For seeds which "pop" a large paper bag is useful. Leave the top open so drying continues. Some garden stores sell large paper bags for leaf bags in the fall.

Caroline (Zone 3 Calgary)

Wait until the phlox seed turns brown then scatter them where you want them. One year I collected seed and saved until spring to plant, not 1 germinated. Those seeds left to fall off the plant and freeze and thaw during the winter all came up. There appears to be a tough husk surrounding the seed. /Abi

I collected several of my phlox seeds last week and put them on piece of paper on my dining room table ... a few days later I kept hearing snap crackle pop !! lo and behold the seed pods were exploding ! guess I should throw them back out in the garden in order for them to germinate next spring or can I wintersow them in january or february ?