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Question About Rust

We have barely had a winter this year. My daylilies all look great, but I read that with little or no winter, rust can get bad. I have no idea how to treat it if it occurs. I dont want to buy huge amounts of expensive treatment. Does anyone have advice for a hobby gardner to prevent or treat rust with products that I can get locally? Thanks for any advice....

Judith

Comments (21)

  • Ed
    12 years ago

    After this mild winter, if your daylilies look good, then congratulations! You probably don't have rust. You just need to try to prevent bringing it into your gardens. Isolate any new arrivals and make sure they don't have rust before placing them among your existing plants. When wandering through the flowers, always go to the newest arrivals last.

    To prevent rust, if you feel your gardens are susceptible to it, you might consider spraying. All of the fungicides that have proven effective against rust, are pretty expensive. My recommendation would be to check with Mark Carpenter or someone else in your area that sprays their plants, and see if he/they would sell you a small amount of Cabrio EG. If that's not possible, I would purchase the smallest amount of Nickel Plus, probably a gallon and spray with it. Last resort, buy a small container of Compass or Armada. All of the above can be top sprayed on the foliage, and will systemically protect your plants from rust infections. Try to spray after the plants have been watered, or a rain. But best if the fungicides are allowed about 48 hrs to be absorbed before the foliage is subjected to water or rain. Good luck, Ed

  • dementieva
    12 years ago

    Are you a member of a local club? If so, you can probably find someone to sell or share a small amount of Cabrio. Definitely the cheapest way to get something that works.

    And I'd also recommend starting before you see any rust. Prevention is a lot easier and faster than treatment of rusty plants. I've just about gotten mine under control after cutting back leaves and spraying for the last three weeks.

    Nate

  • Nancy Barginear
    12 years ago

    We had a nasty outbreak of rust last fall, continuing through the mildest of winters. We have once again begun spraying with Nickel Plus and K-Phite. We spray every week for three weeks, and then once a month. With Ed's recommendation (see above), I also ordered Cabrio EG and it should arrive this week. The Nickel Plus distributor recommended using Macozeb fungicide on a once-a-month basis also.

    The closest distributor for Nickel Plus, J. C. Smith Company, is located in San Saba TX (saves on shipping), and I bought a 2.5 gallon bottle for a little over $100. It lasts a long time, but just don't let it freeze or it solidifies. We made that mistake and while we still have plenty (of solids), I had to order some fresh. It can be reconstituted with water once all the liquid has been removed from the bottle, but it takes time and muscle to shake that heavy bottle until the crystals are dissolved.

    We used Nickel Plus and K-Phite when we lived up in Coldspring, and had great success with it. The rust just slipped up on us here in our new place, as I had gotten too complacent with thinking I had no rust here.

    If you get new plants, even though you separate them from your other daylilies, the wind can carry the (hidden) rust spores from a long distance. I'd soak any new ones in a 10% Clorox solution for 30 minutes before planting them. I didn't do that last fall, and now regret it. I knew better, too!

    We had very healthy seedlings that were planted about 200' feet away from the daylily bed, and separated by a high board fence -- and they eventually got rust too, though they were in no contact with the others. It might be best to use separate garden equipment on the new arrivals or sterilize your tools to avoid spreading the rust spores. You really have to treat rust like it's a dread disease. And even then, in this climate I'm not sure it will help.

    It would be good to get a head start on it, even if you see no rust. It will be at its worst in the spring and fall here in southeast Texas, when the nights are cool and the days are warm, with heavy morning dews.

    If you spray with these fungicides, I highly recommend you wear protective gear and a good quality respirator.

    Nancy

  • Maryl (Okla. Zone 7a)
    12 years ago

    I have just about enough energy, money and patience to spray my roses with fungicides occasionally. One of the reasons I grow daylilies is to enjoy a beautiful flower without all the disease problems that roses can be suceptible to. And considering that all the fungicides I use on roses have no effect on daylily rust, my pocketbook would suffer another hit. If daylilies became just another source for aggrevation I'm afraid something would have to give...I voiced these concerns when I first heard about the rust issue when first starting out in daylilies years ago and a very nice daylily person told me that to be on the safe side it is best to order from northern growers who don't have as much of a rust problem because of dormancy. So far, so good and there's no rust at my house-YET. However this post was a reminder to me not to stray too far from that original advice...Thanks

  • random_harvest
    12 years ago

    I agree, maryl. I don't even spray my roses. Alameda, I didn't have a smidgen of rust last year (too hot for it?) and I've been worrying about the mild winter also. My strategy is to plant no new daylilies this spring. When and if rust appears, I'll do what I've always done -- cut the rusty plant all the way to the ground and hope for the best. So far, it's worked. I have evicted a couple of plants that seemed to be rust buckets but others that have been infected and submitted to the cut-back procedure have been rust-free in subsequent years. Your mileage may vary.

  • alameda/zone 8/East Texas
    Original Author
    12 years ago

    Thanks for all the great advice! I have another question....I read somewhere that Daconil was effective for rust. I saw a spray bottle of it today, read on the back, and it does say its effective for rust. What about this as a temporary fix until I can acquire some of the above mentioned products?

  • Ed
    12 years ago

    Fungicides may be divided into two categories; contacts and systemics. Daconil (Chlorothalonil), is a contact type and must come in contact with the fungus to kill it. If you presently have rust, it would only kill the surface spores. Rust inside the foliage would not be affected much. Daconil could be used effectively by cutting the foliage off the plant, and then spraying the plant and area to kill any spores present that would re-infect the plant as the foliage grows back out. This is a workable method if you don't have lots of plants with rust. Mancozeb is another inexpensive contact fungicide that is effective. Contacts are more effective in a prevention scheme, rather than for eradication. Ed

  • Maryl (Okla. Zone 7a)
    12 years ago

    Just to clarify what I think I know (but might not), like roses, are some daylilies more susceptible to rust then others? And wasn't there a time before all the increased hybridization that there was no such thing as widespread rust or has it always been around on the wild species too?...Maryl

  • Ed
    12 years ago

    Yes, some daylilies are more susceptible to rust than others.
    Daylilies and daylily rust come from Asia. The bare rooted plants came first through Europe around 1900. The introduced daylily had no natural pests here and was called the perfect perennial. Till around 2000 when daylily rust was found on daylilies in a Florida garden. Some of the species plants are very susceptible to rust. Since then, we know there is an aphid that likes the daylily and recently, a small fly has selected the daylily to lay its eggs in and give us leaf miners. Spider mites also cause problems when things get hot and dry. Nothing stays perfect for long! I think the only thing we can blame on the hybridizers is crown rot, but they haven't made the other things better!
    Ed

  • Maryl (Okla. Zone 7a)
    12 years ago

    Here's where one of my rose care products does come in handy on daylily pests - leaf miner and Spider mites. AVID was originally intended to control leaf miners in Columbine (Aquilegia)plants. An additonal bonus to AVID was its killing effect on adult spider mites. For me, where spider mites infest everything from mini roses to Impatiens, it was a minor miracle when it first became available. The caveat is that resistance can build up and for many who sprayed AVID on a routine basis it soon lost its efficacy. Since I only use it when major infestations are looming on the horizon, I've not had that problem in all the years I've used it. A strong spritz of water is my first line of attack on Spider mites (and Aphids for that matter), but if the population begins to explode I reach for AVID. Some years I don't need it at all, but when I do it really works when the required intervals for spraying are followed (1 week, 1 week, 2 weeks)....And thank you for the information on the origins of rust and the daylily.....Maryl

  • terrene
    12 years ago

    I have seen references to rust over at the Lily Auction, but had no idea it was such a problem in southern locations. It's probably not a problem in zone 5/6, but does anyone know what zone is considered the borderline for rust being killed over the winter? Would Daylilies from a nursery in Tennessee have this problem, or do you have to go farther north than that?

  • Ed
    12 years ago

    Winter temperatures fluctuate, so there is not a hard answer as to what zone is free from rust. I put the boundary at zone 7, but there are micro climates and things an individual can do to help with the eradication of any rust, or to preserve it.

    In the spring, if nurseries or other concerns in northern zones import daylilies from southern gardens, there is the possibility that they are importing rust too. It may only affect you for the season if you are in a zone where winter kills the rust, but you must weigh the risk when buying from that business. I would recommend you purchase from concerns that have a good reputation and guarantee their plants.

    On the other hand, nurseries in zones 8 and greater should have more rust resistant plants to offer, as they will see first hand how susceptible their plants are. But again, it comes down to reputation as to whether or not they will be truthful in representing their plants.

    I hope this answers your question. Ed

  • floota
    12 years ago

    Ed,

    You are obviously knowledgeable about rust and how growers in the South - your zones- treat rust. There is a project that AHS is working on that I'd like to talk to you about.
    Can you please email me privately at :
    president@daylilies.org

    Thanks,
    Julie Covington

  • terrene
    12 years ago

    Yes thank you Ed. We had a zone 7 winter (i.e. lowest temp was about 2F) this year here where I live where it's normally borderline 5/6. Some of my zone 7 hardy annuals should come back this spring! But that happens every few years.

    How does the Daylily rust impact the plants growth in a year of bad infestation?

  • Ed
    12 years ago

    How does the Daylily rust impact the plants growth in a year of bad infestation?
    It really depends on each plants susceptibility to the rust. I have rated my plants using the following criteria:
    A. Free of rust even in heavy pressure periods.
    B. Moderate amount of rust spots on the lower outer leaves.
    C. Rust is apparent, but the plant will shed the rusty leaves as soon as rust season has passed. Readily responds to treatment.
    D. Very rusty, but the plant is vigorous enough to overcome the rust.
    F. Very rusty and the plants lacks the vigor to overcome the rust. Without intervention, in periods of high stress, the plant will die.
    Somewhere in the list, I think you will find your plant's reaction to the rust. Good luck, Ed

  • Maryl (Okla. Zone 7a)
    12 years ago

    There's a rust "season"? When should I be on the lookout for the first signs of rust? Right now I really don't pay much attention since all my plants go winter dormant, but this year I ordered a new plant from down south, and if it's infected I need to know when to start paying attention. What conditions are necessary in order for rust to germinate and infect other plants? In roses blackspot needs specific temperatures and moisture conditions to be a threat, is rust the same? Do high temperatures in summer stop rust. I'm learning so much about rust. I really do appreciate all this information......Maryl

  • Ed
    12 years ago

    "Your mileage may vary"
    LOL, how true!

    Hi Maryl, yes, like most things, rust has a season when conditions favor its growth. In this area, we usually have two rust periods per year. Rust grows best when temperatures are moderate, something like 50 to 70 degrees F and the foliage stays wet for several hours. Here, we usually have 80% relative humidity, so it's usually wet enough. As the temperatures rise in spring and fall in autumn, we see active rust. Rust usually subsides during the heat of summer. Zones with very cold winter temperatures will kill the rust or severely set it back. Most zones, like yours and north will only have one period of rust per year; in the fall. But if weather conditions favor rust and you have a very susceptible plant, you might see it in the late spring. I think the blackspot on your roses would be a good indicator, as I think rust needs much the same conditions to grow.

    To prevent rust from getting into your garden from new arrivals. Remove all green foliage from the plant, soak in a 5% bleach solution for an hour, rinse well and plant. Ed

  • alameda/zone 8/East Texas
    Original Author
    12 years ago

    Raspberry Winter seems to be the worst offender so far. I cut off all the folliage with rust on it but didnt get a chance to spray as the monsoon was on its way. Do I need to cut even the healthy folliage off and then spray? Will cutting off the folliage affect the blooms the plant will put out? I have Mancozeb in addition to Daconil. Which should I use?
    Judith

  • dementieva
    12 years ago

    I've been just watching this thread because Ed has better experience than I, but I thought I'd chime in on one point. You can buy from rust-free gardens and do everything in your power to keep from introducing it, but that won't necessarily stop rust from getting into your garden.

    If people are growing daylilies near where you live, spores can travel on the wind (just as they do for any fungus). You might also end up carrying spores from garden stores or other people who have been around daylilies.

    Long story short, don't feel bad if you are taking every precaution (short of fungicides) and still see rust in the garden. It just happens. Growing daylilies in the south in 2012 means either tolerating rust or actively eradicating it, but there's nothing to be ashamed of if you see it in the garden.

    Nate

  • Ed
    12 years ago

    Judith, the rust is inside the leaf in the green tissue. If you are to have a chance at eradicating the rust using only a contact fungicide, you must cut off all green tissue and then spray the new emerging foliage on a regular basis (every 3 days for at least two weeks) with the contact fungicide. Either Daconil or Mancozeb will work. I would then spray this plant weekly until around the middle of June, then wait and see if the rust comes back.

    Yes, at this time in the season, I think you will loose some bloom or the bloom will be pushed a little later in the season because of cutting off the foliage. Maybe you won't get rebloom. It's kind of a trade-off though, as a bad case of rust will certainly diminish the amount of bloom you will get too.

    As Nate says, rust is out there, just like bermuda grass and nut grass. To keep them out of your beds, it takes work and dedication. Ed

  • dementieva
    12 years ago

    Case in point -- I went to a Houston Garden Center today, and the entire Stella D'Oro section (the only type they normally carry) was rust infected.

    Nate