Why city gardens are ecologically important
During the last decades there has been an alarming decline in bee populations caused by a combination of climate change, habitat loss, pesticide use, draught and nutritional deficiency. I emphasise the word alarming, because without domestic and wild bees we humans will have a very hard time producing our food since 70% of our top food crops are pollinated by bees! Imagine a world without fruit or vegetables, beans or nuts and you see the problem. The solution would be to ban the worlds most dangerous pesticides, convert more land to ecological/ organic farming and perserve wildlife habitat. For the average person, this may feel very depressing as few of us have the means to really influence these things appart from consistently choosing the organic alternative when shopping. Gardeners, however, have a unique chance to make a difference by providing alternative habitat to bees.
In urban areas there is a lot of green space made up from private gardens, parks, graveyards, allotments and general communal spaces. Even a small city garden can be a safe haven providing food and shelter, and all that is needed is a few tweaks and some planning. One of the simplest ways to make your garden attractive to bees is to leave a part of the lawn un-mowed and let ordinary weeds such as dandelions and daisies flower, and to chose decorative garden plants with an eye as to how much they support the insect population. A native or cultivated native variety such as Hawthorn (Crataegus) or Bird Cherry (Prunus padus) will provide much more pollen and nectar than some of the pretty but sterile flowering cherries available, while still having the added bonus of featuring berries in the autumn.
In the city garden it is easy to imagine that a lack of space would be a hindrance to creating valuable insect habitat, yet this is not necessarily so. Think in terms of layers! Walls can be used for decorative climbers such as Wisteria, which is an excellent pollen plant for bees when it flowers in long and beautiful bunches of blue or white flowers. If you live in a cold climate zone like I do where the winter frost kill it off immediately, you can use hardier climbers such as Honeysuckles (Lonicera) that smells lovely in the evenings, or one of the many varieties of Climbing roses (of which there are surprisingly hardy varieties) that survives the winters. Boundaries can be planted with different kinds of shrubs and layered with underplanting, with all plants selected for their capacity to feed wildlife. Even formal borders can be designed with bees in mind, especially when considering that if there is always something flowering in your garden then your bee restaurant is always open! It is therefore not necessary to strive for an enormously complicated planting scheme, but simply one which has a few well chosen sorts of flowers on display at all times.
All flowering plants are good sources of pollen and nectar, but some are better than others. In spring you may want to start with spring bulbs such as Snowdrops, Alliums, Siberian squill (Scilla siberica), Crocuses and Daffodils, all of which are important food sources to newly awakened and famished bees. Then there are perennials such as Bee balm (Monarda), Lavender, Echinea, Anise hyssop (Agastache foeniculum), Campanula (different kinds of bluebells) and perennial Cornflowers (Centaurea Cyanus), Sea holly (Erignium) and Geraniums that are extra attractive to bees. If you live in a warm climate, Buddlia (Budelia davidii) is one of the very best flowering shrubs for bees, but if not and you live in a cold climate like me then go for lilacs (Syringa vulgaris) or Viburnum shrubs. Often, when it comes to providing pollen and nectar, single flowering cultivars are better than complex double flowers. When sowing annuals simple flowers such as Marigolds, Borage, Sunflowers and Cosmos can really brighten up the garden while at the same time providing a wholesome buffet for the bees.
In small city gardens, there is one thing that is a must: the herbs! Herbs are to their nature highly aromatic, and therefore most attractive to bees. If they are placed close to the entrance of the house, they are ready at hand to be used in the kitchen when cooking. The best herbs for attracting bees are some of our most ordinary ones too; rosemary, thyme, marjoram and lavender. These all prefer a sunny spot and fairly light soil, and as they grow woody with age it is only preferable that you cut them for use in the kitchen. (Although having said that, lavender is more often used as scent than in cooking!) For north-facing and more difficult aspects in the garden a great herb to use is mint. There are more than twenty different cultivars of mint such as pineapple mint, peppermint, thai mint and spearmint, but they are all more or less equally resistent to adversity and can survive in even dry shade. However, if you care for it and give mint good compost it will thrive and flower all summer long, a most popular feeding plant for bees. But do note, it may thrive a bit too well so it is best planted in pots or a flowerbed separated by proper borders as otherwise it starts to wander off and becomes a weed in the rest of the garden...
Last but not least: remember to leave some part of the garden unkept and "wild" for the bees and other wildlife to nest in. We all love to feel good about doing good, but the reality of living with a bees nest in your garden can be challenging. Solitary bees may be attracted to nest in insect hotels of different kinds, but few people want to have a wasps nest at their entrance. However these too are important in the ecosystem so if at all possible try to be equally welcoming to all the bees, including honey bees, bumblebees and wasps. As an addad bonus, caring for bees will simultaneously attract butterflies and moths into your garden which are bound to put a smile on your lips as they flutter past in the sunshine!
(For more information there are some wonderful resources available just one click away, like Buzz About Bees, the Bumblebee Conservation Trust, Pollinera Sverige, Svenska bin and the Honeybee Conservancy organisation.)