Terracotta Olla

A buried lower pot with its drainage hole plugged holds water, which seeps slowly through the porous clay wall directly into the surrounding soil — no sprinkler waste, no standing water, no fungal disease from wet foliage. One olla waters 4–6 plants for 5–7 days on a single fill.

Materials

• Terracotta pot, 8–10" diameter (outer pot) — 1
• Terracotta pot, 6–8" diameter (inner, inverted) — 1
• Terracotta saucer, 4–5" (cap) — 1
• Air-dry clay or terracotta caulk, to seal

The Build

1. Plug the drainage hole of the large pot completely watertight with clay, caulk, or a glued terracotta shard.
2. Seat the smaller pot upside-down inside the large one — it becomes the fill cup, nesting to leave a water chamber around it.
3. Run a bead of caulk or clay around the rim where the two pots meet, to keep soil from washing into the water chamber.
4. Test before burying: fill the chamber and watch for a slow, steady seep or a damp ring on the outside over 15 minutes.
5. Dig a hole and sink the olla so the inner pot's rim sits at or just above soil level, then backfill and pack gently.
6. Plant 4–6 shallow-rooted plants (lettuce, basil, chard, beans) around it and fill the inner pot from the top whenever it runs dry.

Caveats

• Water gushing out the bottom means the drainage plug failed — reseal and retest before burying.
• Soggy soil and root rot around the olla usually means it's being refilled too often, or it wasn't buried deep enough — let it dry between fills.
• In freezing climates, drain and pull ollas before frost — terracotta doesn't survive freeze-thaw cycles.

Skip Entirely

Leaving an olla in the ground over winter in a frost zone — the freeze-thaw cycle cracks terracotta reliably, and a cracked olla just becomes a drain instead of a slow-release reservoir.