Place Card Holders?

I've been really into this style of place cards, and have made a template so I can print everyone's names on linen cardstock and keep it simple. The style of our wedding is very linen and vineyard and wildflower so I thought a simple name card would work. Problem is, the wedding is outside and I just realized that these might not stay on the plates! Has anyone tried this? Should I get holders or small stones to keep them in place or do you think the dip in the plates would keep them from being too exposed to any wind? Alternatively I could tuck them into the napkin.