Keeping whitefly away from the greenhouse...

I have heard of using French Marigolds as an insect deterent...not specifically for whitefly though... Same as pyrethrum daisies....Chrysanthemum coccineum dust as an insecticide.
If you want plants specifically deterent to whitefly my herbal suggests Nasturtium, peppermint, thyme or wormwood. Hope this is useful.

Chris Beardshaw told me (what a name-dropper!) that marigolds deter blackfly so I wouldn't be surprised if it does the same for whitefly as well

Black Fly...White Fly... lol... over'eer blackfly is a blood sucking insect that comes out of the swamps in great numbers in May...and has been known to drive forest animals mad... things sure are different continent to continent...

Hi Spritzhenry, Yes french marigolds grown in pots alongside tomatoes, cucumbers and Peppers will keep whitefly and greenfly at bay. Apparently it is the aroma from the scent which the aphids do not like. It has certainly worked for me so give it a go.

Thank you - let's hope it works! I am not a fan of French Marigolds planted in the borders, so the greenhouse is a good place for them to earn their keep! Sorry to hear about the nasty ones you get, Lori! Please don't send them over here.... lol. They might send ME mad!