Right now I'm going through a purge of rust-stricken daylilies, most of which are in pots.

My question is, after prying out the plant, and removing as much dirt as possible (the trash company does not want dirt sent to the dump), is this dirt going to be forever infected with rust? (I'm presuming there must be *some* rust, from the surface layer at least... though by the time I am done getting dirt off the daylily roots, I have to view the entire pile as suspect.)

Is there any way to "reclaim" it, short of drenching it in bleach or fungicides (neither of which I am willing to do)? If the dirt sat in a bag and dried out for some amount of time (days, weeks, months, -?), would the rust spores all eventually die?

Any help?

They should eventually die, but it's difficult to say how long it would take. In theory they may die more quickly if they are not dried out. If there's not a huge amount of dirt, you could try pasteurizing it if you want to use it again soon. Even if spores did survive in the dirt, they can't do anything unless they get rain-splashed or blown onto green daylily tissue.

Did the rust come with the plants, or did it just show up? If it came in on the wind from somewhere nearby then there's not going to be much you can do to stop it coming back.

Putting the soil in a black plastic bag and sitting it in the hot sun for a couple of weeks should kill the spores.

Thanks for your answers.

I've tossed a lot of potted plants, so it is a lot of dirt - and in any event, I'm not sure how you would "pasteurize" soil.... heat up wet soil in the oven or microwave? DH would probably take a dim view of that, even if I didn't. I guess I will keep the dirt in the black plastic bags (where it currently is) and wait for summer to bake it.

The rust may have come in from some new plant or other, and spread from there. The first and last time the garden was this badly hit was in 2006, and I went through a rust purge then, getting rid of most of the susceptible plants. (I did keep a few for one reason or another; oddly enough, I have not seen rust on those plants since then. They are in a different part of the property than the current problem area.) Although we don't get cold winters here, thankfully the weather is usually not conducive to rust.

I am trying to look on the sunny side of this current infestation... it forces me to get rid of some plants (I have way too many for our shady property, anyway, which is why the pots), it forces me to take a hard look at what is left (is this plant going to cause me hassle in the future?) and it has forced me to re-think my pollen dabbing schemes somewhat (hopefully to the benefit (rust resistance) of future seedlings).

Rust will not survive in dirt or soil for any length of time, rust has to have a living plant to live. Rust doesn't survive up north because the winter kills the foliage of the plant leaving nothing for the rust to live on, it doesn't hibernate in the soil. I live in the southern rust belt and reuse my potting mix every year by mixing it with the new.

So, Fred, does that mean that you just dump the soil, immediately mix it with new soil, and immediately plant? Or do you let it sit for a few days or a week or so?

By the way, I am building a new raised bed (inside a box kit) for seedlings. I have been reading your older "seedling progress" threads with interest, and am going to try a variation on your materials (for a start, we don't have pine bark here) to fill my new bed.

I have done it both ways, just depends when I need to pot daylilies. Like you in 2006 I saw rust for the first time and have never seen it that bad since, I have worse problems with spider mites than rust. I do spray for rust, and still always get a little in the fall, but not enough to get excited about.

Good luck with your raised bed, you can use any kind of potting "mix" or compost. I would not use potting soil or dirt, because both will become compacted and not drain very well.

Thanks for the tips and your best wishes, Fred.

After some consideration, I think that I am going to use a combination of a planting mix that I use in my vegetable beds (most of the native soil in my garden is acidic clay), along with small-sized redwood mulch and some vermiculite. I guess I will have to add lime to get the pH right, and will then amend with alfalfa pellets and time release fertilizer.

One question I have, is the purpose to try and eliminate rust from the garden? If so, can you be sure you've removed every single infected leaf?

sooby,
The purpose was to be able to reuse the soil, the leaves were not being considered here. She had removed the entire plant (leaves and all from pots) and was just wanting to be able to reuse the soil in the pots.

Understood, Larry, but I'm just wondering why be concerned about the soil if the leaves are still infected?

Sooby, there is no short and simple answer here.

I don't expect that I will ever be 100% rust free, as our winters simply do not get cold enough.

My purpose, as you put it, is to manage it, preferably without resorting to the use of fungicides. If one is willing to be ruthless and destroy new incoming plants that are rust buckets (provably so, in that they manifest rust in my garden), good control here can usually be achieved, due to a combination of climate (ours is not normally conducive to rust), culling (the rust buckets), and cutting and spraying with Dawn (an "organic" control) as necessary.

My first frank outbreak of rust was in 2006. Many plants were purged then. (It about killed me to destroy a large planting of 'Icy Lemon', one of my favorites at that time - but undoubtedly one of the most susceptible.) Since then, over the years I have bought new daylilies, some number of which shortly turned out to be rusty, most of which were destroyed. Those which were not destroyed were cut back and sprayed with Dawn, and I have not seen rust on them since. (If they had gotten rusty again, then they would have been purged. I have taken that approach since; badly rusty new plants are destroyed, some of those showing only light rust are given a cut-and-spray and a chance to behave. If they persist in rust, then out they go.)

So from 2006 to 2015 has been 8+ years of a relatively (rust-) clean and peaceful garden. The rust may have been lurking, but it was not visible (I did check for pustules), and that is good enough "control" for me. Right now the conditions are apparently right for rust, hence it is showing on a lot of plants (doubtless from new rusty plants bought in the interim) - hence the purge.

And while it is a hassle and a pain, it is also okay. I needed to downsize. The rust definitely made up my mind on some daylilies I was dithering over keeping or tossing . My expectation is that things will settle down again later this year - and stay stable for some time, so long as I don't bring any more rust buckets into the garden. (I do have a problem with one of my few tet poly parents being rust susceptible; it has been given a cut-and-spray. I can't quite bring myself to purge that one (yet), but as it could potentially cause me grief down the road, I will have to keep a sharp eye on it.)

I expect that the daylilies in my garden would be boring to many people here. In part, it is a matter of my personal taste in daylilies, but it is also a matter of my culling most of the susceptible daylilies. With this latest outbreak, it has finally sunk in to me to not buy daylilies where there are rust prone ancestors in the background (with the exception of a wide consensus - not hybridizer hype! - that the plant is in fact resistant), no matter how gorgeous such daylilies look, and what AHS awards (!) they may have garnered. (Don't get me started on a rant...)

Getting back to your questions... The summary answer is: I don't expect to ever be rid of rust entirely, but I can usually manage it well enough. That leaves me with what to do with the pots of dirt (from which rusty daylilies have been removed). If there are viable spores in there, then I don't want to reuse it. If any rust spores in there will shortly die, then good - I can recycle the dirt into new pots.

Polymerous,
I would be very interested in a list of your daylilies that are not listed in the database as rust resistant but that you find have not been susceptible to rust in your garden.
I am trying my best to limit my "Want list" to daylilies that are good "clumpers" and are listed as being rust resistant, I have twenty five on my list at present none of them are the expensive new ones, but that is fine with me.

Hmm... most of mine that (thus far) have been unaffected *are* listed in the ATP database as having some degree of resistance.

A few unrated plants that (thus far) have not shown any rust include:

'Osterized'
'Sears Tower'
'Winning Note'
'Hip to be Square'
'Pale Sun Rising' (this one, for a certainty, was in the garden long enough to have survived the great rust purge in 2006)

I've had all of these for many years, and so far, so good (although that could change). H2BS is planted right next to 'Polly Wolly Doodle' which got quite a bit of rust this year, but so far is holding up. 'Osterized' (planted one rose away from 'Polly Wolly Doodle') surprisingly has been rust free thus far; "surprisingly" since one of its parents, 'Green Dolphin Street', got quite a bit of rust back in 2006. We're in the midst of a few days of rain right now, so it may be that I'll have to come back and say "oops"...

Plants that are newer, planted somewhat near to plants that got rust this year, but have not yet shown signs of rust include:

'Sun Silk'
'Small World Edwin Keith Smith'

No guarantees on any of this, of course, and your climate is quite a bit more humid than ours, which I think would translate into more problems with rust. Daylilies that aren't problematic for rust here, might well be for you.

And there are always surprises. 'Wonder of it All', which I had read (on other forums) was resistant, got a visible degree of rust this year, enough so that I am considering purging it. 'White Wolf' and 'Victorian Lace', the first of which has had rust as a new plant, the second of which has a reputation for rust, thus far (this year) are clean.

One thing that I have been working on this winter is doing ancestry research on my daylilies, with regards to susceptibility or
resistance. The ATP database has been wonderful for that. It is quite interesting what turns up...

For example, every plant that I have ever owned that had 'Wild Cherry Round Up' somewhere in its ancestry (not just as a parent, but going further back), ended up getting rust - although to varying degrees. WCRU is not rated in the database (and I have never grown it myself, so I cannot say), but both of its parents are rated as being susceptible, so it would not surprise me in the least that it, also, is susceptible. Does this mean that every and all daylilies with WCRU in their background will be rust susceptible? Not necessarily, particularly if WCRU is farther back in the ancestry and/or the other parents all have resistance, but it is enough of a red flag that I would not now buy a daylily with WCRU in its ancestry, unless it was a high percentage polymerous tet (since such plants are still uncommon) or there was wide consensus that the plant was resistant.

Other plants that got rust this year, when their ancestry was researched, similarly ended up showing rust-prone parentage.

On the other hand, some (newer, for me) plants that are still rust free, have parents which are listed as being resistant. 'Small World Margarita' is one such plant; both of its parents are resistant.

Going forward, both for purchasing garden plants and also for my pollen dabbing, I am going to research any and every plant before buying it or using it. For a lot of daylilies there is no rust susceptibility information available, however... and not just for them, but also for their parents (no parents are listed, or the parentage is given as "Sdlg x Sdlg"). In such cases, I assign such plants a neutral or borderline rating (which I think is roughly a 2.5 on the ATP scale of 1.0 - 5.0), and proceed with caution (because the 2.5 rating could be a best case scenario).

So if you are considering a particular plant, hit the database and scrutinize its ancestry. If you are just looking for a resistant plant of a particular color, search the database for resistance in daylilies of that color. Another approach would be to start with a known resistant plant (in a color that you want) and forward search its children plants. While the children plants may not have rust ratings, you can sometimes make a good guess how they will behave given the resistance (or not) of the other parent(s).

I hope that is helpful to you - and I am glad to see that I am not the only one wanting to populate their garden with resistant daylilies.

If you aren't trying to eradicate rust and purging foliage as well, I wouldn't be as concerned with the soil. In good conditions, more than half the daylily rust spores in one study survived just over a month in vials in the lab, they were not re-tested after that length of time so some could have survived longer:

http://web.ncf.ca/ah748/latent...

Survival would likely be different in the field. That's the only study that I know of that looked specifically at spore longevity and specifically at daylily rust. I did find some research for another Puccinia rust that showed spore viability was around a week at the most if they were covered by a relatively thin (5 mms I think it was) layer of soil, longer if they were not covered. That suggests to me that you could use your soil to partially fill the pots and then top off with a layer of new mix if you were still concerned.

Regarding resistance ratings, there is always going to be some doubt because of different environmental conditions even within a garden plus the different races of daylily rust to which a cultivar may vary in susceptibility. A single rating of resistant is always going to be questionable.

Thank you very much for that information, sooby. ***** It is not that I am not eradicating leaves (I am, if visibly infected), nor that I don't want to eradicate rust from the garden (I would love to). But clearly a single application of fungicides is not going to do the job (if it did, I might consider it, at least with respect to carefully spraying cut back plants and fencing them off), and I am not going to subject myself, my dog, the wildlife, or the garden (which includes edibles) to constant fungicide exposure due to regular spraying. I am not convinced that spraying does anything more than merely suppress (for a time) the rust, anyway. I have received enough daylilies from nurseries who routinely and regularly spray, that subsequently and shortly thereafter broke out into frank rust, that I am convinced of that. (Again, our climate is not normally conducive to rust and I keep an eye on things, so I am satisfied that the source of the rust was from the nursery, not from my garden.) ***** As for your idea of recycling the potting soil into the bottom of new pots, I have to ask if there is any data to suggest that the rust might be able to infect plants through the root or crown tissue? ****** Many apologies for the run-on paragraph; my *ENTER* key seems to have just broken. (....off to get a new keyboard....)

I'm glad the info was useful. There are two possibilities with delayed rust, the first as you mention is that a fungicide application has worn off, and the second is that this rust can have a lengthy latent period between infection and actually showing visible rust. If conditions are unsuitable for it, the latent period can extend several weeks.

There's no evidence that daylily rust can infect through root or crown tissue. It typically enters through the stomata in the leaves (and can infect scapes also). Where you'd have to be careful is with the handling, for example if you did have viable spores in the soil mix and touched that and then a leaf you could transfer rust that way. It's not especially likely though.

I recently had to get a new keyboard too, the space bar on my laptop quit working on one side. I'm kind of trying to adapt to typing with my right hand at a different angle so that I can hit the bar in the middle (touch typist) but for anything of length I now have to use a separate keyboard. Frustrating, as I carefully picked this particular laptop because it is so nice to type on.

Thanks for the follow-up, sooby, re the roots and crown.

The *ENTER* key is working again... for now... (DH - mostly retired but still working - is a computer graphics expert. We always have backup keyboards around the house, but I prefer the style that I am using. HIS keyboard is black and has red lights all over it... it looks like the Keyboard from He**... )

The "great rust purge of 2006" sounds like a movie title, lol. Good luck with the eradication efforts Polymerous. Sounds like a great deal of thought and effort is being employed in your approach. Keep us posted.
BTW are you anywhere near Pat Stamile out there on the west coast? Just wondering.
Bob

I believe that the Stamiles are south of here, somewhere on/near the Central California Coast. If I am not mis-remembering something that I read, I think that they are somewhere near San Luis Obispo, which is about a 3 hour drive south of here. (Bill Maryott is about an hour's drive south of my home, much closer.)