Nectar and pollen are essential food sources for pollinators such as bees, butterflies and hoverflies. Nectar is essentially sugar water – insects drink it and the sugar gives them the energy to fly to find a mate or to start a nest. Nearly all pollinators drink nectar, including bees, butterflies, flies and wasps.
Pollen is protein. Bees gather pollen to feed their young, which they need to grow. Studies have shown that the larger and more robust bumblebee adults were fed more pollen when they were grubs. Pollen is therefore essential for the health and vitality of adult bumblebees. The quality of pollen varies from flower to flower – leguminous flowers, such as those of peas, beans, clover and vetches, has the best quality pollen, which makes for even healthier adult bees.
Butterflies, moths, wasps and hoverflies don't gather pollen to feed their young. Butterfly and moth caterpillars get their protein from leaves, and most hoverfly larvae get their protein from aphids (although some hoverflies lay eggs in stagnant water and their larvae eat the algae and bacteria from the water). Wasps gather insect protein for their young, such as caterpillars, flies and other grubs.
In the British isles there are nearly 270 species of bee, over 50 species of butterfly, 2500 species of moth, 9000 wasps and 280 species of hoverfly. If they were all on the wing at the same time, there would be a huge competition for pollen and nectar. Instead, some emerge early in the year while others fly much later. For example the red admiral butterfly is one of the first butterflies to be seen at the beginning of the year, while the ivy bee doesn't emerge from hibernation until September, long after most other species have finished nesting. What's more, climate change is extending the season for some pollinators, which are emerging earlier in the year and not entering hibernation until much later than they used to. When gardening for bees and other pollinators, it's therefore important to offer a continuous source of nectar and pollen for as long as possible.
As wildlife gardeners, we should aim to grow flowering plants from March to November, which provides food for the earliest and latest pollinators. Even better, why not grow flowers all year round? Below are some suggestions for flowers that provide a 12-month supply of pollen and nectar, so any pollinators on the wing can find food in your garden.
Most pollinators don't emerge from hibernation in spring, but some are on the wing a little earlier. Honeybees and bumblebee queens might emerge on mild days in search of nectar, before returning to the hive or hibernaculum. In the south of the UK, some bumblebees don't hibernate at all but start a new nest, instead. Look out for small bumblebees gathering pollen from winter flowers such as mahonia.
Red admiral butterflies often emerge on sunny days and fly around before returning to shelter. You might see the odd hoverfly on sunny days, too.
These pollinators rely on nectar to give them the energy to return to shelter to see out the rest of winter. Winter bumblebee colonies are particularly reliant on winter flowers as they need pollen to feed their young. Plants in flower in January:
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Winter aconite, Eranthis hyemalis
Low-growing, yellow flowers in January and February.
Clematis cirrhosa, including ‘Freckles’ (pictured)
Evergreen climber wth flowers n December and January.
Oregon grape, Mahonia x media
Evergreen shrub. Some varieties flower from November to March.
Dry, sunny days will bring more pollinators out in search of energy-giving nectar. Some hoverflies, such as Eristalis tenax and similar species, will be on the wing on such days. In the south, some species of bumblebee may start looking for a nest (and therefore start collecting pollen). Plants in flower in February:
Snowdrop, Galanthis nivalis
Low-growing bulbous perennial, flowers from February to March.
Crocus, Crocus tommasinianus
Adored by bumblebees. Look out for queens clinging onto unopened flowers on gloomy days. Flowers from February to April.
Winter-flowering heather, Erica carnea
Flowers from January to May. Particularly useful for bumblebees and honeybees.
More flowers are emerging in March, and more pollinators are visiting them. Look out for early butterflies such as orange-tip and brimstone, along with nest-searching bumblebee queens, and honeybees. Plants in flower in March:
Different species flower from January to April.
Primrose, Primula vulgaris
Flowers March to May. Particularly suited to long-tongues pollinators, such as the hairy footed flower bee.
Hazel (catkins) Corylus avellana
Hazel catkins are wind pollinated so don't produce nectar, but bees gather their pollen to feed their young. Flowers February to March.
Rosemary, Salvia rosmarinus
Rosemary flowers from March to May, and is popular with bumblebees.
Another weed, dandelion produces nectar and pollen when few other plants are in flower. Flowers March to October.
April is a busy time for pollinators. They are therefore busy foraging for nectar and pollen. While flowers supply all the nutritional needs of bees, butterflies and moths lay their eggs on leaves. Find out what to grow for them in our feature on caterpillar food plants. Plants in flower in April:
Despite being wind pollinated, willows also produce nectar. Flower March to April.
White dead nettle
Widely considered a weed, white dead nettle is an important food source for a number of pollinators, including rare bumblebees. Flowers March to December.
Flowering in April, apple, cherry, pear and other spring blossom provides masses of pollen and nectar for pollinators in a very small space. Look out for solitary red mason bees on the flowers.
Flowering from March to May, lungwort is favoured by the hairy footed flower bee, and flowers in shade.
Grape hyacinth, Muscari armeniacum
Low-growing bulbous, spreading perennial in flower in April and May. Adored by bees.
Cuckoo flower, Cardamine pratensis
Flowering for a short time, this native perennial is perfect for growing at the pond edge. Orange-tip butterflies feed on the flowers and lay eggs on the leaves.
Many more plants are in flower in May, as nesting continues in earnest. Bumblebee nests are increasing in size, and some early nesting species, such as Bombus pratorum and Bombus hypnorum, start to produce males, which means their nests will soon come to an end. Other species are just emerging. Look out for small tortoiseshell and peacock butterflies laying eggs on nettle leaves, while nectaring on flowers such as dandelions and forget-me-not. There are so many plants to choose from, but here are some plants in flower in May:
Hawthorn, Crataegus monogyna
Flowers from late April to May. Flowers are popular with flies, including hoverflies.
Oriental poppies, Papaver orientale
Poppies don't produce nectar but provide copious pollen, loved by bumblebees. Flowers from late-May to June.
There are many different allium species, most of which flower from May to June. Bees, butterflies and hoverflies flock to them.
Foxglove, Digitals purpurea
Popular with long-tongued bees such as the garden bumblebee, Bombus hortorum.
Honeywort, Cerinthe purpurescens
This hardy annual flowers all year round but mostly from May to July. Bumblebees and solitary bees are regular visitors to the nectar-rich flowers.
Also in flower in May: lupin, red campion, red clover, white clover, bird’s foot trefoil
The 'June Gap' is a phenomenon described by bee-keepers, which suggests there is a shortage of nectar and pollen in the wild, just as honeybee colonies (and therefore bumblebee colonies and solitary bee nests) are growing rapidly. There's plenty to grow in our gardens to make up for this loss in the wild, below are some of the many options. Plants in flower in June:
Borage, Borago officinalis
One of the best plants for bees, studies have shown its flowers refill with nectar every two minutes. Flowers June to September.
Viper's bugloss, Echium vulgare
Another fantastic plant, butterflies and bees will flock to its nectar-rich flowers. Flowers June to August.
Mountain cornflower, Centaurea montana
Flowering from June to August, mountain cornflower is very popular with bees.
Raspberry, Rubus ideaus
Popular with a variety of pollinators, particularly wasps, which seem very attracted to the flowers. Flowers June to July.
Also in flower in June: knapweed, heather, cranesbill geraniums, speedwell, catmint
Things start to die down in July, especially as many bumblebee nests come to an end. Garden butterflies take centre stage from now, feeding on nectar-rich buddleia, knapweeds and scabious. Plants in flower in July:
While oregano is usually used for culinary purposes, if you let it flower it's one of the best sources of nectar and pollen for pollinators. The variety 'Rosenkuppel' is particularly ornamental. Flowers June to August.
Popular with a number of different pollinators, agastache flowers from June to October.
A firm favourite with butterflies, scabious flowers over a long period, from May to September.
Also in flower in July: comfrey, salvia, verbascum
Many summer flowers have already finished, as have some pollinator lifecycles. Now it's the job of the late-summer/autumn plants to continue to the season of nectar and pollen for pollinators. Here's what's in flower in August:
Cardoon, Cynara cardunculus
This relative of the globe artichoke is hugely popular with bees, butterflies and hoverflies alike. Flowers from June to September.
A wide variety of pollinators visit catmints, which flower from July to September.
Also in flower in August: globe thistle, sunflower, yarrow, hollyhock, angelica, cosmos
Most pollinators have finished nesting by September, apart from the ivy bee, which starts nesting this month. Some bumblebee nests might still be active, although dwindling. Butterflies such as small tortoiseshell, peacock and comma are still on the wing on sunny days, nectaring on late flowers. Here's what's in flower in September:
Ivy, Hedera helix
English ivy flowers offer an extremely important late source of nectar and pollen at a time when there's little else in flower. The blooms are noisy with late bees, butterflies, flies and wasps.
Known as the butterfly bush, this Chinese native is popular with bees and hoverflies, too. Cut plants back hard in May to ensure they flower as late as possible.
This late-summer staple is perfect for filling gaps in the border left by summer-flowering annuals. Flowers July to September.
Ice plant, Hylotelphium spectabile
Another late-summer staple, ice plant is popular with butterflies. Flowers from August to October.
Fewer pollinators are on the wing this month, but sunny days will bring out butterflies and hoverflies, and the odd late bumblebee. Pollen becomes less important in October, as most bees are no longer nesting. However, they still need nectar for energy. Flowers to grow this month include:
This tall, graceful perennial is a stalwart of the autumn garden and prairie plantings, and popular with late butterflies and bees.
Also found in prairie pantings, rudbeckias come in a variety of looks, but all are popular with late pollinators.
It gets harder to keep the borders going this month, as frosts wipe out the last of the summer perennials and little else starts to bloom. In mild regions, keep deadheading plants such as cosmos and dahlias, which will keep flowering until the first heavy frosts. Meanwhile, these plants will help you keep something in flower in November:
Erysimum Bowles's mauve
Perennial wallflower blooms for many months. In the south of Britain it can flower continuously for 12 months of the year. Sterile, it doesn't produce pollen, but is a good nectar plant for a wide range of pollinators.
Many cultivars of this New Zealand native flower continuously from summer until the first frosts, providing a good source of nectar and pollen for a wide range of pollinators.
December is a dark month, and little is in flower. Some species of mahonia will be in flower now, along with Viburnum x bodnantense and sweet box. For options that take up less space, try:
Also in flower in December:
This low-growing perennial can flower as early as December, and is perfect for naturalising beneath trees. Flowers from December until April.
Winter honeysuckle is a magnet for any bumblebees on the wing in December – be they queens disturbed from hibernation or workers from a winter-active colony. The fragrant blooms are excellent for cutting, too. Flowers November to February.