When is it time to worm the puppies?

Anytime is a good time. You should try to keep your dog worm free at all times. Take in a small sample of your dog's feces into your Veterinarian to see if your dog has internal parasites & if so, what types. Then the Vet can instruct you as to what medications are the best for the type of worms the dog may have. That would be the best way. You could also pick up a dewormer that gets all different types of worms (make sure it says it gets tapeworms along with the other types such as roundworms, hookworms, whipworms, etc.). Make sure you weigh your dog first to get an accurate weight before deworming. Repeat the deworming in 10-14 days to get any juvenile worms that have grown up in that time that might have been missed. Don't forget to have your dog tested for Heartworm at your Veterinarian. You should have your dog on a once a month heartworm preventative year around. If you have your dog on a heartworm preventative, that medication normally will also destroy most internal parasites too, such as roundworms & hookworms. It is very important to have your dog tested first by your Veterinarian before starting on the once a month heartworm preventative. You should also have your dog on a once a month flea & tick preventative such as Frontline Plus or K9 Advantix II. Just apply topically to your dog's skin once a month to keep the fleas & ticks off of your dog. Remember that mosquitoes are the intermediate host for heartworms & fleas carry tapeworm eggs.