How do i finish my sons art project?

i have made him a flower using real petals which were fresh but i need to 'dry' them out so when he takes it into school it stays in one piece. i was going to use clear varnish but the petals are delicate and am worried will make the whole thing fall apart. anyone any tips on something that is simple to do.i tried glue and water as sure seen this done but hasn't worked just made it soggy. oh yeah and it has to be in tomorrow!i have searched every site online...any help would be appriciated...thanks