Zelkova Species, Japanese Grey-Bark Elm, Japanese Zelkova

Germination
For faster germination, soak the seeds in slightly hot water for 24-48 hours, followed by 6 weeks of cold stratificati...Read Moreon before sowing in sterile gardening soil. Keep damp soil, not soaking wet. Keep pot in warm situation, 68-75 °F. Germination usually occurs in one to two months. It can be more depending on their degree of unbroken dormancy, don't give up.
Scarification / Stratification
This will break their dormancy. It creates a cold and moist environment for the seeds. Mixed in seeds with slightly moistened vermiculite or peat, only damp in a ziplock bag. Close zip bag shut and store it in the salad crisper compartment of your refrigerator. If any seeds begin to sprout during the cold stratification, simply remove the seed and plant. - See more at: http://www.rarexoticseeds.com/en/zelkova-serrata-seeds-japan...

I have read that this plant grows in zone 9 but have never seen one in Florida. I have planted several plants in zone 9a (including sever...Read Moreal cultivars) and had good growth from them for several years now. I even get a little orange fall color.