Attacking my greenhouse bugs

I need a plan of attack...I have growing bins and in spite of using Encarsia wasps, the whiteflies have won. Not only that, I now have aphids for the first time--the tomatoes, zucchinis and peppers have been completely outnumbered. Last year the spider mites were bad but this spring, before I put any plants in, I attacked the top few inches of earth and all the bins with scalding water, and this helped somewhat.

Anyhow, to deal with the others, I thought I'd dig out all the growing medium and next year, grow only in containers. But this is an enormous job--about 170 cu ft of material to move out. Does anyone have any feel for whether this might solve my problem?

The greenhouse is attached to our main house, accessed through a door from our basement. It isn't heated and I can't move plants in there until April and must close it down by mid October each year (we're in a cold climate, long winters). I have large roof vents that are mostly open all summer, so flying critters can come and go but the whiteflies originated inside not out. I can't get the Encarsia or ladybugs in here early enough in the spring to attack the first whiteflies (and I can't figure out how they or the aphids winter, either.

Any suggestions at all will be appreciated. Sorry this is so long, but I'm desperate! I hate to go in there now; have to wear a toque and long sleeves. Ugh. On the other hand, if I don't have the greenhouse I don't have tomatoes, peppers or squashes--summer here is too cold at night.

Rosemary

Rosemary, I would suggest using a combination of control methods. See the mealybug thread for additional discussion. It sounds like biologic controls will not be effective for you.

As you know, spider mites love a dry, sick plant. Spraying the plant directly helps a lot with spider mites and mealies. Spray hard enough to dislodge the suckers.

Studies also show that moving the plant, whether it is manually (with your hands), with a spray of water, or with air movement from a fan, helps with pest resistance in the plants. Do you have HAF fans? Is the air moving all the time, 24/7? It should be.

Neem oil, 2T/gal, regularly.

Soap spray, but be careful. Tomatoes suffer phytotoxic injury from soap sprays with detergents. I have had better luck with soap spray made from baby shampoo, 2T/gal.

Sticky traps. These don't help a whole lot, but every little bit helps. This year I'm going to try sticky traps made from Tanglefoot spread on yellow paper plates. I've heard of using motor oil and other substances. You can buy sticky traps, of course.

Pyrethrin (pyrethrum) spray.

Have you thought about companion planting? I think it helps. Here is a link: http://www.attra.org/attra-pub/complant.html

Hi, stressbaby

I did get some Neem oil but too late for this year. I keep fans going all the day, but not overnight--aside from the fact it's very cold at night, we're on solar power and those fans are a drain.

Didn't know that about Tomatoes--I've been using Safer's. Is that a detergent? The squash leaves don't like it very much. Have also tried the pyrethrum. I

'm not sure whether I just didn't do enough early enough but nothing I used this year checked the nasties. I started out with sticky traps but they became overhwelmed and I switched to sprays.

I think I'll go ahead and empty out all the growing bins, and use scalding hot water on the frames, and then start fresh next spring. My outside beds will get a heavy layer of greenhouse mix and the accompanying bugs but hopefully the natural critters out there will be able to deal with any that winter.

That's a great idea, using yellow plasticized plates with the Tanglefoot. I've been putting it on yellow card but it's too absorbent. Warming the Tanglefoot first helps the application.

I grow Marigolds in the greenhouse--they do a good job of attracting spider mites!

Will check out the mealybug thread.

Thanks for all your suggestions.

Rosemary