There are some cons when using terracotta self-watering spikes for container gardening or garden irrigation. These cons are similar to clay pot ollas. Here is a list of a few of them:
- Terracotta clay spikes are brittle and can be easily broken. Especially when dropped.
- Pushing the clay spikes into the dry hard ground can cause them to break. Dig a hole and bury them instead.
- Wine bottles or 2-liter bottles full of water are quite heavy and can cause clay spikes to break.
- Hard water, additives, and fertilizers can clog the pores affecting performance.
- If used outside, plastic bottles can be blown away in the wind. Wine bottles can rattle in the wind causing cracking and breakage.
- Clear plastic or glass bottles can develop moss inside and can be unsightly. (See: Example of Algae Inside Clear Bottles – Terracotta Watering Spikes)
- Soil type is important. Terracotta watering spikes perform best in loose potting soil that can wick the water away from the spike. Dense clay soils do not work as well.
- Clay watering spikes cannot be left in the ground during cold winter months. They will break when the ground freezes.