Help - Greenhouse Whitefly/Greenfly

[inearlygaveup]

Just found some Whitefly & Greenfly on some of my early Greenhouse lettuce.
I cleared the lettuce's out but need to be sure its clear before I fill it with all my new seedlings that are begining to takeover indoors.
Glad I found it today before putting any new stuff in.
Any advice please on the best way to totally clean it of any remaining pests.

[jools]

I'm hoping you get some good advice here! I had the most awful problem with whitefly last year - I just couldn't get rid of them at all. Apparently, it was a really bad year. My own view is you have to make sure you wipe them all out - every little blighter. I spent a few weeks at the end of last year spraying the stuff I was overwintering and squishing any I found on the plants. I know I have killed most of them but I routinely go through the plants turning each leaf over and squishing the odd one or two I find. I have heard that basil and marigolds help - but I had basil in my greenhouse all last summer to no effect. Keep killing them is my advice and do it now before you put any more plants in there.
Jools

[Galileo]

Anne Swithinbank in her Greenhouse book says that

"Growing French or African Marigolds will ward of whitefly (In a Greenhouse) only if you have never experienced them. She says....

"I kept them out of my greenhouse for years this way until one year I lapsed and whitefly took hold."

They probably still help though. Or perhaps you could start fresh and clean down the Greenhouse and all the plants.

Galileo

[inearlygaveup]

Hi and thanks for your replies, I also use African Marigolds during the season and find they work very well, I didn't have much of a problem last year but these must have over wintered in the greenhouse.

I found a thread on "Sulphur Candles" started last May.
Alison gave this useful info ............. http://www.growfruitandveg.co.uk/gra...les_16671.html

Basically they fumigate your greenhouse, you don't have to use them but I find them a good idea at the start of the season to make sure that I don't have a house full of undesirables.

So hopefully I will be picking one up tomorrow and will smoke the little blighters out.

[matthew2riches]

It might sound funny but I smoked out the greenhouse with a smoke machine what I use for my mobile discos. It worked...........for a little while :-(

I have seen sticky traps that attract the fly to them and they get stuck.

[jools]

The only thing about sulphur candles is you use them in an empty (I think) greenhouse. Whitefly don't hide in the nooks and crannies of the greenhouse - they are usually on the underside of the leaves of the plants. Last summer I emptied the greenhouse of all the plants twice (no mean feat as I was growing plants to sell at my kids school fair!). I sprayed each plant and looked at each one carefully to make sure no whitefly were there. Didn't make a bit of difference. Went away for a week and the greenhouse was completely infested when I got back. I'm trying the belt and braces approach this year - doing the watching and squishing and sometimes spraying bit now, then will introduce marigolds and basil. Already have the yellow sticky fly traps hanging up. Will try any sort of sulphur candle you can use with plants in situ. What about venus fly traps????
Jools

[Duronal]

i've just discovered white fly on my over wintering gazinas, is bug spray the only way to get rid of them?

[inearlygaveup]

You could try it - there is a very good artical on whitefly hear GardenForum Horticulture: Pest Patrol: Whitefly

[Norm]

I think the greenhouse has to be empty before you use the sulphur candle. Guy on our lottie used one a couple of years ago in a greenhouse full of seedlings and came back the following day to find the aphids dead along with all his seedlings. A mistake he won't make twice!

[digthatchick]

I think the greenhouse has to be empty before you use the sulphur candle. Guy on our lottie used one a couple of years ago in a greenhouse full of seedlings and came back the following day to find the aphids dead along with all his seedlings. A mistake he won't make twice!

Yes you are definately right - Just set sulphur candle in mine tonight, it does state that NO plants must be in the greenhouse at the time or for 12 hours after.

This is a good link - http://www.rhs.org.uk/Advice/profiles0500/whitefly.asp