I've got a few glasses I don't use and a few broken terracotta pots. My aim is to use the glasses to create large(ish) voids in the base and then put broken terracotta pot pieces on top. I'm using a stainless steel sieve to make the wick.

I'm using several layers of burlap to cover the glasses/terracotta/wick to prevent soil from getting in there.

I drilled two weep holes just below the burlap level to allow drainage to prevent the water from filling too high. With the soil in the container the reservoir at the base held a bit over 1 gallon before water started coming out of the overflow holes.

Before I put together a few more of these I wanted to ask:

Is the reservoir large enough? A gallon seems like a fair bit of water. I'm planning on growing tomatoes and peppers.

Can I expect any problems with this setup? Is burlap OK? I understand it decomposes with time so have it layered pretty thick - I plan to find a more durable barrier for next year (or the one after, depending on how long the burlap lasts).

Thanks in advance for any help or advice.

Photo 1 - Glasses + Wick:
Shot at 2012-03-11

Photo 2 - Terracotta pieces to help fill out the base area:
Shot at 2012-03-11

Photo 3 - Burlap over base:
Shot at 2012-03-11