Should I add rocks to pots without drainage holes?

When I first started gardening years ago, adding a layer of rocks to a non-draining pot was conventional wisdom. The idea behind this technique was that the rocks would act as reservoir, storing excess water until the plant drew it up from the roots.

Does this actually work? It's really hard to say. I've tried it both ways and noticed that pots with a two-inch layer of rocks at the base had looser soil around bottom of the roots than pots without rocks. Aside from that, there really wasn't much difference in how well the plant fared.

While I don't add rocks to my container veggies and flowers, I still add them to pots containing succulents. These plants thrive in poor soil and low water, and adding rocks replicates the growing conditions where they do best.

What kind of rocks should be used?  I used everything from crushed lava rock to pebbles and decorative landscape rock inside my planting containers. Broken bits of terra cotta pottery will also work.