Grey mould on vegetable plants – Diary of a Rocket Gardener

I didn’t pay much attention to the courgette leaves turning mouldy over the past few weeks. I figured it was just a severe case of powdery mildew and that the plants were nearly over anyway. But then I saw a similar grayish mould on a few other plants, like this previously healthy savoy cabbage that I was looking forward to harvesting.

It’s not something I’ve really noticed in the past, so I did some research online and the thing I found is something called Botrytis. It’s also known as grey rot or grey mould, and apparently it’s a gardener’s nightmare. As I understand it, it is a particularly fast spreading mould that affects plants that are damaged or stressed in some way – no surprise then that my water-deprived courgettes and cabbages got hit!

Apparently, the mould spores can live in the soil for some time, like months, not weeks, and hence can contaminate future crops. This doesn’t bode well, and the general advice is to remove any infected plants asap and burn them rather than adding them to the compost pile.

However, I’m encouraged by my reading around the no-dig method of growing vegetables and the stories that I read from other growers who, by mulching heavily with compost, see an improvement in the soil and report that their plants are healthy and that they do not struggle with repeated attacks of fungal disease. This really resonates with me – it’s like the plants have an immune system, and if they’re doing well they will be better able to fend off diseases. This year, with the long drought, the vegetable plants had to dig deep to find water. Whilst mine did really well on minimal watering, there was still significant stress. You can see this on the cabbage plant by the pink tinged leaves, a sign of nutrient deficiency due to lack of moisture in the soil and an inability to draw the food they need through their roots. With this in mind, I think it is unsurprising that they succumbed to this grey mould this year. It’ll be interesting to see how the plants fare next season and whether this grey mould does indeed become a recurring problem for me in the veg patch now.