A suggestion. We use "sheer" wedding favor bags fin our field work. The fabric is quite weather resistant/proof and they have a built in drawstring that is easy to undo later. Come in colors so you can spot them easily or hide them. Recommend you remove petals as they might mold (develop botrytis- grey mold) but the bags do breath well protect the capsules/fruit from attack and capturing quite small seeds that shed before you get back to them. We used to use old nylons with rubber bands but broke to many stems that way. Using bits of string require high functioning opposable thumbs ;-) Murphy's Law of Seed Harvesting states that a green pod on Friday afternoon is an empty pod when you return home on Sunday afternoon.