You must have FIREPLACE and BLACK BLOCK to make CANNON. You can find this item in misc blocks category. It takes 1d11h08m20s to grow CANNON from seed to tree. Breaking CANNON gives you 11 experinece points per tree and block you brake. There is no data about durability. There is no data about seedratio. Oops, there is no entry in the database about gemratio. If you know something, please share. Unfortunaltely blockratio information is not available.