I don't know, but that's a good question. After I ordered from santarosagardens.com, I happened to think about fire ants (nursery is in FL) and it worried me a little. :( I wondered how they might be treated before putting in the garden.

Fire ants scare the fire out of me...

Seems like hostas had a problem a little while back with foliar nematodes or something like that. Annual geraniums (pelargoniums) had a problem with raulstonia, but it should be noticeable before the plant enters the retail industry. And fire ants are working their way into Tennessee pretty quickly. They're all over West TN. Fire ants scare me too though! Daylily rust is a serious problem - especially if you grow your plants in a greenhouse, it's nearly impossible to treat!

Introducing plants into new areas have caused quite a stir - these are the reasons for no American elms and American chestnuts!

The good news on daylily rust in this area and north of us is that the winters kill it. It is difficult to control it coming into your garden too. Your neighbor down the road might buy a rust infected daylily from Walmart or Lowes (I have seen it in both places) and it infect your garden. If your daylilies are grown well and are healthy when they get rust, they will get through the disease and be fine the following spring. We have gotten rust twice and have never lost a plant. Lots of great research out there on this subject.

Rebecca

Yeah...the fire ants are marching northward. Closely followed by the armadillos.

Or as we like to call them...Armor Plated Possums.

I saw fire ants this past summer in a garden in Maryville.

I've had a slow day at work and decided my company needed more expertise in the field of daylily rust. So, as a conscientious employee, I have been studying that subject today.

All the recent material I can find, including a lot of recent AHS material, seems to indicate that rust can overwinter in many places in zone 7 and is almost universally hardy in zones 8 and warmer. Also, evergreen and semi-evergreen varieties are likely to keep the rust going through winter. Since Knoxville is now zone 8 and surrounding areas are probably at least 7b, I'm not convinced that an average winter (now that we've warmed up) is going to reliably eliminate the rust.

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I think the disease I was worried about on the roses was rose rosette disease. Looks like I'm going to need another slow day at work to research it. I just re-found Ann's site about RRD, so I guess I'm off to do more reading.

Here is a link that might be useful: Ann's RRD Web Book

My site is about Rose Rosette Disease which is all over east and central TN.

There are some other real nasties out there:
Chili Thrips are a major scourge in south Florida that are spreading along the Gulf Coast and points northward. And there are many, many potential host plants. I really want some Meyer Lemon trees, but until I am sure that a sterilization program exists for soil and plants, I'll be lemonless.
The also nasty oak diseases from the western US can come in on plants as well. I know someone in SC who got it into his soil two decades ago when it was less known.

I don't worry about 'us' all that much. Everybody here is pretty much on the ball and will notice something is wrong and do something about it.
I DO worry about neighbors who might bring a plant back from Miami and thing that its distorted leaves are supposed to be that way.

Ann wrote, "I don't worry about 'us' all that much. Everybody here is pretty much on the ball and will notice something is wrong and do something about it."

Ann, are we talking about the same 'us'? LOL

I see lots of swapping going on here on Gardenweb. If plants are bought by the average non-plant person at the big box store, chances are at least fair that the ag inspector has checked the stuff out. When Gardenwebbers trade stuff, who knows what's hiding in the dirt or plant material. And, while there are some very knowledgeable people on this site, there are many many many more that are plant nuts without anywhere near the needed knowledge of pest and disease issues. I'm constantly amazed at the number of people on Gardenweb importing rank 1 invasives into their garden. I'm pretty knowledgeable about a lot of plant stuff, but I'm sure there are LOTS of nasty stuff out there that I wouldn't have a clue about how to handle. Daylily rust is a perfect example. Until I started studying it a little in the last few days, I didn't know much about it at all. If I thoroughly investigated every plant of mine that was less than in perfect health, I'd never get anything else done at all. I try to keep on top of important pest and disease issues, but I sure don't trust myself and am constantly concerned about those that I trade with.

When I say "us" I tend to think of we who talk as well as trade.
The trades do worry me; I also worry, big time, about the plants that are sold on E-bay. I really expect RRD to go cross country into the garden of someone clueless who is so pleased to have gotten a cheap plant that the ultimate cost will be inconceivable to that gardener.

Have you seen the daylily rust pages linked below?
The plant inspectors have an organization called APHIS and they have some info on potential pests and what cures are currently available. (Mayo used to have the Fertilome systemic fungicide mentioned) Right now, I"m just lucky that the rust specfic to roses hasn't made it into TN yet, although I've seen it on a major garden in SE PA.

This sort of thing takes a lot of the pleasure out of gardening.

Here is a link that might be useful: Identification and Control of Daylily Rust-Auburn