Well, sort of in the soil. Jujube, Ziziphus jujuba or perhaps more accurately Z. zizyphus, is a harder seed for me to figure out. Lee Reich indicates in his book that seeds are not the preferred means of growing these fruits, as they do not come true from seed. However he suggests cutting open the fruit stone and removing the two kernels (seeds) within. Then put the kernels in cool, moist stratification, or nip off the tip and plant into warm moist media.
I checked the CRFG page, and it only reiterates the not-true-from-seed bit. This might give me pause if I didn’t already enjoy growing apples from seed. I consulted my copy of Dr Deno’s books, which don’t offer much insight into this species. Specifically it is not mentioned in the main book nor the second supplement, and the first supplement says only, “Zizyphus (Rhamnaceae). Several samples of seeds of Z. jujubà have failed to germinate, and the seeds soon rot.” More is the pity. Deno’s work is not without its fault, but where he has data on successes, it often provides an excellent starting point and insight.
JL Hudson, where I ordered the seeds, recommends a 2 day soak, or cold treatment. The catalog also mentions giving three months of cold treatment, possibly following a three month warm stratification.
A review of what other people are doing online reinforces the idea that this species will likely respond to cold, moist stratification and then sprout when it is brought back into warmer weather.
The packet contains quite a few of what appears to be fruit pits. I tried cutting one out of its seed coat, and didn’t really do much more than nick it. I tried cracking another and crushed the seed. On the bright side it looked like a healthy seed inside. I put the nicked seed onto a moist paper towel inside a ziplock back. I also started about half the remaining seeds in a similar fashion, at room temperature. I’ll start the rest in the fall, when I move this batch into the refrigerator for the winter. I don’t expect to see seedlings from this plant until next spring.