How to turn up the colour on autumn’s amazing show | Gardening advice
EEveryone has one of those seemingly indestructible friends. You know, the ones who run marathons in heat waves, go swimming in the sea in the dead of winter, and whatever the weather, they kind of have a huge, earthy smile on their face while they do it. So when I was invited to the October wedding of two such friends, held in a gathering of tents in a Welsh forest where activities included lake swimming and an outdoor log sauna, my poor tropical physiology was set for the worst.
Yet from the moment I arrived, just as the leaves were blushing their autumnal hues, I was struck by their incredibly uplifting power, made even more intense by the amount of time I spent with them – and so breathtakingly beautiful, that I hardly noticed the cold. We gardeners spend so much time improving the size and quality of flowers, fruits, and vegetables that I was really wondering what we could do to improve the fall foliage drama.
As with pretty much every aspect of gardening, there are two key factors that determine the quality of fall color: the plant’s unique genetics and the cultural conditions you subject it to. While there are many lists of plants whose leaves turn bright yellow, orange, or red before falling, there’s a lack of focus on how to further intensify those hues. I think that’s a shame, as theoretically this should be relatively easy.
The yellows and oranges of fall leaves show up when the green pigment chlorophyll is drained at the end of summer. The remaining orange pigments, known as carotenoids, that have been present all along, help perform a number of biological functions, including acting as UV protectants to prevent cell damage. Because plants grown in brighter conditions produce more carotenoids, for the most dazzling yellows and oranges, simply choose the sunniest spots to plant them.
But what about reds? Well, while the evolutionary reason plants do this is still a mystery hotly debated by botanists, we do know how they do it. Made by pigments called anthocyanins, unlike carotenoids, these are only released when temperatures drop. So if you choose a colder spot, ideally without too much wind to blow the leaves away, you would get the hottest shades. A good choice for example for a frost pocket in a sunken area.
However, the easiest way to enjoy most fall colors is to find an excuse to get out and see them. Wrap up warm, invite your friends to a fall barbecue, mix up a cauldron of hot toddies and take it all in. The British tradition of standing around an open fire on the hottest day of the year is a bit crazy anyway, especially when doing it now gives you the chance to experience a natural wonder you might otherwise miss indoors. A lesson I learned from my friends wedding this year.
Follow James on Twitter @Botanygeek