I think it's very likely that provenance does matter - with the reason being epigenetic changes. (Wikipedia fast definition : It [epigenetics] refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence.) If you Google 'epigenetic plants', it turns up lots of articles, including the one in the link below. So it seems likely that plants sourced from different locations could very well have different epigentetic changes (which are inheritable) that could affect things like hardiness.

Here is a link that might be useful: one article re epigenetics and plant adaptations

That's a good question. You may be on to something there. I have two plants that are not supposed to be hardy in my area and they keep coming back. One is the Black and Blue Salvia, and another is Salvia Patens Patio Deep Blue. They are in beds on opposite sides of the house.

I wonder how much "micro climates" in ones own yard play a larger part in hardiness.

The B&B Salvia was given to me by a local friend who grew it from seed in her greenhouse. The Patio Deep Blue was purchased from a Nursery that is in a zone colder than ours and sold in their "annuals" section.

Linda

I agree with Linda that microclimates play a big role in hardiness and survival rates. We had a mystery shrub in the garden when we moved in almost 2 years ago. I just discovered that it is a pomegranate (punica granatum) which is listed as hardy to Z8. We are borderline Z7, but the pomegranate has been here for many years with occasional winters below zero. There is a seedling coming up in another part of the yard. Both are close to the adobe wall which may keep the temperatures higher than out in the open. I would never have believed pomegranate would survive here if I hadn't seen this specimen.

Cheryl

I read an article in Horticulture mag awhile back (Jan/Feb 2012) that talked about this very thing.

They said that the reason there can be several contradictory zone listings of a plant is because of WHERE it was collected from. Over time isolated populations of a particular species evolved and adapted to the changing climate. These groups are disjunct from the rest of their species, which themselves can go thru many changes to survive. So ultimately you can have radically different plants even if they are the exact same species/look the same.

I have to say, that was one of the most fascinating garden articles I have ever read.
CMK

The quick response: how important it is depends upon how wide the gap is between the climate and conditions of the seed source, and where it is being grown. Some plant species and local sources may have a wide range of seed traits; others may have a narrower range of variability. Some plants are also more adaptable than others. But information from studies about the importance of different seed sources of trees also holds true for variation between perennial sources.

The US Forest Service does, and has done, a number of studies about seeds, sources, variable traits, etc. There is more information about trees seeds I believe, but they also study and partner for seed diversity of other plants. A search will bring some of the studies up. But be forewarned, the studies carry titles such as Effects of Treatment and Seed Source on Forest Service Germination of Eastern Redcedar Seed, and they read like the research and conclusion reports they are, and are technical in nature. But a wide range of information can be gathered from them.

Very interesting.

Although I was very familiar with Waddington's epigenetics and with (paleontological) provenance (graduate school), further development and application of the concepts, in botany/horticulture, is quite new on me.

I don't deliberately grow perennials from seed and, if fact, prefer to use cultivars raised by vegetal means.

At the same time, the information above raises a number of questions. For instance, we apparently often get perennials raised in the Carolinas, in part so they'll be in bloom when they're sold here (up north, to them). Is what seed they use a relevant issue, or, seeds aside, is it the cultivars environmental adaptability/plasticity much more important?

As to location/microclimates: it's an old gardeners' adage: if you want to know where to place a plant, buy three and plant them in different places and the plant will tell you where.

The superficially fortuitous survival of some perennial plants always amazes me.

The most extreme case I've come across is one of around 15 painted daisies (Tanacetum coccineum (Robinson's series)), which survived ten years in one garden, while all of the rest died within two or three years of planting.

They were all purchased as plants from the same place. It's hard to see seed provenance (re the grower) being the simplest explanation for this odd situation.

That one super-survivor painted daisy: I kept it and it's continuing to grow happily in our own garden.

I'm sure provenance is very important in regards to exactly how the plant looks and what it's genetics are..... But I think in many cases it's not a safe bet as far as hardiness.
There are several cases I can think of where plants were collected from colder locations to find hardier strains, but there are also a lot of cases where the historic range of a plant really doesnt match the cold tolerance.
Needle palm is an example, it's found in the sub tropical southeast, but when you actually check hardiness it's one of the most cold tolerant palms, capable of zone 6 and maybe lower.
Still your best bet for a hardier strain would likely be at the coldest end of its range or highest altitude.