Dallas is in the northern limit of zone 8, which means winter lows are likely to reach 10ºF. The plant is listed as dormant during winter, but you will need a greenhouse or enclosed porch, as it's only root hardy to zone 9. The plant has an extremely fast growth rate, and the only reason it's not listed as a noxious weed in Texas seems to be because it's not winter hardy. Seeds are available through independent sellers via Amazon.com and Ebay.