Hi Jim,
Thank you for replying back. Up until last year I just had the usual and occasional problem with aphids but now they have found me. I've read that keeping a greenhouse free of bugs can be a real challenge which is why I was interested in hearing how you handle it.
I'm pretty convinced that they each have their desired delicacies and there are about 5000 types of aphids so I'm hoping the ones that like tomatoes aren't in my neighborhood yet. And I learned first hand that they can easily live when temps are below 32* and above 120*. Bummer.
My fruit trees are also 3-4 years old. And I like your suggestion about planting yarrow to repel the aphids but....the year before last ants kept bringing the aphids to the trees so I planted lots of tansy (perennials) around the base of each of them. It didn't work at first until the tansy got to be about 3-4' tall and really bushy but it seems to work pretty well now at repelling the ants. Last summer I only saw ants once on just one tree out of 20. And it had a second benefit of providing cover for the trunks so they don't get sunburned and I don't have to paint them white every year.
But I still had aphids in the tops of the plum trees, they start at the tips of each branch. Turns out most aphids can fly. Imagine me pulling my hair out. Yes, I've heard of kaolin clay and I'm thinking your suggestion would be a good one to try this year. True, it's not pretty and I'd have to buy a new sprayer but definitely better then chemicals!
3 years ago I tried planting lots of nasturtiums in 1 gallon pots. They say aphids love them and to use them as a trap crop. So when a plant like my artichokes or cucumbers got infested I would bring over pots of nasturtiums and surround them trying to draw the aphids away. It never worked which is just one reason I'm convinced each species of aphids only likes certain plants.
But I'll look into planting yarrow in some of my other beds. It's worth a try. Thanks for replying back to me.
