In the past I have recommended pyrethrum but not any longer. It is too toxic - it also has a good chance of being laced wiyh DDT which is the pesticide used in Kenya where much of the pyrethrum is grown. Sure, pyrethrum is a natural material - so is hemlock arsenic and many other toxic things.
Pyrethrum is toxic to all vertebrates - birds, lizards, frogs, toads, cats, dogs, you and me. Essential oil products are toxic only to invertebrates like insects and slugs, so of course that's what we recommend. Pyrethrum and the synthetic pyrethroids also are especially bad for people with allergies and can cause allergy problems including asthma for children and adults. Bottom line -there are no pyrethrum, pyrethrin or pyrethroid products that are acceptable in an organic program.http://www.dirtdoctor.com/organic/garde
Avoid all products:
Trade Name Common Name
FuryÂ® / MustangÂ® Zeta-cypermethrin
PounceÂ® / AmbushÂ® Permethrin
WarriorÂ® / KarateÂ® Lambda Cyhalothrin