This is probably too late to help you, Dana Harmon, but I bought some seed on eBay from Portugal, and on their webpage they say this:
"It prefers its cultivation in sandy and fertile soil, however it is tolerant to occasional humidity and is not demanding as to the type of soil, as long as it is well drained."
https://www.ouriquesfarm.com/store/seeds/trees/chinese-toon-chinese-mahogany/
The site in Portugal seems to have a lot of warm-weather
trees, so even though it's now May 12, I'm going to try planting at least half of my precious seeds in a big pot and keep it watered but "well drained!" I have a big cloth pot meant for strawberries (though the pockets don't work so I just use the main body of the pot), that would be well drained I hope. I don't have any sandy soil here so ... I'll add some sand to the pot, but I do have a small
swale; I guess IF the seed comes up, I could try planting on the side of the swale. Sort of "fertile."
Anybody else got any words of wisdom regarding growing these plants?