signet said:So here is my dilemma , I have bought daylilies from a grower in Ontario , however that grower gets them from Florida ( possible rust on southern plants.) How do I know I am not getting infected plants when I buy those ?
If they are shipped from Florida in the same year you buy them then you don't know unless you can see rust on the plants already. A plant that has internal rust may not show it on the outside until some time later. If the seller overwintered the plants in Ontario, and not in a greenhouse or otherwise protected from dying back completely, then they should be safe.
Should I only buy from Northern growers to avoid rust .
That depends on the above answer, do you know they aren't bringing in plants from rust endemic areas the same year they sell to you. But in the unlikely event you do get rust, it's not likely to survive until the next year. Daylily rust has been in North America since at least the year 2000. Many people in Ontario have brought it in on new plants since that time and it has not survived the winters here.
Which is worse rust on a southern plant or gall midge on a northern plant.
Gall midge on any plant wherever it is from!
If I grow a southern plant ......that has rust , and it somehow infects my other plants , now I have a real problem right?. You say it cannot survive the temps where I am . Are the powers that be 100 % certain this is the case?
If your daylily leaves die completely back in winter rust cannot survive unless you also grow Patrinia. If it was going to survive in your area it surely would have by now since so many people bring in plants from the USA and have been doing for the seventeen plus years the fungus has been in North America.
As for gall midge how likely is it to come to my garden if I ordered plants from Northern Ontario , Or Nova Scotia ( which I have in the past for many years) Or BC which I also have done but not as often.
Impossible to say. It is more widespread in BC than it is in northern Ontario and Nova Scotia, where it is currently only in a handful of gardens as far as we know. But it can fly so it will eventually spread unless there is not a continuum of daylilies to act as a conduit (e.g. the "ditch lily"). It could actually be in other places in North America, since not everyone is going to report having it.
This gall midge thing is only one more and the latest thing to dispell the " easiest carefree perennial to grow " myth attached to daylilies.
The gall midge is much more of a concern in cold winter climates than daylily rust. Daylily growers far south of you in the USA don't have rust overwinter. Since the midge is in northern Ontario and Nova Scotia we know it can tolerate cold winters.
Popularity is a potential problem with any plant (if you grew 3,000 of some other plant, and many other people did also and shipped them around to each other as much as we do daylilies, there would be problems). We not only share the plants but any problems they may have in that garden. Then we grow a monoculture of that plant making it easy for any pest to proliferate. The ease of growing daylilies, and of shipping them, are part of the problem.
If some persons hadn't imported daylily rust, the daylily leafminer, and the gall midge from overseas without their getting intercepted by the plant protection authorities, we wouldn't have these three relatively new problems. All three arrived since the year 2000.