I grew 'Munstead' lavender successfully in Chicago suburbia. The key is good/excellent winter drainage. Currently, I have the variegated lavender, but it is in a warm microclimate, but in both gardens, I had/have the lavender planted at the top of a slope. Provided you give the lavender proper drainage, the lime soil should not be a problem.

entling's right, good drainage is the key. It's critical for winter, and important in the summer. They like a fairly neutral soil so your alkaline soil may need amendment. They can tolerate some dry; in fact, they like it dry, so don't overwater. Also, don't overfertilize -- or for that matter, fertilize much at all -- they really like things lean. And one last thing that someone told me about and that made a big difference for me and lavendar survival -- be careful when you prune -- taking the flowers is fine, but if you're going to cut the foliage stems back, don't cut all the way back into bare wood, and never cut back by more than 1/3. The right variety and the right situation and you should be able to overwinter it.

Here are some links that might help (you'll have to copy and paste):

http://www.mountainvalleygrowers.com/lavendercareandtips.htm

this guy has a lot to say about lavendars:
http://www.papagenos.com/blog/template_permalink.asp?id=99

and don't forget the herb forum on Gardenweb. There have been lots of posts there about lavendar and I'm sure you'd get some great info if you posted your question there. I did a search on "lavendar" in the herb forum and came up with this:
http://search.gardenweb.com/search/nph-ind.cgi?term=lavendar&forum=herbs&forum_name=Herbs

Also, you might contact your local extension service (look under Kansas cooperative extension) and/or master gardener's program to see if they have specific information for your area.

Good luck, and happy gardening!

Hello, Alleycallie! By Post Rock country, do you mean somewhere around Beloit? Just guessing, I grew 90 Mi NW of Manhattan, and am now transplanted to KC area. I have had success with Munstead--I start my plants from seed. As others have said, one of the keys to lavender is good drainage--it will not tolerate wet feet. I have it planted in two of the worst locations in my yard. I have some planted right up against the curb, in my mailbox garden, poor soil, full of chat rock from when they put the streets in (newer development), gets salt in the winter. It's done really well. Another place, it is basically planted in a few inches soil over rock, and doing pretty well. My oldest and largest plant--three years old--did die back quite a bit after the prolonged Easter freeze, but it still alive and has recovered some this summer.

The location you mention sounds like it would work well for lavender. Another tip I have heard is not to cut it back at all in the fall, and only prune out 1/3 of the branches on established plants in late spring, just to keep the shape.