Direct sow trees/shrubs from seed

How can I prep some rows to direct sow a bunch of seeds for trees and shrubs?

For example, I’m trying to plant a row of sea buckthorn from seed to work as a living fence. Elsewhere I want to plant a row of alder, Goumi etc to work as support plants.

Is this feasible or do I need to grow the trees in a small nursery separately and transplant later? I can get bulk seed so it wouldn’t be too bad if there’s low germination rates, but I’m not sure how best to deal with competition from weeds.