Choosing garden flowers to encourage bees
In recent years bees around the world have had a very hard time, and are in serious decline in some areas. Beekeepers are losing high percentages of their stock due to such problems as the Virroa mite, and the mysterious Colony Collapse Disorder. It's not just managed beehives that are in trouble either, many wild bees, and some species of solitary bee (eg bumblebees) are also reported to be in decline. This is bad news for the environment, agriculture and the future of our planet due to the vital role that bees play in pollinating plants, in particular our food crops.
There is much speculation about the cause of the decline, ranging from use of pesticides, genetically modified crops, mobile phone signals and loss of habitat. Europe has recently decided to ban the use of a particular pesticide containing neonicotinoids, which have been shown to contribute to bee death - let's hope this has the desired effect. Whatever the cause of the trouble, you can help to make a difference by providing a little bit of habitat to encourage bees to feed and breed in and around your garden. Most importantly is a food source, and as bees feed on nectar you can make a really big impact by providing the kind of nectar rich flowers that your local bees will love.
A general guide to choosing the right flowers is to choose some native flowers that grow well in your local area, and are known to be frequented by plenty of insects. You could throw in a few attractive wild flowers, such as ox-eye daisies, poppies, scabious etc, but they don't all have to be weeds! Cottage-garden type flowers are particularly good, such as sunflowers, hollyhocks, delphiniums, lupins, rudbeckia, foxgloves and so on. Sweet scented herbs such as lavender, rosemary and thyme are also very popular with bees. Exotic species don't do any harm either, there's no reason why you can't include some big colourful foreign flowers, but when choosing varieties go for the single flowered types rather than double flowers, as bees find these easier to get into to feed on the nectar. Bees also love flowering fruit trees, and will reward you by pollinating the fruit. Other bushes and trees that will encourage the bees into your garden include buddleia (which is also great for butterflies), skimmia, hawthorn, viburnum, rhododendrons and potentillas. Try to choose a good selection that will provide nectar all year round, including plants such as early spring bulbs.
The recommendations here are based on an English garden, but whatever part of the world you are from, the general principle will apply. Provide food for your local bees, and they will pay you back tenfold by pollinating your flowers, fruits and local agricultural crops, and if you are lucky you may even get some local honey.