I have conflicting sources that say the seed must be on top or the soil to germinate and others that say to sow 1" deep. If you have experience please respond. I am planting self harvested seed from mature palms that I planted from seed 20 years ago. I was experimenting with twenty plus varieties of palms at the time and I do not think the Trachycarpus fortunei were surface sown.
I am not familiar with the plant since I live in cold zone 4. However, a rule thumb for seeds is that small and tiny seeds are surface sown (needing light) since they would be too small to reach top of the soil when they germinate. It actually isn't so much that small or tiny seeds require light, it is just so that they aren't buried and unable to reach the surface.
Larger seeds, sow them 1/3 to their size in deepth. The larger the seed, the deeper they need to be sown.
How did your seedlings turn out? how long to germinate? Often, with palms, it's to heat or not that's the ?. Being that they're a native of China and their cold hardiness, I wouldn't think heat would be an issue.