Most will accept international money orders if left blank, check their web site. I have done this many times and even sent cash once and it all worked out.
IMO credit card is to scary.
Take a vacation to canada buy your seeds, go to a home depot or wallmart, buy 6 packs of garden seeds, empty one pack put your seeds in reseal and mail in a birthday card to you.
Happy Birthday.
Hope you can do it. If you do remember to tell no one we don't want customs searching every seed packet do we LMFAO
Peace
If you go the beer and bitches are the dope. We got tthe best shit too.