What Is a Drainage Plate in a Planter?

Saucers and Dishes

• Some pots and planters are sold with saucers or dishes but most drainage plates are sold separately. They come in various sizes to fit the bottoms of pots with small to large diameters and are made from ceramic, terra cotta or plastic. Most styles have raised sides to hold between 1 and 2 inches of water. You can also use an old dinnerware saucer or small disposable aluminum pie tins as drainage plates. Avoid pots with attached drainage plates, as they cannot be efficiently emptied when overflowing and promote root rot.

Double Pots

• Double potting is the practice of placing one or more smaller pots inside a larger container. This enables you to display plants in decorative containers or long planter boxes that have no holes in them for drainage. You can line the larger vessel with sheets of plastic instead of drainage plates to protect it from the draining water. Adding a layer of gravel to slightly elevate the pot bottoms above the water inhibits root rot. It’s a good idea to occasionally remove the smaller pots and pour out accumulated water to prevent musty odors. Double pots are good for displaying seasonal plants and flowers and combining different varieties in one container that have diverse water and fertilizing requirements. Plants that tend to invade neighboring plants when planted in gardens are easier to control with double potting.

Self-watering Planters

• Self-watering planters have drainage plates with features that automatically draw water from the plate or saucer up into the plant. The bottoms of the planters or pots absorb the water through small soil columns or tiny pieces of rope that slowly soak up water as the soil needs it. More sophisticated models have moisture sensors that activate the absorption process. Self-watering planters are practical for plants left on their own at weekend cabins and for people who are unable to regularly check their plants for water requirements.

Drainage Tips and Hints

• If you have a pot with no drainage holes, the best way to produce them is with a drill fitted with a small bit. To prevent soil from leaking through over-large drainage holes, line the pot with a coffee filter or cheesecloth. Despite prevailing practice, lining pot bottoms with gravel or small pebbles does not improve drainage but instead prevents plant roots from receiving the air they need to thrive.