Question
Do you know what I am to do with California Poppies when they have just about stopped blooming? They are very unsightly at this point, but do want to have seeds develop for next year as they did last year but would really like to get them cleaned up a bit.
Thanks for any help.  

Answer
You only need to leave a few here and there to produce enough seed for next year, and you can clean up the rest.  If you think the seeds have grown to full size but have not ripened yet (open one pod that looks full size: are the seeds white?), you can pull up (or cut) a few, put them upside down in a paper bag, tie it closed around the stems and hang it up in a shady, well-ventilated place until the seeds mature, the pods burst and release the seeds.  Now you can just cast them where you want them next year.

Judging just when the seedpods are ready to be harvested takes practice and judgement.  If you do it too soon, the seeds will not be viable.  If the seeds have just started to turn brown, you are safe.