You may have several natural materials around the house or garden that can be of use. Pine cones, wood chips, leaves, and sticks can all be used but will break down over time—a sustainable choice for seasonal planters who repot regularly.

Synthetic Materials. Synthetic materials like plastic, fiberglass, and metal are popular choices for outdoor planters. They are more durable and weather-resistant than natural materials and come in various shapes and sizes. Here are the most common types of synthetic materials used for outdoor planters.

Plastic sheeting is the best material for lining a planter with. Pond liners work well for lining the bottom of planters as they are robust and can easily be shaped into the perfect size to fit the dimensions of your planter. Pond liners are also thick enough to reduce any evaporation of water from the soil.