Diatomaceous earth may get some or all of them. It takes a little time but the results have been great for me.
No self respecting chemical sales people will tell you this as it knocks them out of a profit.

Here is a link that might be useful: Diatomaceous Earth

novascapes: How did you get the powder under the leaves and did you have hundreds of plants in your greenhouse? What kind of implement did you use to get the powder in air-suspension and to stick to the underside of the leaves? What kind of respirator did you wear and how expensive was it? DE should not be breathed in. It's very damaging to lung tissue.

I have DE and found it impossible to get into air-suspension. It's worthless on top of the leaves as these insects live and feed UNDER the leaves. At least it was cheap.....

Greenhouser, I had a similar experience the first year that I had my gh. I was so frustrated and angry that I spent so much money and time and lost many many plants that year. I was really sorry that I had the greenhouse and couldn't bring myself to go in there very often. A lot of my insect problems actually came from the plants I was bringing into the GH.

So called high quality plants purchased from first rate nurseries often were badly infested with every kind of pest. The only way to have prevented bringing in pests with them would have been to remove the plant from it's soil, wash in insecticide and repot in sterile potting mix. Oh, and the term sterile potting mix is certainly a misnomer, isn't it?

The second year was better after I managed to get insects under control by using a LOT of insecticides and constant monitoring and hand picking. But the moisture problem persisted even though I had installed an automated misting system. Then I had a whole other set of problems. We are on a well and the water is very hard, so the minerals built up on everything, burned out the swamp cooler, clogged the mist system and everything related to the water came to a screeching halt.

This year we had one of the hottest summers on record and the fans in my GH were working full time so it stayed warm but not hot inside. I turned off the automated water system and brought in a rain barrel. Oddly, the 60 gallons of clean rain water helps to maintain constant temp and moisture levels. The fans keep the air moving and that prevents molds and fungus from getting a foothold. The vents still open and close as they are regulated by the thermostat but I covered the inside of them with a fine screen that prevents new insects from getting in.

Having said all that I still spray for bugs and fungus almost daily as a preventative. I only use the kinds of sprays that are safe for food plants because I have my citrus trees in there and many of them are in bloom right now.

Greenhouser, don't give up after only one season. I kinda think of my greenhouse like a new garden plot. The first year the soil is not very good, but I till it and add amendments designed to attract earthworms. The second year it's better but requires lots of weeding and more amendments before it can support healthy plants. And so on for about five years before the ground is really fertile, rich and ready for a garden. There's a lot to learn about greenhouse management before you get it right and you shouldn't expect to learn it all in one year. Cheryl

I used an old antique pump blower and fan. I used a carbon filter mask.
I became acquainted with it because I had a sever roach problem in the house which the exterminators could only give me temporary relief. The diatomaceous earth took care of the problem. It has been over 2 years with out a problem. As far as the greenhouse is concerned, just totally fog it. The next day there are no more dust particles to worry with. Unless you wash everything down the DE should last a very long time.

Maybe you started out too big too fast? You're retirement project sounds like a nightmare. work with what you CAN control and expand only as you feel you are in control.

Clean the gh out and restart with just a couple of plants.

I agree with seamommy... bringing plants into your gh untreated is perfect for bringing in new pests. Been there, done that!

Oh yeah, that was something I forgot to mention, Cleaning! You've gotta take everything out of your GH at least 2-3 times a year and seriously clean everything down with bleach and soap. Mold and fungal spores are everywhere, as are insect eggs and larvae. Making your GH as inhospitable to them as you possibly can is the best way to control them. Once they're in your soil and on your plants it's too little and too late. And anyone who has had a GH for more than a year and claims to not have any problems with it isn't telling the truth.

I researched GH management and had logged into this forum numerous times before I got mine, but didn't find a whole lot about all the problems I've had the past three years. Most of what I've had to deal with, I learned the hard way, just like you are Greenhouser. But you've got the GH now so you might as well take another whack at it. Everyday when I walked past mine when I was stymied by the problems it was like the GH was looking at me saying,
"Nanner-nanner!!" I felt totally beaten it. So one day I decided to arm myself with Clorox, detergent and scrub brush and take back my territory. Still not perfect in there, but better. Much better.

A note about cockroaches, if you have scorpions they'll keep the cockroaches in check. You just have to watch out for the scorpions. Their sting is kinda like getting zapped with an electric cattle prod, but you can take away the pain by soaking your stung part in 2% peroxide solution. Cheryl

I guess everyone has different experiences. I've had my greenhouse running for 5 years and have never felt a need to specially clean it, and I have never had a pest problem...other than the occasional slug. It's well-ventilated in the summer and it is minimally heated (about 40F) in the winter, and that's it. Maybe I should consider myself lucky because I sure don't use any special strategies or techniques.

To: Seamommy

I had my greenhouses for several (about 5) years. This wasn't my first year. I worked in a greenhouse in NYC for several years some time back. The first year was OK. All plants were checked for insect pests before I put them in the GH. The second year and third year are when the insect problems started. This past summer was a nightmare. The insects today are almost totally resistant to anything a homeowner can buy. :*( And they're all quite expensive. Years and years of farmers drenching their fields with insecticides helped make insects and bugs resistant if not immune. Just like antibiotics are no longer working as well with bacteria. My Ag agent worked with me on the problems and admitted he had no answers after the first year. The stuff that works isn't sold to non-farmers. The whitefly were even immune to systemics. They killed off all my beautiful poinsettias. Even my outside veggie garden was attacked by the whitefly as the young plants came up in the spring. They spread from the GHs. The mealy bugs were the last straw. They finally killed off my gorgeous prayer plants and rose flowered begonias and impatiens. I managed to save two plants by cutting them down to the soil level in their pots and bringing them into the sunroom in my house. They were drenched in systemic. Meanly bugs too have almost total resistance to every insecticide a home grower can buy. Trying to clean loads of large plants with alcohol on a swab can't be done. My greenhouse windows were made in such a way that they could not be screened and there was no way to screen the large doors. So the insects from the GH spread to the outside gardens.

Humidity was always too high in the Rion. 6 fans ran fulltime or on timers. Auto vents opened and closed. One large fan one was the rotating type. Ventilating the GHs to keep the humidity down caused the heating bills to be unaffordable. In summer the plants were outside. The summer heat here in TN would have cooked them in the GH no matter how many fans or vents were open.

The rest of the plants are in my sunroom and the GH is closed and covered. I'll choose a few that the insects wont't infest such as the snakeplants,... and as anything else proves to be infested after a drench in systemics, will be gotten rid of.

To: novascapes: I have no access to antique pump blowers for the DE. How did you get the DE to stick under the leaves of the plants? My GH was totally fogged more than a few times. That doesn't work either because I can't buy the insecticide fogging chemicals a Lic exterminators or farmers or GH business owners can buy. It's not sold to hobby GH owners.

There is no way to fog the GH with DE.

poppa: They were treated. Only a very inexperienced person would bring in untreated plants. The problem is the common insects/bugs are almost totally resistant to all the insecticides non-professionals can buy.

seamommy: My GHs were thoroughly cleaned twice a year. In spring when the plants went outside and in the fall before they were brought back in. Maybe I should have mentioned all these things in my first message. Even if I could autoclave the GH, there is no way to "sterilize" the plants.

I didn't start out big. I started with a few plants at a time and worked my way to a full GH over the years. :)
I'm not that wealthy to fill a 8.5 X 16' GH all at once.

Summers here are too hot to keep plants inside GHs. I know all these things about cleaning already because I worked at a place called Garden World in NY for several years. But they had the type of insecticides that work and would fumigate/fog constantly. They were a regular business. Plus I did a lot of research before buying the GHs. The smaller one I started with was a HF 6X8' GH. The Rion was added a year later. There was never a problem with excess humidity with the HF. I don't know why.

kudzu9: You've been very lucky then. These insect pests did not exist here where I live before I got the GHs. The only pests we had were squashbugs, tomatoe hornworm and cabbageworms. They were controllable. My flower gardens never had much of an insect/bug problem. No spraying was needed. Now I can barely grow veggies because the spider mites and white fly, both uncontrollable, spreads from the GH to the nearby gardens. The mealies were a GH problem only. They didn't spread to the outdoor gardens.

Before I bought the GHs my plants were in a sunroom in my house. Not as many of course. They spent the summers outside on a large porch. No problems for years.... until they all went into the new GHs. :(

Greenhouser,

So sorry to hear of all your trouble. That sounds like a terrible experience, especially because this was meant to be something fun and relaxing and has turned out to be the opposite. I can imagine not wanting to visit the greenhouse knowing there would be more pests to greet you - what a bummer!

It sounds like taking a breather is an excellent idea. You can stop pulling your hair out and take up a more soothing hobby like chainsaw juggling or cliff jumping. :)

Hang in there and enjoy some down time.

Karin

Greenhouser,

The microenvironment of a greenhouse varies widely, thus you have recommendations which vary from empty the GH (I've not done that in 6 years) to spray daily (maybe every 3 weeks for me). It takes some time to figure things out.

It is incorrect to state that summers there are too hot to keep plants in the GH. There are posters on this forum that keep plants in the GH over the summer in zone 8. I am in zone 6 and have plants over the summer in the GH now for 6 years. This summer, I had no misters, no fogger, only shade cloth and a fan, they did fine.

Next time, if there is a next time, consider neem oil for pests. There is no resistance to neem oil, this is well documented. It takes 2 weeks or so to work.

In the end, it is not a hobby for everyone. Best of luck to you in your next endeavor, I hope you find better success.

Robert

One spray about June 1 of the active ingredient in Avid or Florimite has given me year long control of spider mites. The reason I say it that way is I have the same active ingredients in other materials cleared for fruit. That's the only real pest issue in my greenhouse. Those materials are like the hammer of thor on my mites. Five warm months after they show up and 100% control, pretty amazing.

I keep my greenhouse as dry as possible by heating only to 34F in winter and running large exhaust fans in summer. I think this reduces pest issues. But I'm growing fruit not ornamentals.

Greenhouser, sorry if I came off as if you were completely new to the GH. I didn't realize how much experience you've had (significantly more than I have) and how long you had been into it. Suffice it to say, as a fellow GH owner, I really do feel your pain.

I am also retired and enjoy puttering around out there in the GH, but if it was my only hobby it wouldn't be enough. I also sew, quilt, read, and restore and sell antique furniture. That way if one hobby gets frustrating, I quit it for a while and do something else. I do wish you luck in the future with the GH, but heck, if you decide to chuck it, that's ok too. Life is short. I retired after I was diagnosed with cancer for the second time. I am currently cancer free and plan to use every day that I have left to find as much enjoyment as I can. Life's too short to do anything that makes you miserable. Cheryl

karin_mt:

Yes, I'm taking time off. I'm mentally exhausted with the GH problems. All the remaining plants are in the sunroom where I can watch them all very carefully. If I have to get rid of everything, I will.

stressbaby z6: My GH goes up to 130F on a sunny day here in middle TN w/vents open and fans running. Even if the plants could cope with the heat, there is no reason to keep plants in it. I have over an acre of land and they do much better outside under the trees or on the dappled sunlit porch.

I used Neen oil. That was one of the 15 products I bought. I tried several organic pesticides - none worked. In desperation we used it at almost twice the recommended strength and it still had no effect on the whitefly, mites or mealy bugs. Only the systemic worked, for awhile, but can't be used on food plants. To keep the mites in check I have to use the systemic weekly but it doesn't do much for the whitefly anymore and has little effect on the mealy bugs. Our Ag agent told me the insects and bugs are developing strong resistance to all these OTC insecticides. Our Ag agent did the best he could for us. When there is nothing left that kills the pests.... well, there is nothing left to do but admit they won and get rid of their food supply = the plants.

stressbaby z6: My GH goes up to 130F on a sunny day here in middle TN w/vents open and fans running. Even if the plants could cope with the heat, there is no reason to keep plants in it. I have over an acre of land and they do much better outside under the trees or on the dappled sunlit porch.

I used Neen oil. That was one of the 15 products I bought. I tried several organic pesticides - none worked. In desperation we used it at almost twice the recommended strength and it still had no effect on the whitefly, mites or mealy bugs. Only the systemic worked, for awhile, but can't be used on food plants. To keep the mites in check I have to use the systemic weekly but it doesn't do much for the whitefly anymore and has little effect on the mealy bugs. Our Ag agent told me the insects and bugs are developing strong resistance to all these OTC insecticides. Our Ag agent did the best he could for us. When there is nothing left that kills the pests.... well, there is nothing left to do but admit they won and get rid of their food supply = the plants.

This has been a terrible and expensive disappointment for me. Maybe after a season or two I can try again. But the Ag agent said if these resistant "bugs" are surviving in the surrounding plantings, lawns and gardens, they will soon be right back in the GH. :*(

We have a lot in common. I was also treated for cancer in the recent past and am now cancer free. I also do some sewing and have several garden ponds. I love to read. I garden. And we have an RV and travel. Now with the GH closed up, we're going to FL for a few months after Christmas. I will pay a relative to come over weekly to water what's left of the plants and check on the house. We will take our three cats with us. :)

fruitnut z7_4500ft:

I haven't seen that product (Avid or Florimite) here locally. At this point there are so few plants left, I don't even feel I want to try yet another product when nothing suggested on the forums or by my Ag agent worked. I bought everything people suggested. I have a huge carton here of pesticides that don't work. There was a product called Kelthane years ago that killed every last mite with only two sprays. It's off the market now.

Because of the 30 orchids, I had to keep my GH at a minimum of 55F. I sold them all the other week and cried when they went down the driveway. One of the cattleyas was bobbing it's beautiful flower as if it were waving goodbye. I had put so much time and care and love into them. They were all in bud or blooming and some I had for years. :*(

I knew if I tried to keep them the mealy bugs would get to them in time and I would have lose them all anyway.

Hey Greenhouser. I know you have more experience than me, but thought I would add my 2 cents. I had a bad problem last year with fungus gnats in my house because of plants that I brought in because it was to cold in my gh. I took most of the winter to get rid of them, and at first it did seem nothing was working, but with time I did get them under control. My problem was I wasn't killing all stages of the insects, so I would think they were gone, but soon enough they would be back. This was only with 6 plants and boy it was a headache, I could only imagine what you are going thru.

As for the heat issue in summer, I have the same issue here. There are only 2 or 3 plants I can leave in the gh b/c even with fans I'm lucky to keep it within 10 degrees of outside temps. When its in the 90s outside alot as it was this summer nothing likes to grow. As stressbaby said tho it can be done. A little shade can go a long way to block heat from your gh. I personally think it is more efficient on the outside so the heat doesn't make it through the gh walls. I am waiting now for a poplar tree to get tall enough that it will shade my gh in the early afternoon, at least I'm hoping it will. My friend has deciduos trees around hers for shade in the summer and sun in the winter. It works well for her, but she is oriented N to S, and my gh is W to E, boy does that make a big difference in all seasons. Good luck with ur problems I hope you get it figured out b/c its no fun havin a gh that you cant grow anything in.

Greenhouser, I hope you are still reading. You wrote:

"As you may recall I bought every insecticide people recommended save one... too expensive with no guarantee it would work any better than those I already had. I used both chemical and organic sprays and powders. The infestation consisted of white-fly, known to resist almost every spray out there. Spider mites that were also almost totally resistant. Then mealy-bug joined in the feast. "

And then you wrote:

"Our Ag agent told me the insects and bugs are developing strong resistance to all these OTC insecticides. Our Ag agent did the best he could for us. When there is nothing left that kills the pests.... well, there is nothing left to do but admit they won and get rid of their food supply = the plants."

I say baloney.

The one thing you didn't try that's guaranteed to work is to invite in the natural predators to your bug problem.

By using all these sprays and such, you're ensuring that will never happen.

I live in Central OH, with a large greenhouse. First year last year, and by September, bugs were everywhere. Since it's not heated I knew eventually the cold would get them, but the eggs and lava would be back next year.

And then the frogs & toads showed up to the feast.

With a week to 10 days, the bugs were unnoticeable.

I should note that I use no pesticides or insecticides. I am not strictly organic, but I know enough to know that what your AG said first -- that they're gaining resistance -- will only mean eventual immunity. I just disagree with the AG's concept of defeat.

And, the toads are still around. They like being underground of all places (probably all the manure!), but they peek out from time to time when I am in there. I also find them hiding under the strawberry leaves :)

And no bugs.

Remember, everything has a natural predator. You just need to determine what it is.

Mike, that is an interesting finding. I have tree frogs and toads in my greenhouse, so I may have to reinterpret my findings over the past 6 years in light of your comments.

My first couple of winters were terrible. I found that I had to spray almost weekly with neem or other synthetic pesticides to control whitefly, scale, mealies. By chance, frogs and toads made their way in. I did not deliberately put them there. Over the past few years I have found that the need to spray has reduced significantly. Now, I may spray generally with neem maybe once every couple of months and I hardly use the synthetics at all.

I thought I was getting smarter about surveillance, air movement, or plant choices. Now you have me wondering if the reason I don't have to spray as much is just because of my frogs and toads!

One note: if you have toads and you have ground beds (as compared to only containers) be careful in the winter with a trowel or shovel. They like to bury themselves in the soil :-(

Robert

Thanks for the tip about the shovel. I have noticed they like to be undergound (the surface holes give them away).

Since we're all raised beds (~12") pretty much everything is just pulled up by hand, no digging.

This last weekend, I noticed a fly in the greenhouse. It was sat on the leaf of a young pea plant. I saw a small motion out of the corner of my eye which revealed a surfacing toad. You can guess the rest!

Poor fly never stood a chance...

Where I lived two years ago, we developed a seemingly large population of toads. I thought they were awesome. Its like playing frogger trying to miss them with the mower though.

tree frogs are great!! Even before I had finished my new GH in August, the spiders moved in. Now I'm not a big fan of spiders, but knew they were good for the GH and I was trying to be cool about having them around....

The first thing I planted was cucumbers - just the plain old pickleing ones I had in the garden. The garden cucs were absolutely full of adorable green frogs and I wanted to make a habitat for them in the GH. Unfortunately by the time the new cucs were big enough to make a home for them, the frogs had all disappeared. I finally found a little grey mossey tree frog on an eggplant and promptly introduced him to the GH cuc plant. He made himself right at home, and sometimes now in the middle of winter I hear him singing.

My concern for the frog was what he would eat. Figured he would hybernate, so did not worry too much. The only insects are the night ones attracted to the lights who fly in when I open the door in the evening. Those get caught pretty fast in the spider webs. Now I have noticed a strange thing. There are spider webs, but no spiders in them. Guess that is what froggie has been eating. I'm definately ok with that.

You can bet there will be more than one frog in the GH as soon as I can find them again.
Carol

my son is a biologist/botanist. he grows carnivorous plants as a hobby. he named certain ones that could help in the greenhouse by 'eating' the pests. sundews? not pitcher plants and not venus fly trap. one other one can't remember. you might try looking for info on that. I second the natural predator theory. My parents always sprayed and chemically treated everything. I never did and didn't have pests to speak of in New Orleans area and now in north MS. I strongly believe in the toads, frogs, spiders, and in the rest of the yard the birds eat a ton.