Mildew on leaves of cucurbits like squash, courgette,
pumpkin, cucumber.
Does one need to worry about it?
I know that it looks bad, and I get a lot of questions like 'should I take them off?',
you know, 'what's going on?' and 'what do I do with them?'
As you can see, I'm just leaving them on here. This is courgettes which have been cropping for over three months now.
So they were sown mid-April greenhouse, planted mid-May,
started cropping early June even, that's weird. Now, 8th of September and they're coming towards the end of their life. And that means that
the leaves that they had on them when they were younger, they don't need any more they -
it's- it's natural senescence, if you like,
normal decay. And
mildew, I- the way I look at it, is that the mildew is
helping those leaves to- to break down, if you like, and to become food for
the next generation of plants. Even, even maybe these same courgette plants.
Because the important thing is, if you look at any plant
this is where
the action is happening. I call it "the business end", so sunlight, new leaves,
healthy,
equals growth. These leaves do most of the photosynthesis. I mean,
probably, from what I've read and been told, it's actually these leaves here, these smaller leaves right in the middle of the plant,
that are the most
active at
photosynthesizing and
enabling growth.
And so this courgette plant, just for example, there's quite a few of these younger leaves - all healthy. That, by the way, there's a natural
graying discoloration you get on quite a few cucurbits, and it's not the same as mildew.
If you want to check that something's mildew,
you turn the leaf over and you see how that's basically healthy if that was mildew, you'd see
discoloration and more powder, or - depending on the kind of mildew actually, I should just say, we're talking here specifically about powdery mildew,
this very white,
surface top growth more than underneath. And although underneath, it's not looking brilliant, that's related to it
but, you notice it most dramatically as the white top and
generally speaking when I see that I don't worry.
If it was in the polytunnel where I'm growing cucumbers,
I cut them off just so they're not in the way basically, but it's not like it's going to spread. This is a disease which,
it's kind of programmed to,
to dispose of older leaves, if you will.
It's not a disease which is going to spread, like potato blight say, which
does infect all- all leaves whether they're young and healthy or not.
This is a disease of older leaves and I'm very happy, if I was taking these leaves off,
I shall put them in the compost heap.
Because this disease doesn't spread like that. It-
Even if you had a brand new garden on virgin soil and you were growing courgettes, I'll bet you anything,
I mean, I've seen it here in my first year you get mildew. It just appears.
It's sort of spread by the air in late summer, mostly when you've got the leaves ready to decay.
And it appears and you don't need to worry. You'll see it on squash as well. Where,
as the fruits develop, and
they've done most of their growing, and then you'll see the -
most of the squash leaves starting to decay, and a lot of powdery mildew is involved in that stage.
And again, don't worry. As long as you're seeing nice healthy squash, it's natural aging of the plant before the final harvest.
Here we keep picking the fruits of the courgette, or zucchini, and
that makes the plant want to keep growing because it hasn't yet managed to make some seeds.
So that's where harvesting courgettes actually enables the plant to live for longer.
Because you keep taking the young fruits. And these will go on for probably about another month, and then they will die off.
Mainly probably killed by frost, and we'll just put them all on the compost heap. Mildew and everything.