Plant Nannies have been designed to be versatile and to work in different situations. To get the best Plant Nanny for a specific plant consider the size of the plant:
With small pots use a Plant Nanny and a reservoir that are also smaller. Since recycled plastic bottles come in a wide variety of sizes it isn’t difficult to find one that suits a smaller plant.

Excellent Plant Nannies for small potted plants are the Recycle a plastic bottle RPB series, the Adjustable APB series, or the 3½” fluted watering globes that that hold a surprising 12 oz. of water.

With 9-12” pots you can use the full Plant Nanny range. Choose a reservoir that will harmonize visually with the plant.

With larger pots consider using larger reservoirs when you want longer watering duration. In plastic bottles you can use ones up to 2 liters. With wine bottles you can use both the 750 ml and 1500 ml wine bottles. Use wine bottles with a standard shoulder that is not sloped.