Mildew


By Johnny Phantom - Posted on 11 September 2011

Hello Charles,

Following your tips and advice over the last few months, we've experienced a great summer with an amount of vegetables that very pleasantly surprised us!
You may remember we had some problems with tomatoes... well, they all went on to grow healthily and we've had over 8kg of golden currants already... from eight plants. And they don't yet show any signs of stopping!
During the summer, we also had some peas - Carouby de Maussane - that, due to tying them up too tightly, were affected by mildew. The mildew now seems to have spread to some cabbages and sprouts that were growing nearby - interestingly, there is a lane at the back of our house, and there is mildew on the wild plants up and down the lane, so I wondered if it was in fact something 'in the air'.
My first question is, does powdery mildew make leaves of brassicas inedible? We often trim the odd leaf from cabbages as they're growing, but have avoided eating any of the ones that are obviously affected by the mildew.
My second question is, does powdery mildew kill off plants? We trimmed some of the worst affected leaves off the plants, and they all seem to be doing ok, at the moment.

Thanks,

JP.

 Hi Johnny, good news on tomatoes!

Powdery mildew, soft and fluffy on top of leaves, looks worse than it is and mostly affects older leaves, not often the ones you might eat, but can be washed off to eat them. Yes there is a lot around, for example I have some on kale which was covered with mesh until Saturday and am not worried about it. It certainly won't kill them, they are in full growth.

On the other hand, peas in late summer often suffer badly from it and hence my suggestion to sow peas in March to early May rather than June and July. It is a natural occurrence as the pea plants' energies turn towards fruiting in autumn. Similarly with courgettes and squashes so don't worry if you see it on their leaves, the older ones mainly.