Rust, Not much of an issue for a northern garden right? We get a reset button each year...
Enter the evil overwintering machine we call a greenhouse... Cue the scary music... Hide the kids, maybe the cats... leave the dog...
So yeah, thats what its like talking to someone about rust that has a greenhouse.. So Let me start this off by saying this.
I PURPOSELY PUT RUST IN MY GREENHOUSE.
Don't do this.
Why Did I?
Well, I figure at some point, no matter what I do, and how I do it... I will get rust in my greenhouse. So I did this to figure out a plan of eradication or control.. testing different products, figuring out what does and doesnt work.
Let me start this by saying, I had a failsafe here. Everything is coming out of the greenhouse on Nov. 5th and getting chilled outside till late december, anything Evergreen that I won't be doing that too will have all the foliage removed and dipped, with 2 follow up systemic sprays. I knew I had an Out... The greenhouse will be washed down with a bleach solution, and contact fungicide to prevent any rambo like spores from sticking around.
I also did this because I have heard about 15 different ways to deal with rust. And realistically everyone will have their pet choice of product for control.
So what's my plan? Well Lets go over the chemicals I have and use.
Heritage 50DF- Class 11 Fungicide, Systemic, 50% Dry flowable
(4oz version is now discontinued, get it while you can, next size is 1 lb)
Cabrio EG- Class 11 Fungicide, Systemic, Dry Flowable
Daconil- Contact Fungicide, liquid concentrate
Daconil Ultrex- Contact Fungicide, Dry Flowable
Green Magic- Contact Soap, Proven to remove spore by contact
Dithane- Contact Fungicide
Myclo 20ew- Contact Fungicide
So those are all the fungicides I own that I have used to combat rust. I am going to share with you my most effective means of rust eradication.
First things first, Spray schedule. 4 to 5 days MAX. Do not spray before or after.
All products other then green magic need a STICKER, half teaspoon of REGULAR DAWN works just fine.
I spray two mixtures.
Mixture #1 Heritage and Daconil Ultrex- .3 Oz of Heritage to 4 gallons, 2 teaspoons of Daconil Ultrex to 4 gallons.
Mixture #2- Cabrio and Dithane- 2 teaspoons Cabrio, 2 teaspoons Dithane
I also use green magic and or daconil liquid as a separate spray if I feel that I am effectively killing the rust in place of a mixture spray.
Spray #3 Green magic Or Daconil- Daconil Liquid concentrate 2oz per 4 gallons, Green magic 16oz per 4 gallons.
So I use Mixture one to start, 4-5 days after I rotate to mixture two, I do this on 4-5 day intervals for as long as needed. Once Rust is no longer visible, I will Spray like this Mixture one, then Green Magic by itself 4-5 days after, then Mixture two 4-5 days after. So you are effectively spacing the fungicide use to 8-10 days. I ELIMINATED rust in my greenhouse doing this. I did this for 4 weeks, All of september and the first week of october. I then stopped spraying. In 4 weeks in what would be the most favorable rust conditions, I have No rust, No spores, just spore scars.
YOU MUST COAT THE WHOLE PLANT.. DO NOT LEAVE A CM OF THAT PLANT DRY.
This is only My experience.
I feel confident, If I get rust, I can get rid of rust. I will also attempt to obtain "Headline" but its cost is about 800 dollars for 2.5 gallons. And I have no idea what Id do with 2.5 gallons. The active ingredient in cabrio is the same as in headline.
Don't spray Myclo without a mask, dont re-enter for a long time. I dont suggest its use for these reasons, Its nasty.
I will also say this Daconil Ultrex is WAY more effective as a contact fungicide then regular daconil.
I will still strive to keep rust out of the greenhouse, I will trim foliage, dip plants, and proactively spray new arrivals no matter where they come from with systemics. Just because you can get rid of it, or feel you can doesnt mean you should.
I also dont recommend this for spraying in your garden, the mixture of fungicides, chemicals, and cost are all big reasons to keep this method small scale, this is also probably a big reason why big commercial gardens dont use these chemicals or methods. The cost per 4 gallons of spray is pretty low Heritage is the most expensive out of all of them (Roughly 7 dollars per 4 gallons, or .3oz per 4 gallons).. But the buy in cost of the daconil ultrex and cabrio can be off putting. Both those products will last you nearly forever.
Now you all know I'm crazy... I put rust in my greenhouse on purpose.. I didnt wait for it.