They can tolerate alkaline soil better but no idea about cold hardness. Usually, you see them growing right into limestone bedrock along the rivers and springs around central Texas. No knees but they grow lava-like roots over the bedrock.

Good thing about central Texas BCs is that they are less likely to grow knees compared to others going in the east.

They have good drought tolerance but the needles do turn brown if they go too long without water to preserve water inside. They come back whenever it starts getting water regularly.

Mine are definitely cold-hardy to upper Z8! Will be very interested to know how cold tolerant they prove to be. Please repost on this subject when you've tried them. We're are not sure of their exact pH limit, but as mentioned, they grow on top of limestone rock shelves with caliche clay soil and black top soil with bits of limestone in it. Definitely will thrive in 7.5 pH and I suspect 8.0 pH will be ok also. Their color has a tad more blue-green than std. bald cypress.

I googled to see if anyone was selling FR BC and found this site where it was auctioning it and it happened to be in Kansas.

From the site -

DESCRIPTION

Prairie Wind Aquatics

1413 W. Mary Street

Garden City, Kansas 67846

620-276-0700

Bald Cypress âÂÂFrio RiverâÂÂ��"50âÂÂH x 25â W��"Pyramidal shape, drought tolerant, grows in various soils, this variety tolerates our high PH soils, classed as a shade tree.

Here is a link that might be useful: FR BC

I think the source for BC was Frio River and it says zone 5 from that nursery in New Mexico. Probably would have to email to find out for sure. I just recall someone telling me that it was from Frio River.

Here is a link that might be useful: BC from New Mexico

Bald Cypress don't do well in zone 5, maybe if you were border 6 you have a shot.