Pollinator Plants

Want to help stop the widespread decline of bees and other airborne insects? Here are some notes on the Garden’s plants most visited by bumble bees, hive bees, hoverflies and the occasional butterfly. Most of these plants are easy to grow.

One of the main aims of the Living Field garden is to allow native cropland plants some space away from weedkiller treatment and competition with crops. Recent scientific reports have drawn attention to the widespread loss of invertebrate life and insect life in particular. The declines are happening all over the world.

Everyone who owns or manages land can do their bit to support flying insects. Here we show some of the Garden’s plants and plant groups that have offered food and shelter to flower-visitors over the years.

The legumes

Legumes – (upper) sainfoin, (middle) lucerne and white melilot then (lower) tufted vetch – Images by Living Field

The legumes (family: Fabaceae), just ahead of the Composites, are the single most important group supporting wild flyers. The legumes as a whole offer probably the greatest variety and longest flowering season of all plant groups in the garden. They fix their own nitrogen from the air. All parts of the plant are high in protein.

Sainfoin, the melilots and lucerne were once grown or tried as forage crops in Scotland. The clovers, mainly white and red, are still sown, but the red is more commonly seen in the wild. The bumble bees’ favourite of them all is the blue-flowered, tufted vetch (lower images in the panel) – its strings of flowers produced for months on indeterminate sprawling and clinging stems.

The composites – thistles and knapweeds

The composite family – hemp agrimony (upper), greater knapweed, tansy and common thistle (middle), cotton thistle (lower) – images by Living Field..

Next are the composites (family : Asteraceae), each flowering head consisting of many individual florets. Not all species are equally visited, but the best here for pollinators are thistles and knapweeds. The great cotton thistle grows like a small tree, supporting large heads several centimetres across, bumble bees often bustling two or three to a head.

The greater and common knapweeds, hemp agrimony and tansy shown above are perennials, whereas the thistles in the garden tend to be biennial – germinating one year, overwintering as a rosette and flowering the next. The weedy perennial creeping thistle is too invasive in the garden’s small space and though it supports insects is discouraged in favour of other thistles.

Field scabious and teasel

Field scabious in the meadow, attracting a wide range of pollinator species, flowering for the longest period in the Garden – images Linda Ford / Living Field

Of all the species in the garden, field scabious (family: Dipsacaceae) is the one that offers sustenance to flyers for the longest period. A perennial, growing mainly in the meadow, plants put out flower after flower from early summer to late autumn (except in the very dry 2018). If there was one plant that we could grow for the bees, it would be this.

Teasel is a close relative that also grows well here. It self seeds and is mostly biennial. Plants are moved at the rosette stage in autumn or early spring to form clumps that flower in the medicinals bed.

Labiates – mints, sages, deadnettles and woundworts

Labiate family – betony (upper), sage (lower rt) and clary in the meadow – images by Living Field.

The labiate family (Lamiaceae), including mints, sages, woundworts, deadnettles, hempnettles and basils – are well represented among the medicinals and herbs. They grow in sun, in shade and as occasionals anywhere. The large flowered types such as the herb sage are most frequently visited by the Bombus species, while betony tends to attract more of the smaller carder bees.

The smaller flowered species, such as meadow clary (a perennial n the meadow), fields mints, hempnettle and wild basil are less attractive to larger flying insects but have their own specialist range of inverts.

And many more when the weather’s right

These are not the only plants that offer food and shelter for flying insects. Among the first in the year are the flowers and leaves on the garden’s native trees and shrubs. Early summer in the hedges, flowers of wild roses offer a welcoming landing platform for grazing hoverflies.

One of the longest flowering species, not shown here in the photographs, is viper’s bugloss Echium vulgare, one of the borage family. (See it at the Bee plants links below.) Borage itself and the comfreys are also well visited.

Populations of bees and other flower-visitors were very badly affected here by the dry 2018. There was little left in flower by the end of August, while in most years the field scabious and viper’s bugloss are still visited in late October.

The coming year’s weather is uncertain as always, but we’ll try to manage the plants to give the longest possible season to the resident insects and spiders. First out will be the willow ….. .

But not the main crops

Nearly all the plants referred to here are native species or ones introduced long ago and now naturalised. Very few of the crops grown in the region (and the garden) – barley, wheat, oats, peas – support or need pollinating insects.

Oilseed rape fields provide a crop-based source of food for a few weeks early in the year and field beans also offer high-protein flowers much later. But the main sown crops and leys that could provide the right seasonal habitat – the legume forages and grass-clover mixtures – are rare and mostly long gone.

In the broader landscape therefore, the main source of food for flying insects lies in the broadleaf ‘weed’ species that live in crop fields and disturbed margins – in fact most of those shown in the panels above belong in this category. These arable plants, mostly not injurious to crops, have declined over the last century to the point where many of the plants themselves are now rare. It’s no wonder insects apart from pests are having a hard time in cropland.

Contacts

The Living Field’s page on Bee plants give further notes and images of the individual species most frequently visited in the garden.

As usual, the plants are grown and tended by Gladys Wright and Jackie Thompson with help from the farm.

The photographs of the insects on field scabious were taken by Linda Ford on an ideal summer day a few years ago, the others by Geoff Squire. Colleagues from the farm cut the Living Field meadow once a year and trim the hedges in sequence every few years to allow flowering and fruiting (e.g. for roses, willow, hazel).

Contact: geoff.squire@hutton.ac.uk or geoff.squire@outlook.com

Three grain resilience

The north-east Atlantic seaboard has grown three main grain crops – oat, barley and wheat. All originated in the east Mediterranean or west Asia, but all find the climate here good for their growth. Most years that is.

The fall in output of the main staple grain crops in 2018, and before that in 2012, due to unusually bad weather, raised many questions as to how food and alcohol production would be affected if the climate continued to vary between wet and dry. The crop in 2012 suffered from cloudy skies causing slow plant growth, and then very wet soil that made harvest difficult. That in 2018 suffered from lack of water mid-May, at just the point when the crops were starting their main phase of growth.

Yet in neither year did production collapse. Total grain output from wheat, barley and oats fell by little more than a tenth of the average. Perhaps the varied needs of the three grains give cereal production here its ability to withstand years of bad weather. Historical change in this combination of grains may tell much about how agriculture can cope with the future.

Here, we look back over 150 years to see that the balance of the three grains and other crops has undergone major change, most of it not due to the weather, and ask whether the three grains give production some resilience – a capacity to withstand shocks, to adapt and continue.

1900: decline in grain output, a move to grass

In and around 1900, and for many decades before that, oats was by far the most widely grown grain crop in the northern part of Britain. In the crop census for Scotland [1], oats occupied more than three-quarters of the cereal area, and barley most of the rest. Wheat was minor. Few other cereals were grown – a little rye and some ‘mixed grain’ usually consisting of oats and barley.

It was a time of great change, most of it considered negative for home production. The area sown with cereals decreased as did that of the ‘root’ crops (turnips and swede) and also the grain legumes (peas and beans). They all gave way to grass, to feed cattle and sheep, with the result that the country was far from self-sufficient in grain at the time of WWI.

From privation to food security: 1945 – 1990

The areas grown with cereals and other arable crops kept on falling until the start of WWII when the need for home-grown food and feed caused some of the grass to be re-ploughed and sown with arable. The proportional areas of the three cereals remained the same, except for a little more wheat.

Yield per unit area had not changed much from 1900. Something had to happen. The privations of the war years and reliance on imports to feed the country spurred government into action. Plans were laid to raise farming output, but it was well over 10 years before there was any improvement in yield.

The phase of ‘intensification’ really began in the 1960s – machines could plough deeper, mineral fertiliser was readily available and new crop varieties were introduced able to allocate more of their mass to grain rather than straw. By the 1980s, yields had more than doubled. This result of intensification was a major achievement, reproduced in many parts of the world (The Green Revolution).

The largest single change here during that time was a shift from oats to barley and wheat. They were more profitable than oats and could now be grown to higher yield and over large areas with the fertiliser and pesticides that became readily available. Most of the wheat and about 20% of the barley were autumn-sown winter crops. They were able to survive the cold of winter and be ready to bulk up on the sun’s energy as early as May, and so were higher yielding than the traditional spring varieties.

By the 1970s, the country could have fed itself from home production, but then a rise in global trade meant that cereal food could be imported on the cheap. Home production became almost irrelevant to peoples’ consumption of cereal products except oats.

The great levelling : 1990 to the present

The seemingly unstoppable rise in grain yield slowed in the late 1980s. The brakes were on – for various reasons (which will be looked at another time). Yields per field and total grain output from the country have hardly changed since. They go up, as in the favourable weather of 2014, and down as in 2012 and 2018, but their present trajectory is level.

It’s the same for grain output in much of Europe, and crops farther afield, such as oil palm, also suffer: years of expansion and rise in output are followed by a levelling.

The levelling presents a major problem for science and crop management. 2014 gave the highest average yields ever in the region expressed as grain mass per unit field area. There is still potential for increase. The maximum on-farm yields are much higher than the average. Possibly modern varieties, able to yield well in good years, are over-sensitive to bad years.

Lessons from the past

The great swing in the mid-1900s from mostly oats to mostly barley was caused by markets and new opportunities for trade. Science and technology provided the means but the markets drove the change. Government strategy was to gain self-sufficiency in food, but that sufficiency ultimately came from outside.

There was no real strategic plan for home -grown production and there does not seem to be one now. That farming can switch between the three grains (and between grain and grass) should make agriculture less at risk of future catastrophe, whether due to climate. volcanic eruption or blockade. But the country should not wait to see what happens.

The resilience afforded by oats, barley and wheat should now be planned into the future of farming here. The Common Agricultural Policy did little to challenge current markets and the dominance of the few major influences. Post-CAP there is an opportunity to set targets for home-grown cereal food as distinct from cereals as substrates for animal feed and alcohol. Tinkering round the edges will do little. Major structural change in land use is needed.

Some previous posts on this web site have looked at the effects on crops of unusual weather in the past decade [2]. Future articles and notes will look at how farming used the three grains to the lessen the damage caused by the 2018 drought. We’ll also be starting a major series of articles on the options for future sustainability, with reference of course to lessons from the past 5000 years.

Sources, links

[1] A longer version of this article is available as on the curvedflatlands web site: Resilience in a three-grain production system, where full reference is given to the government statistical records from the late 1800s to the present and commentaries on trends in areas and yields of the three grains.

[2] Related topics on the Living Field web site: Winter flood on the water-field pages and The late autumn floods of 2012. For our general educational work on grains, see Ancient grains at the Living Field – 10 years on.

Author contact: geoff.squire@hutton.ac.uk, geoff.squire@outlook.com

[Last update: 16 March 2019, with several textual corrections! GS}