What is Leaf Spot?
Spinach, chard and beetroot are prone to chocolate leaf spot.. These chocolate brown/purple spots are a form of fungal leaf spot that is more likely to affect you if you’re in a wet but mild part of the country. It often affects us here in Cornwall, for example, where we tend to get a lot of heavy rain over autumn and winter, but the daytime temperature is quite warm compared to other parts of the country.
Dealing with Leaf Spot
It’s not really a major problem, and tends to be more of an issue because it is aesthetically unappealing (you can still eat the leaves cooked if they have a few spots on), but it’s also not great to let it get out of hand because then you probably won’t want to eat your leaves.
First, make sure your plants are well spaced - you may find it is better to thin out your plants a little. If you have several plants growing out of one plug, for example, you could pull out to leave just one plant. If plants are practically touching each other, then you may choose to harvest alternate plants as cut and come again, by cutting off all the leaves at about 10-15cm from the ground. This will give the plants more air to circulate, and the leaves will soon grow back.
If you see any spots appearing, you can remove the affected leaves and get rid of them. Doing this will certainly slow it from spreading through the plant, and hopefully prevent it from spreading to other plants but may not get rid of the problem once and for all.