I grow hard shell gourds every year, usally bird house gourds- this year will grow alot other types. The thing to do if you want to save
seeds, is to not let the gourd freeze! The germination rates go down greatly if they freeze. As for drying gourds dont leave them in a bag, they need air to dry! I lay them on my garage floor (unheated garage) and the skin will start to rot and get real moldy- there is nothing wrong with the gourd if it does that it is 100% normal! The skins rot leaving the woody shell underneath.It takes a good amount of time for the skins to rot, and the shells to fully harden- usally I clean them in
spring or Early summer in the year after Ive grown them. Proper air circulation is the key. You can set them on old wood pallets so the bottoms get air on them.Dont drill small holes in it to try to make it dry faster! Save cutting any holes or opening them up if you intend to use the gourd until its fully dried! If the sides or bottoms start sinking in, the gourd more than likely has too thin a shell to work with. It will sink in no matter what you do with it in time. Usally end up with a few that are unusable. A thick walled one will dry right. A secret to thicker shells, is to up your potash during the
growing season partuclarly when the gourds reach a large size.
Sometimes the molds that form, will make neat birdeyes (almost like birdeyes maple finish) effect on the shells when you clean the skin off. For cleaning the skins, I use a bucket or a wash tub,full of water and a copper scrubber pad- the kind (you use to clean pots and pans). Soak the gourd in water and get the skin nice and wet (water will soften the skin), and use the scrubber to clean off the skin, it goes very fast with the scrubber. You may want to wear gloves when doing this, as some people are sensitve to the molds that form on the rotted skins.Rinse off the gourds after its all clean, and set it in the sun to dry off (usally takes 15 minutes or so) The result is a nice clean gourd, ready to work with when it drys off!
Here is a link on how to save hardshell gourd
seeds from Turtlefeathers.com. They sell hardshell gourd
seeds, many odd types too.
Saving Gourd Seeds