Autumn can be the most colourful time of year in Languedoc, and I’ve often wondered why it is that the colours can be so different from one year to the next – haven’t you?
In preparation for this post I decided to do some research, and found the answers. In simple terms (I’m not very good at complicated), it appears that it works as follows: in autumn the trees stop photosynthesis and the chlorophyll which gives the leaves their green colour is broken down into other components, to be absorbed and stored by the tree. In some trees such as aspen and linden naturally yellow pigments are present in the leaves (carotenoids – also found in carrots), and they are usually masked by the chlorophyll. So when that disappears the naturally yellow colour reappears.
Now for the reds: red and purple leaves occur on trees where the yellow isn’t present, and the pigments responsible for that colour are called anthocyanins. They are produced by the tree at the end of the summer, and from what I understand they protect the leaves from the sun while the tree absorbs all it can from the leaves – similar to sunscreen for us.
So that’s the basic science behind the colouring. The articles I found were all about trees but I imagine that the same goes for the other plants whose leaves turn brilliant shades of red and yellow. But I was still looking for more: why can there be brilliant flares of orange and russet all over the countryside one year and the next year it just looks like dull shades of brown and ochre?
Apparently that’s all down to the weather! The colours develop best if the days are warm and the nights cool and crisp but not freezing. And then you need enough moisture but not too much, so all in all you can see why the colours can vary so very much from year to year. Except for the yellow of course, which is always there. But there are other fall colours apart from the leaves 🙂
The olives turn from green to black, going through wonderful shades of purple – very well imitated in some of the olives made from chocolate! Persimmons turn a beautiful shade of orange and every so often you’ll find a bunch of grapes left behind. And then there are the strawberry trees, called arbousier in France (arbutus unedo), evergreen trees which grow wild all over the countryside. They flower in late autumn, at the same time as the fruit from the previous flowering ripens.
If you get a chance to pick enough, the fruits can be turned into arbousier jelly. Years ago Madeleine, who lived across the road, showed me how to make it. The fruit is boiled with a little water until all is mush; left to cool the mush is then strained, and Madeleine insisted that the best way to do this was through one of her sturdy tights (not laddered and washed of course!), and she was of course right! It’s a little messy, but once the pulp is all in the top is knotted and then you just squeeze the whole thing gently with your hands until the strained pulp ends up in the bowl over which you are working. Some of it will of course end up covering you! The pulp is then weighed, the same amount of sugar added, along with a little lemon juice and then boiled to a set. These days I use 2:1 jam sugar, making a jam/jelly which is less sweet. Arbousier jelly has a very delicate flavour, reminiscent of apricot.
And there are other berries in all directions – though I’m not sure what those wonderfully red berries are called?
The two most helpful articles about leaf colour were found here and here