Posted: 14/09/2014 at 09:51
Yes, unless you're sending lots. Then the issue is thickness of envelope and you might need a large letter stamp.
It's 5mm thick, up to 100g and up to A5 envelope for an ordinary stamp
25mm thick, 750g and up to A4 for large letter stamp.
You can weigh on the kitchen scales but a few packets of seed is unlikely to go over weight.