When is breeding season?

When is it? And how big does my male and female have to be to breed.Also what is proven out a breeder?

Traditionally bp breeding season is the fall and winter, however, in recent years more and more breeders are pairing adult snakes year round with good results.

A general rule of thumb, especially for a new breeder, is the female should be a minimum of 1,500 grams (that being 500 grams per linear foot) and in her 3rd year of life. The male should be a minimum of 700 or 800 grams. Those are just general guidelines though. Many experienced breeders breed at different weights and ages but do so because they know their animals and the stress of breeding/egg production very well. All guidelines aside, it's also important to judge each snake individually as to their fitness to breed. That is something that you just develop with experience, you just "know" if they are good to go and sometimes you pass an animal by because they just don't feel "right" to you.

A proven breeder is one that has reproduced successfully. For a female that would be laying eggs, for a male that would be siring those eggs.

Great answer Joanna!!
I have a female BP that is around 4.5ft long, but only 900g. She keeps getting longer and longer without putting on much weight. Someone who didnt know might think that she is ready to breed due to how long she is. The most important part for a female (this is where the 1500g mark is important) is body fat; without enough body fat the female is unable to live for months without eating as well as produce a clutch of viable, healthy eggs.

I am going to be using the year round method going forward; IMO captivity lets us breed BPs whenever we can stimulate them to. This is benificial because we can breed according to the snake's weight and conditioning, rather than rushing an undersized/developed animal that only needs a few more months to be ready.
I've also been toying with the idea of a breeding room, with 'winter' photoperiod and cooler temps that I would move the breeders into. The one thing I havent really worked out yet is the best way to acclimatize them to the change. Not risking RIs or anything... sooo not worth it.

Based on all the LATE hatch 08's I see at the show, some folks are already breeding year round, pretty much.