Kitchen Garden Forum

As a result of the Whitefly onslaught along with the usual pests I have suffered this year I have decided to set aside a bed for beneficial flowering plants. The bed is approx 20ft X 4ft and has 8 cordon apples down the centre.
Suggestions for plants to attract predator insects would be appreciated.
Ideally I would prefer perennials and common names.

Ken

Hi Ken

Sorry to start on a disappointing note, but brassica whitefly have no natural predator in the UK - unless you count this http://www.rhs.org.uk/Gardening/News/Wh ... ound-in-UK
As for the other pests, what you attract depends on what the pests are.

I read somewhere that parasitic wasps and lacewings are predators of whitefly?

Ken

I don't know about predators of brassica whitefly but the following flowers certainly attract lacewings and lots of other insects: poached egg flower (limnanthes douglasii), phacelia, plain pot marigold (not the modern varieties). All three will seed themselves prolifically if you don't cut them down after flowering.

I would add that I'm also aware that beneficial planting would also include plants that deter whitefly and other pests. It's not just about predators. I suppose what I'm looking for is a bit of natural ballance to aid conventional treatments. I will be trying something called "SAVONA" as a spray I don't know if any of the forum members have tried it but would be interested to hear.

Ken

Ken65 wrote:I will be trying something called "SAVONA" as a spray I don't know if any of the forum members have tried it but would be interested to hear.

Savona's been around for some years now and it's quite effective. It's basically a soap-based insecticide that works by fouling the insect's respiratory system, effectively smothering them. All insects are killed by it, so predators as much as pests are not spared. It is not systemic, so it needs to be continuously re-applied, and it has to be applied directly to the insects so it cannot be used prophylactically. It is washed off by rain. It does smell nice, though, and it's harmless to us.

One way you could attract a wide range of insects which could be useful as predators and pollinators would be to establish a herb bed, that way you would still get some use out of the area. Most of them are perennials like Marjoram, Mint and Oregano but self seeders like Borage and Chives would be low maintenance.

We've used soft soap spray when we have noticed the whitefly homing in and it seems to have kept them down - although we haven't had as many this year as previously so I can't say how effective it has been

Tried the "Savona" yesterday, looks like first contact reduced the whitefly population by a significant amount, probably more than 50%. I will persist with more treatments to see if I can reduce it to a manageable level. Down side is probably cost, at £25 a litre. Initialy I mixed at 50-1 the maximum recommended but I might try a slightly weaker mix next time.
Like the idea of Herbs also wondering about Lavender and Rosemary.

Ken

Both excellent bee attractions.

It wasn't meant to be a complete list Lavender and Rosemary would be fine as would Sage and Thyme.
A heather bed could be another idea, a mixture of Spring flowering Ericas and Autumn flowering Callunas would support insects at both ends of the season. You could mix these with the non-culinary low growing Thymes.