crispy

That's great...looks a lot like a contraption that Alton Brown would use.

Qathan, this is an inexpensive way to build your own La Cloche - However, keep in mind that the manufacturer of the clay (flower) pot did not have to consider the food safety of those products. The clay may contain toxins that make the manufacturing process of the clay pot more reliable or easier. In general, a clay pot is not the same thing as clay. Clay pots are clay mixed with additives that give the clay different properties when worked and fired; thus pottery is not made from raw clay but a mixture of clay and other materials. Those additives may bake / leak out at 500F ... when you consider using this you may want to investigate this, even if it's just to confirm that the homebuild Cloche is harmless.  Many clay items like bowls and vases, glazed or unglazed, have stickers or permanent markings that indicate that they are just for 'decorative purposes'. You would not find a warning like that on a flower pot.

BROTKUNST

P.S. I read that 'lead' may be an issue in some commercial clay flower pots. There are supposedly simple test kits available that could confirm that your pot would not contain lead.