Meet our Breeders We have been breeding Koi in Toddville Iowa since 1999, thats years. Toddville is about 5-10 degrees colder than say Iowa City Iowa. We breed from Japanese Stock that we purchased in 2004. Weather fluctuates quite a bit in Iowa in the spring which makes it challenging to breed koi in Iowa. Some years we may be able to spawn the koi in April, other years not until May or June. The Iowa Koi growing season is very short, with koi harvest typically in September. The Japanese do not leave their koi outside during the winter and neither do we. Would you leave these precious babies outside? I dont!