how to avoid getting whitefly in the greenhouse

Sarah talks through her multi-pronged attack method of how she has eradicated whitefly from the greenhouse this year, using companion planting and encarsia packs.

Last year we had a really bad problem with whitefly in the greenhouse and it was just so depressing, you walk through the greenhouse and whenever you went like this to any plant there was this plume, a cloud, of these little aphids. So much so that we actually had to take the tomatoes and the cucumbers out in early September, which is just such a shame and such a waste.

So this year we were determined we were going to absolutely avoid any chance of whitefly. So we've gone with a multi-pronged attack and it has worked. I'm just so excited that it has worked because we really thought we weren't going to get on top of it.

The first thing is that we clean the greenhouse really, really carefully in the winter. We didn't quite use Jeyes Fluid everywhere, which traditional people will tell you to do, but we took everything out, all the plants, everything, completely emptied it and fumigated it with sulphur bombs. That got rid of anything that might have overwintered, things like red spider mite and white fly.

And then we started very early in the year with companion planting. We started with things like marigolds, the calendulas, in here, later moving to the half-hardy annual companion plants like the tagetes. This variety is called 'Tall Scotch Prize', which I love as a cut flower too. There's another beautiful dark red ochre one and a sort of mahogany colour, which is called 'Linnaeus', which we've got in here too.

And, if you look at the base of the plants, you'll also see there's basil, and basil is another really good companion plant because if you're going to get whitefly it loves basil so much it tends to go for it first and then, it's a bit of a shame, but you can just take out the basil and get rid of the whitefly. Whereas, you know, I don't want it to get onto my peppers because I've already spent lots and lots of months growing them.

So companion planting is really important, having a really clean environment is very important, and the third and final thing is biological control. If you look on the plants what you'll see is these little medallions, paper medallions and these arrive in the post, it's the encarsia wasp. They're almost so tiny you don't even notice them, but they will eat the aphid larvae and really keep on top of it, and genuinely now I can go like that anywhere in the greenhouse and there's just not a whitefly to be seen.

you might like