow, and they come in all shapes and sizes such is the ability of the willow to generate cross breeds. In Scotland alone a list of trees and shrubs native to these shores would include grey willow, dark-leaved willow, tea-leaved willow, and bay willow. Scotland’s smallest tree is the dwarf willow, about 5cm or less in height and found hugging the ground on some of our most exposed mountains.

Around the Ben Lawers area, local bee expert Anthony McCluskey (who many of you will know in his Butterfly Conservation role) studied a restored woodland area, with plenty of willow, to see what insects were foraging on the catkins. He found several mining bees including the stunning Clarke’s mining bee and his Glen Lyon records broke new ground for the species. 

Just as species range can change so the uses we make of natural resources alters too. Times change and the wood of the willow isn’t particularly valued these days, but in earlier times it was used to make a diverse range of goods including handles for hatchets, baskets, peat and lobster creels, and the humble clothes peg. For many willow is synonymous with cricket bats. Indeed the phrase ‘leather on willow’ came to encapsulate the height of English summer, with the sound of a cricket ball being whacked with a willow bat ringing out on village greens up and down the nation. 

Tree bumblebee feeding on catkins

There was also a time when the willow had greater aesthetic appeal. Many Scottish families will recall a time when their family used to cut pussy willows to put in a vase of water with daffodils.  The name too conjures up the famous Wind in the Willows, beloved of children and adults now for several generations.

Salix caprea, to give the goat willow its ‘Sunday’ name, with careful coppicing can remain a ‘shrub’. But turn your back for any length of time and you may indeed have a ‘Whomping willow’ on your hands. With many stems this is a plant that can gallop to heights of around 15 metres if left unchecked.

The catkins are fascinating because a willow can produced either all male or all female catkins, but never both together on the same tree. We now know that willows are dioecious, that is the plants are either male or female, and we appreciate too that they are pollinated by the wind. Indeed despite considerable interest in the gathering hordes of pollinators in spring the key pollination time for the goat willow is actually late winter or perhaps very early spring, and usually in advance of the distinctive oval leaves showing on the tree. 

There is yet more to the willow (which can live for up to 300 years) than feeding early emerging pollinators.

The glossy green leaves act as a source of food for the larvae of several species of butterfly and moth, including in the south of England the impressive Purple Emperor. Closer to home it is worth looking out for the sallow kitten or puss moth. These are both extremely furry moths, with impressive caterpillars. The former is interesting because it is one of the species that has two generations a year in the south of its range, and only one in the north, including northern Scotland. They both feed on poplars as well as willows – the two genera are closely related and quite a number of species use both. Our native poplar, aspen, flowers quite rarely in Scotland, so it’s less useful for pollinators, although it still supports a lot of insects that use other parts of the tree.

Few would deny that it is the bright yellow blooming catkins which are the star of the show attracting honey bees, bumblebees and solitary bees in good numbers. It’s worth keeping an eye out for willow and their eye-catching catkins. If there are any pollinators around you won’t be the only one impressed. This is one tree that can cast a magical spell in early spring.

Northern star

They are busy folk at the Bumblebee Conservation Trust. Their mission may sound deceptively simple –  to increase the number and distribution of bumblebees – but they are astute enough to know that  you need many tools and heaps of energy to deliver such a critical ambition.

Their partnership with Scottish and Southern Energy Networks in the northern reaches of Scotland is a point in case. When the energy company looked, in 2017, to improve the area around their Thurso South substation for wildlife they sensibly sought out the Bumblebee Conservation Trust. The result was a highly productive partnership which resulted in a sizeable and well-thought out meadow.

That meadow was one step along the route to helping bumblebees in the north of Scotland. It was a well-designed project. A tailored pollinator seed mix, in harmony with the local conditions, was put to good use and surveys in 2018 and 2019 confirmed that insects were quickly using the site. In 2020 came the great news that the Great Yellow bumblebee had been spotted using the site.

The first Great Yellow bumblebee recorded at Thurso south substation meadow, August 2020.
Image (C) Katy Malone, BBCT.

The Great Yellow bumblebee was once widespread throughout the United Kingdom, but is now only found in a handful of areas, all of them here in Scotland –  Caithness, north-west Sutherland, the Hebrides and Orkney.  It is one of our rarest bumblebees, needing extensive meadows and particular types of habitats, such as machair, to survive from year-to-year. 

Twelve months on from that individual 2020 sighting the regular visits of a local volunteer established conclusively good numbers of Great Yellows using the site. And there was yet more good news when the Bumblebee Conservation Trust staff visiting in August 2021, during a research trip, were rewarded with a view of more than one queen bumblebees making the most of the Thurso resource. It’s not a quantum leap from there to surmise that the species is probably nesting on the site.

The success in Thurso helps illustrate progress and makes it easier to engage with the general public and landowners in a bid to inform future conservation of this species.

The Bumblebee Conservation Trust provides tailored advice to farms and landholdings to support beneficial management of sites for Great Yellow bumblebee through the Saving the Great Yellow Bumblebee project which as been running since 2019. New projects are always in the pipeline to carry forward this work and expand it even further. They provide follow-up support to farmers, landowners and agents across high priority Great Yellow areas and, where appropriate, advice on management options funded by SRDP-AECS (Scottish Rural Development Programme, Agri-Environment Climate Scheme). This advice is highly tailored to each site, ranging from suggesting suitable voluntary measures to adopt, through to helping with written letters of endorsement.

One element has been to employ survey consultants to gather data on forage and conduct bee surveys along the north coast of Sutherland, and the Outer Hebrides, in June through to early September. The intention is that these reports will highlight suitable areas to target more intensive surveys for Great Yellow bumblebees in the areas, record the quality of forage across the landscape, and suggests where a change in management might help encourage better habitats for this rare bumblebee. Another strand is looking at the genetic variability in Great Yellow populations to find whether genetic relatedness is increasing – this would affect the long term viability of these remote populations and help the Bumblebee Conservation Trust work out new approaches to conservation.

Conservation Officer (Scotland) Katy Malone is delighted to see these different threads coming together in a coherent drive to address the challenges facing the Great Yellow bumblebee. “We’ve made great steps forward in helping this iconic species thrive in new areas, but there is still so much work to do. Only with the help of our supporters, members and volunteers, and in partnership with business and conservation organisations, can we sustain this effort and see bumblebees thriving again across our landscapes. We need to deliver across entire landscapes from the Outer Hebrides right up to Orkney. I’m really excited to be a part of the development of new projects which will help us establish even more sustainable solutions.”

Trust staff finding Great yellow bumblebees at SSE Thurso south substation in 2021 during a research trip. Image (C) Katy Malone, BBCT.

Founded in 2006 and with almost 8,000 members, the Bumblebee Conservation Trust has a level of specialist knowledge, active nationwide groups and targeted projects that makes them a key partner in successfully delivering the Pollinator Strategy for Scotland. 

They work on a range of projects simultaneously, ranging from research and monitoring, through public engagement and information services, to leading effective campaigns. If you want to find out more then settle down in front of their website. It’s a fantastic resource to not only gain in insight into their projects, but find all sorts of practical and easy to follow advice on how to help bumblebees. Their ‘Bee Kind’ section is just one example featuring planting recommendations to enable us all to do our bit to help bumblebees and other pollinators.  

There is no doubting the Bumblebee Conservation Trust are busy, but equally there is no doubting their relentless focus in the battle to tackle the many challenges facing our native bumblebees. What’s going on in the north of Scotland is just one fine example.

Find out more:

The Bumblebee Conservation Trust website

Bumblebee Conservation Trust 2021 cash appeal

Bumblebee Conservation Trust gift membership

The writing on the pollen

By Athayde Tonhasca

Palynology, from the Greek palynō (‘sprinkle’), is the study of microscopic organic particles such as spores, planktonic organisms and pollen. The branch of palynology focussed on pollen contained in honey is called melissopalynology – the ‘melisso’ part refers to bees, from the Greek mélissa for ‘bee’. This tongue-twister sounds as arid and academic as a study subject could be, but this is not the case. By examining the pollen in a sample of honey, it is possible to determine its purity, geographical location and floral sources. Melissopalynology is a tool to combat fraud and inaccurate labelling of honey, which is handy if you want to buy pure Elvish honey from Turkey, Manuka honey from New Zealand, or other expensive honey bee products. 

Morphology of different pollen from honey samples © Obigba, S.O. 2021. IntechOpen 10.5772/intechopen.97755

Melissopalynology has other applications. It can be used to assess climatic conditions such as rainfall and temperature at the honey’s place of origin, or tell us about environmental changes. This is particularly useful in light of the rapid losses of natural habitats around the world, mostly because of agricultural expansion and intensification.

Half of the world’s habitable land is used for agriculture © OurWorldinData.org

By comparing pollen in honey samples from 1952 and 2017, researchers recorded a profound shift in the most important flower sources for honey bees in the UK. White clover (Trifolium repens) was present in 74% of the 1954 honey samples, but it decreased to about 30% in 2017. Brambles (Rubus fruticosus agg.) and related species were found in 5% of the 1954 samples, but in 2017 they became the most foraged plants.

Predominant and secondary honey bee pollen sources in 1952 (left) and 2017 © Jones, L. et al. 2021. Communications Biology 4, 37

These changes in honey bee preferences have reasons: with the intensification of managed grasslands, crop rotation decreased, and the use of fertilizers and herbicides increased. So clovers became less abundant; countryside surveys revealed a 13% decrease of white clover distribution from 1978 to 2007. Changes in the rural landscape favoured opportunists like brambles and invasive species such as Himalayan balsam (Impatiens glandulifera) (a great source of nectar), which increased their distributions from 1978 to 2007 by 21 and 100%, respectively.

A change of main course for honey bees; from white clover (L) to brambles © Harry Rose (L) and H. Zell, Wikipedia Creative Commons

A shift in sources of food may not sound too bad; honey bees still have their flowers. But not all flowers are equal: brambles have lower levels of proteins and essential amino acids than white clover. Honey bees may compensate for this nutritional deficit, but that requires more time and energy spent on foraging.

Pollen is the main source of proteins, fat, minerals and vitamins for honey bees and many other pollinators. But it is also a rich source of information: pollen attached to museum specimens has helped us understand changes in the distribution and abundance of bumble bees and other pollinators. Taxonomists, earth scientists, climatologists, archaeologists, palaeontologists, and criminal investigators – those examining suspect honey, or those tracing a body, dead or alive, to specific surroundings – have also tapped into the data extracted from pollen. So, a shout out to palynologists, who understand so well the value of those grains of plant dust.

Palynologist Dr Kat Holt doing climate research © Phys.org

Yorkhill’s Green Spaces: Perfect for Pollinators

We continue our series of articles looking at the fantastic projects which entered the Keep Scotland Beautiful pollinator-friendly category. Today we feature Yorkhill Green Spaces who won first prize with a wonderfully wide-ranging project that delivers for pollinators and people.

By Scott Shanks

Yorkhill Green Spaces (YGS) are a group of community volunteers in Yorkhill in the west end of Glasgow. They meet regularly for litter-picks, planting and other greenspace management tasks. Their aim is to improve local parks for biodiversity and the community in an area of the City where few people have gardens. The group’s three main sites are Yorkhill Park, Cherry Park and Overnewton Park. These green spaces, close to the COP26 campus provided peaceful retreats for attendees of the recent COP26 conference.

Meadow management day at Yorkhill Park

Yorkhill Park is the largest, and the ‘wildest’ of Yorkhill’s green spaces. It sits on a south-facing slope behind the former Yorkhill Maternity Hospital, close to where the River Kelvin meets the Clyde.

The proximity to these blue-green corridors has helped channel a diversity of species to this wee oasis for wildlife.  In 2021 YGS gained permission to manage about 1hectare of neutral grassland in the park as a cut and lift wildflower meadow. After years as intensively managed amenity grass, and then at least 5 years with no cutting, the slopes were dominated by rank grass with few flowers. To improve the floral diversity about 60% of the slopes were cut in late September 2021 and the clippings raked-up and removed by volunteers to reduce nutrients. Hemi-parasitic Yellow rattle seed was then sown and trampled into the short grass, which will help further reduce the dominance of grass when it germinates next spring. Wildflower plug plants of 15 species have been planted on the slopes, along with crocuses and native bluebells close to foot paths to help bring more spring colour, nectar and pollen for pollinators.

The remaining 40% of the grass was left uncut to provide shelter for invertebrates including Meadow Brown and Ringlet butterfly caterpillars, and habitat for Bank voles which attract the Foxes and Kestrels that are often encountered in the park. The uncut areas will be rotated each year. An additional 400m² of verge was sown with a mix of 40+ native wildflowers and grasses after footpath upgrades created lots of bare ground this year.

Cherry Park and Overnewton Park are more traditional parks, with play areas, seating and short, amenity grassland. Areas were identified in both parks in 2021 that will only get perimeter cuts along the paths in 2022 and will then managed as cut & lift meadows next autumn. We’ve planted a range of spring bulbs in both parks. Flower beds and borders have been planted with pollinator-friendly herbaceous perennials such as Heathers, Lavenders, Perennial wallflower, Hardy germaniums, Lungwort, Fennel and scatterings of Borage and Garlic mustard.  

We created two wildflower pollinator strips at Overnewton Park in 2019 by striping-off short turf and sowing with a variety of native wildflower mixes including cornfield annuals and perennials to give bursts of colour, nectar and pollen for pollinators. Every year they get better and better, although high nutrients led to an issue with invading couch grass in one strip this year. These pollinator strips are cut and lifted in the autumn to keep nutrients low. Crocus, Grape hyacinths and Snowdrops help give the borders and wildflower strips some early spring zing!

We are keen to promote sustainability and only use peat-free media in planters and don’t use pesticides or herbicides. In early 2021 we planted a range of pollinator-friendly herbaceous perennials and grasses in 6 new sensory garden planters (funded by Morrison’s), filled with 4 different brands of peat-free compost. All have been very successful. We also collect wildflower seed in autumn to sow in new areas.

Flowering native hedging planted at Cherry Park in early 2020 and 2021 will help support wildlife including pollinators, acts as a lovely perimeter feature which captures carbon and filters out particles from car exhausts. More native hedging will be planted along the perimeter of Yorkhill Park this winter.

Recording biodiversity during volunteer events has become very popular, and in September 2021 the group recorded their 1000^th species: a wee flower bug (Anthocoris confusus). The YGS species list currently (November 2021) has 1,036 species including 29 species of bees, 21 wasps, 97 flies, 12 butterflies and 202 different moths. One of the exciting 2021 finds was a female Northern sallow mining bee (Andrena ruficrus) which is a Scottish Biodiversity List priority species. This wee mining bee only collects pollen from willows and sallow catkins to stock her nest burrow. 

A dead standing tree in Yorkhill Park has proven to be a fantastic feature for biodiversity. It supports at least 2 species of solitary bees: Red-mason bee (Osmia bicornis) and Patchwork leafcutter (Megachile centuncularis), and at least 8 species of breeding solitary wasps, including beautiful Ruby-tailed wasps (Chrysis ignita). 

All three parks sit within one of Buglife’s mapped B-Lines and help enhance this network of stepping-stone sites for pollinators to move across the city.

The group encourages members and the local community to take part in national biodiversity recording events such as the Big Garden Birdwatch, Big Butterfly Count, National Bee Week, City Nature Challenge, and carry out ‘FIT count’ surveys for the UK National Pollinator Monitoring Scheme.

Looking to the future YGS are keen to improve the habitat connectivity between their parks and other green spaces in Glasgow. Projects for 2022 will include installing further sustainability improvements such as water butts and more compost bins. They hope to convert flowerbeds in Cherry Park into raingardens to help the area cope with more frequent storm events predicted in the future. 

Find out more

Yorkhill Green Spaces Facebook group: https://www.facebook.com/groups/120814735177832

YGS Twitter: https://twitter.com/yorkhillgreen

A sweet and addictive drug

By Athayde Tonhasca

When the Greek gods invited Zeus’ son Tantalus for a feast at Olympus, they couldn’t have imagined their guest had sticky fingers. Tantalus stole their food (ambrosia) and drink (nectar) intending to give the loot to his people to make them immortal and privy to divine secrets. The gods didn’t take the betrayal lightly: they shipped Tantalus to the Underworld and made him stand in a pool of water under the branches of a fruit tree. Every time Tantalus tried to pick up a fruit, the branches would grow out of his reach, and when he wanted to drink, the water would recede away. Next time you find yourself ‘tantalisingly close’ to something but not getting it, spare a thought for poor Tantalus, going hungry and thirsty for eternity.

Tantalus’ punishment for stealing ambrosia and nectar © Jacques Favereau, 1655

The magical diet of the Olympians made such an impression on Western culture that many food and drink products have ‘ambrosia’ or ‘nectar’ attached to their names. Most of them are wishful thinking or just gimmicks, but the term ‘nectar’ was adopted quite appropriately in one case: to label the mixture of sugars and water that can be secreted by any vegetative part of a flowering plant, but mostly by flowers. 

Floral nectar contains 15% to 75% (by weight) of sugars, mostly glucose, fructose and sucrose. Free amino acids, proteins, minerals and lipids add to the nutritional content of the mixture, although we have only a vague understanding of their workings. As a ready-to-use source of energy and nitrogen to a wide range of animals, nectar is fundamental for the support of food webs.

Nectar is a reward to attract pollinators, but it is also a metabolically expensive product: plants can’t afford to give it away willy-nilly. So they may resort to some manipulation, which often involves intoxicating flower visitors with secondary metabolites. These are compounds such as tannins, phenols, alkaloids and terpenes, which have no apparent role in metabolism but may defend the plant against plant feeders and pathogens.

Plants such as citrus, coffee and camellias secrete nectar laced with caffeine. This bitter-tasting alkaloid reduces the palatability of plant tissues, thus protecting the plant against herbivores. But diluted in nectar, caffeine is a behaviour-altering drug: honey bees feed more and do their waggle dance more frequently if they have a sip of caffeine-spiked nectar. Plants can take advantage of this caffeine high; they can reduce the nectar quality, while bees carry on on feeding. That’s not so good for the honey bees, who produce less honey. 

Japanese camellia (Camellia japonica) in a London garden, a caffeine bar for honey bees © Emőke Dénes, Wikipedia Creative Commons

Nicotine, another insect-repelling alkaloid, has a similar addictive effect on bumble bees. Nectar containing nicotine helps bees learn more quickly how to find their food source and once learned, they tend to stick with the same source, coming back again and again. Naturally, this is a good result for the drug-peddling plant. 

Nicotine encourages bumble bees to stick around, but it may send other visitors packing. Just like caffeine, nicotine decreases the palatability of nectar. As a consequence, some pollinators consume less of it but visit more flowers, which leads to a higher rate of cross pollination. The alkaloid gelsemine, found in the nectar of the yellow jessamine (Gelsemium sempervirens), has a similar effect on flower visitors: it decreases frequency and length of visitations but increases the number of flowers visited.

Coyote tobacco (Nicotiana attenuata) (L) and yellow jessamine encourage pollinators to take a sip of their nectar and move on © USDA Natural Resources Conservation Service (L) and Jim Evans, Wikipedia Creative Commons

More than half of all flowering plants secrete secondary metabolites with their nectar, but except for a few cases involving honey bees, bumble bees and some moths, we know little about the effects of these chemicals on pollinators. The scant information we have suggests that nectar is more than a sweet lure: plants use it to manipulate flower visitors for their own benefit, and this often involves the use of addictive stimulants. In nature, anything goes to increase your chances of success.