Yucca seeds don't require any pre-treatment such as scarification or soaking. They just need to sit on top of a moist soil with warm temps. They germinate erratically though, so I could not tell you how soon to expect something.

I've had good luck with the two species I've tried, Yucca elata, the tall soaptree yucca; and Yucca whipplei, a California species with a huge thick flowering stalk.

As far as speed of growth, with direct seeding in the ground you can expect a nice rounded plant with leaves about 18 inches tall after 2 or 3 years. It must take many many years to form a nice trunk on a soaptree yucca. In pots in a greenhouse with fertilizer, etc... you can probably get better growth than this I imagine.

Hey thanks alot yeah so the one i sowed 1/4" deep it is germanationg good something is comming out. of the seed i was so curious and kinda moved the soil and saw that something was sticking out of the seed. so yeah they are getting ready to sprout out soon i hope. hahaha Im so inpatient when it comes to planting from seeds. Yeah and the other 4 arnt budgging so i guess ill have to wait on those. but thanks for the infromation. Cant wait for them to grow up to be 18 inches tall.

They like to sprout in warmth.