Doesn't matter to me. How about the size of the pot or the age of the plant. Is it a tc liner that has only been in a pot one year, or a field grown tc that has been growing for 3 years? ROOTS matter...whether they are in a pot or in the ground.

-Babka

I've been looking at several mail order sites and see some offer container grown plants saying there is less chance of disease while the sites offering field grown stock says theirs are hardier. Noticed most of the field grown are third year plants.

The places that I buy from often state that container grown plants have less chance of disease.

To me the pot-grown is a feel-good as far as disease is concerned. If it's there, it can still spread to others through cutting tools, watering, and any critters they might be exposed to that nibble on them. Guarantees are important, but so is meticulous disinfecting of all tools, and testing by the seller personally (regardless of how the plants are grown). Sadly most guarantees are either only good for a few months, or not much more than a year, and most sellers don't do any testing themselves. So unless you test your new plants while your return or refund or replacement guarantee is still in effect, you may not see any problems until after your warantee has expired.

If you can absolutely trust the seller of the pot-grown ones, then you may only need a replacement guarantee for a few days, until you see if the plants you receive have root rot damage, which some can have from being cramped up in a pot. For someone in your zone, field grown in as cold of a climate might be better, but again it might depend on all the details. Field grown plants are exposed to more chewing critters, and in addition to cutting tools, get the shovel treatment and washing soil off the roots (which may reuse the same water for all the plants being shipped). And if there ever was disease in any of that soil, it could stay infectious for a while.

Maybe it all goes back to whether the sellers are regularly testing their plants themselves, or if they're solely relying off of the fact that the TC labs their plants originally came from test their stock before growing it. If so, they're trusting the labs and you're trusting them, which is a lot of trust with no solid proof/evidence for you to see of any of that testing. I too have trusted someone's word, and the plants indeed looked perfect upon arrival, and for several years, originally had come from a tested place, but now it looks like infection might have occurred somewhere along the way, and it can be hard to impossible to know where/when. Maybe I'm speaking prematurely, or at least I hope I am or else my collection might be in trouble despite of trying to be "careful" (but maybe not careful enough). Planning on doing some *testing* of my own this year to find out. Caring "too much" can sure be a drag sometimes.

Forgot to state another difference I've experienced myself. While the pot-grown ones I've purchased survived when planted directly into my clay soil, they did not grow much (if at all) for a whole year. The pot-grown ones that I bought bags and bags of potting/planting soil for (and planted in the ground that way) seemed to grow/do better during the first year. But replacing large holes of hard/native soil with soft soil created other problems, so a good mixing of the two should definitely be done in the whole yard.

In other words, the pot-grown ones might have a bigger adjustment period being taken from 100% potting soil to your native soil, especially if you don't do some mixing/prepping (but if you plan to keep them in pots then that wouldn't matter). The field-grown ones are no longer used to the ease of being in fluffy "soil" and might do better if you plan on sticking them into your hard soil directly.

How much shade vs how much sun they were grown in might be another consideration, but if your question/concern was about minimizing risk of disease then this is irrelevant.

Disease, bugs, fungus can grow in greenhouse pots as well as the soil. A dedicated, knowledgeable, responsible grower will take the necessary precautions to check his incoming stock and use good cultural practices to insure the plants they sell are healthy. Best bet its to get your plants from a reliable source. You might pay a little more, but your risk is minimal.

-Babka

For me, I have noticed that pot-grown hostas quickly fill a pot with roots then start to stunt their growth, whereas the same hosta in the ground will be much bigger overall. It gets very expensive to continue repotting into bigger pots just to give the hosta more room to stretch those roots. I have the vast majority of my collection in the ground and only a few in pots, for that reason.

No instant gratification with hosta, eh? For 48 bucks, there is. Heh heh heh heh heh...

Wow, Don what a find! I would call that instant gratification, too.

bkay

I couldn't find the best list, which was done about 5 years ago. I think Steve from Mass did it. It contained lots of information from lots of buyers about lots of vendors.

This one lists the vendors that are the most popular/often used by the contributors to this forum.
[https://www.houzz.com/discussions/reliable-places-to-buy-a-hosta-2017-dsvw-vd~4474445[(https://www.houzz.com/discussions/reliable-places-to-buy-a-hosta-2017-dsvw-vd~4474445)

bkay

In my limited, anecdotal experience, I've found better growth the following year from a nice full pot transplanted into the ground than a freshly uprooted field grown Hosta transplanted into the ground. Seems like the field grown one returns from winter the same size. Probably due to more root disturbance and/or being bigger to start with. The field grown one may still be ahead of the pot grown, but I like to see the differences year to year. Doesn't really make that much difference to me. I just get whatever I can when I can!

If you think that's worth 2 cents, I've got a bridge in Brooklyn I'll sell you - cheap.