You can use the pellets but be aware that the roots of winter sown seeds tend to grow rapidly and will escape the pellet before the plant is very large at all. I've seen reports of them growing out of the pellet before the first true leaves appear. You would need to keep a close watch on them and be prepared to repot them soon or the roots may be damaged. I find that the netting on the pellet should be removed and that is difficult if roots are growing through it. I like the ease of sowing in the pellets but found that in the end they mean more work. I prefer the peat pots that I can fill with my choice of potting mix much better. It's a little more work initially but one less transplant required, and in the long run the plants seem to do better.

Sandy