Nectar is the sweet liquid which flowers produce to attract pollinators such as bees, moths, beetles and hoverflies. (Fancy a taste? Pull off the flower of a white dead nettle, without breaking it, and suck the end that was attached to the plant. You'll find a bee-sized mouthful of sweetness).
As a rule of thumb, the best nectar plants are the ones closest to their wild cousins. Highly decorative or double-flowered varieties, which have been selectively bred for their appearance, often have little or no nectar value. The more nectar your garden has on offer, the more pollinators will visit - and where they come, other animals aren't far behind. In June and July, these visitors are spoiled for choice. But in spring and autumn you can really make a difference by planting flowers which offer a sugary drink when little else is around.
Suggested plants for a long nectar season >>