For use indoors or out, these hollow terra cotta spikes are ideal for plants that need a consistent water supply. Simply fill a bottle with water, set the terra cotta spike in the soil next to your plant and insert the bottle into the spike. Water seeps steadily through the semi-porous ceramic, slowly wicking into the soil below the surface. At a glance, a low water level in the bottle tells you it's time for a refill.
A small and a large version are available. The 5 1/2" long small spike includes a screw-on adapter that fits plastic pop bottles, and with a 2 litre bottle can last up to 2 weeks without refilling. The 6 3/4" long large spike can hold a wine bottle or any other long-necked glass bottle with a neck diameter up to 1 1/4"; it weeps faster than the small spike (emptying a 750ml bottle in a few days), useful for larger containers and plants that require more water.
An efficient, convenient watering system, also excellent for keeping transplants healthy until their roots are established.