Absolutely, using a liner in your urban planter boxes is a highly recommended practice. It serves several crucial functions: protecting the planter material from moisture damage and soil stains, improving drainage management, and preventing soil from washing out through drainage holes. The liner acts as a protective barrier, extending the life of your planter, whether it's made of wood, metal, or a decorative material.
When selecting the best liner material, consider these options:
1. Landscape Fabric or Geotextile: This is often the top choice. It's permeable, allowing water to drain while holding soil in place. It prevents root rot by facilitating good drainage and air circulation.
2. Plastic (Polyethylene) Sheeting: A durable and inexpensive option. Ensure you puncture ample drainage holes at the bottom to prevent waterlogging. A thicker mil plastic is more durable.
3. Cocoa Liners or Burlap: These natural fiber liners are biodegradable and offer a rustic look. They provide good aeration but will break down over time and need replacement.
4. Pre-formed Plastic Liners: Rigid inserts designed to fit specific planter shapes. They offer excellent protection and easy cleanup.
Best Practices for Installation:
Always ensure your liner has adequate drainage. If using a non-permeable material like plastic, cut or punch several holes in the bottom before adding a layer of gravel or pebbles. Then, add your potting mix. The liner should not seal the top; allow the soil to breathe from the surface. For wooden planters, a liner is essential to prevent rot from constant soil contact.
In summary, a liner is a simple addition that greatly enhances the functionality and longevity of your urban planter. For most gardeners, a layer of landscape fabric provides the ideal balance of drainage, root health, and planter protection.