My daylilies had rust pretty bad last year, so I was wishing for a very cold winter (won't do that again) to help kill it. I also started using Neem Oil with applications being done on May 4th, May 18th, and May 26th. I was hesitant to apply too often so waited two weeks between the first and second application. Yesterday I saw a little rust and decided to go ahead and put on the third application.

The product says it can be applied every 7 days, and to spray until covered, using 2 Tbsp per gallon of water. I did that with the first application and it took half the bottle before I was done spraying 200 daylilies and about 6 rose bushes.

Would like comments on how others use horticultural oil to control rust on daylilies, or even on other plants (I used it on my roses too). Am I using it too often? Too liberally? Can it actually do more harm than good to my daylilies? Should I be using something else?

This is only May and I remember that the rust really looked bad by the end of July, so I really want to be proactive and thwart any rust before it takes hold again.

I have never heard of using neem oil for rust. I know it is very good to control mites and thrips though.

I have never heard of using Neem Oil for rust either. Ok so I just googled it and it seems to be listed here and there as being used for rust but I don't know how old that info is.
Basically if your plant has rust and you choose to spray to control it you will need a systemic fungicide. If Neem oil is effective it is only as a contact fungicide which means it kills the visible spores ONLY. I'm sure someone will come along with a more advanced explanation but to keep it simple rust begins inside the plant long before you see it on the foliage and will lay in wait until the right environmental conditions appear. A systemic fungicide gets inside the plant and kills (hopefully) or at least suppresses the disease so it does not appear on the outside.

The only other way I have heard of ridding it (no guarantee) is to cut the foliage all the way to where the fan goes from green to white (rust lives in the green) and hope it doesn't come back. You have to make sure all the cut foliage and dead garden debris is properly disposed of (placed in plastic bag and tied up). This works for some and then others will spray heavily with a contact fungicide the cut daylilies and surrounding ground since the spores can hide anywhere.

Hope this helps

I have tried neem oil on several occasions and had no luck with it, for scale (on euonymus) or rust on daylilies. I have had limited luck using Daconil and Immunox combined (this is what I could buy at Lowe's) haven't been able to afford Cabrio or Headline, but so far still no rust showing here and it was bad last year.

Seedfork said:I have tried neem oil on several occasions and had no luck with it, for scale (on euonymus) or rust on daylilies. I have had limited luck using Daconil and Immunox combined (this is what I could buy at Lowe's) haven't been able to afford Cabrio or Headline, but so far still no rust showing here and it was bad last year.

We had a bad rust outbreak in 2012, and Neem didn't do a thing for it.

Thanks all. I guess I need to check into systemic fungicides if the rust gets worse. I was so hoping that the neem oil would do the trick because it is supposed to be organic, but am glad to know the difference between contact and systemic solutions.

I told my husband that if we have a drought this summer, we will not do overhead watering like we did in 2012.

Neem oil also kills bees.

I did try Neem on Sego Palm scale and can't say if it helped or not. Also used a spray made from coffee grounds that is supposed to help on Sego Palm scale.

Horse people use Captan on fungus and I may try and locate some of that to have on hand when and if rust shows up here.

Hi Vickie, I live in Georgia and have battled with rust over the last few seasons. I had some success last year after following some guidelines set out by Dr. Scott Elliott who grows and hybridizes daylilies near Savannah, GA. However, if you are strictly and "organic gardener," his use of chemicals will likely turn you off. I live about 150 miles northwest of Savannah and I usually see rust in the spring as temperatures pass from our winter cool weather to our summer hot/humid weather, then again in late September and October after temperatures drop back below the 85 degree mark with a much smaller amount hanging on during the summer. Scott wrote a 3 page paper in our Region 5 magazine early last year which described not only his methodology, but gave some background on daylily rust, its reproduction cycle and methods of control. It sounds like you are beyond the "protection from rust" stage, and possibly beyond the "remove infected plant tissue" stage that Tink described. Scott goes into considerable discussion regarding fungicides and how they are divided into contact and systemic, but also into how they are divided into groups based on how they actually function - - which brings him to a discussion of the the FRAC code (Fungicide Resistance Action Committee). This is extremely important because the use of a single fungicide or multiple fungicides which are from the same FRAC code may lead to mutations in the fungus and resistance to that class of chemicals.
Here are his recommendations:
1. Always use a mix of one contact and one systemic fungicide in a single application.
2. Systemics must be applied in rotation - that is, application #1 uses one systemic fungicide and is followed 10-14 days later with an application using a different systemic fungicide from a different FRAC code.
3. He suggests using neem oil not for any fungicide properties, but for its ability of coat the foliage, thus making it more likely that the contact fungicide will in fact contact all they pustules on the foliage.
4. He also states that pure neem oil must be mixed with an emulsifying agent before adding to the mix because like almost all oils, neem oil and water do not mix with each other. He uses a dish-washing liquid for this purpose. There is a pre-emulsified neem oil available on the market, but it really jacks up the cost.

There are some other things that he mentions, but these are the highlights. However, that still leads one to ask "Yeah, sure. That's wonderful, but which chemicals does he use?" Here is his list:
Contact fungicides: Cholothalonil (Daconil or equivalent) or Mancozeb (Dithane or equivalent)
Systemic fungicides: FRAC code 11:Pyraclostrobin (Cabrio) or Azoxystrobin (Heritage)
FRAC code 1: Thiophanate Methly (Cleary 3336 or equivalent)
FRAC code 3: Propiconizole (Banner Maxx or equivalent) or Myclobutinil(Systhane or eq)

The positive: I had pretty good success with a rotation of these chemicals (along with neem/dish soap) when applied every 14 days. No, it didn't kill the rust 100%, but it really knocked it back and it did appear to kill the rust on many of my daylilies.
The negative: The systemic fungicides are EXPENSIVE!!! Anything from code 11 is very expensive. Cabrio is the least expensive, and that is not to infer that it is cheap. It is not, it is just less expensive than Heritage. Code 3 products can be found in your local big box store. The code 1 products are harder to find unless you are in major metropolitan area and are willing to call a lot of specialty stores until you find it. The code 11 products are internet purchases for me.

I hope this helps, but it will probably depress you when you find the prices for some of the products. Do others in your area have a similar problem? I'm surprised that with the winters we all had this year that rust is already so noticeable in your garden. We actually got below 10 degrees a couple of times here this winter and had an ice storm that shut down this entire area for nearly a week (downed trees, electrical lines, etc.) and I know you had it colder and for a longer time than we did. Of course, we went from winter to summer with only about two weeks of spring. It hit 90 degrees the first time in mid-April and has been 90+ every day the last couple of weeks and rust does not reproduce nearly as well when the temperature is over 90.

Good luck,
Larry

I have followed Michelle's advice.

http://garden.org/thread/view_...

Thank you very much for that information, Larry. That is a pretty intense regiment, but if it works that's great! I am not averse to using chemicals that are not organic if they work, but oh my, the prices of some of those systemic fungicides scares me. I never gave any thought to rotating chemicals. We certainly don't want the fungus to develop a resistance.

I didn't think about adding dish washing soap to the neem oil, but it certainly makes sense.

I don't have very much rust showing at this time, just saw a few spots. But I guess I was getting paranoid already because of how bad it looked last July. I was hoping to avoid getting into that situation this year. I will have to check with some fellow daylily folks to see if they are having any problems. One of my neighbors has over 1000 daylilies, but we have never discussed rust. I'll have to ask her.

Thanks for the link, Glen. Michele rotates the chemicals too and has some good advice about cleaning up debris and getting rid of rust buckets. I already have a few that I think I will have to get rid of.

@Tink3472 I know you are very busy Michele so no hurry on this but I was wondering when you ever get some spare time (maybe on a rainy day) could you share your list of daylilies that are rust buckets for you??

That's a good idea!