There are different methods for rearing snails. Usually in France, reproduction and nursery take places indoor, in climatized areas, and fattening outdoor, in pens. It's more efficacious and hygienic. But we can also simply use a greenhouse.
Snails are hermaphrodites but they have to mate before laying some days later.
When a snail has laid, the pot is placed into an incubator at 20 C and covered. Three weeks later, about 100 new hatched snails appear under the lid. Usually, we can expect a yield of 70 young snails per breeder for 2 months. 3 to 4 weeks later, these young snails are brought outdoor. We have to protect them against rodents and shrews, for example with a grid in the ground.