Yes, using a liner inside your urban planter boxes is a highly recommended practice to protect them and ensure plant health. Liners create a crucial barrier between the moist soil and the planter's interior walls. This simple layer prevents water damage, inhibits rot in wooden planters, and stops mineral stains or corrosion in metal or concrete ones. It also helps retain soil and can make seasonal cleaning much easier.
When selecting a liner, material choice is key. Flexible plastic pond liners or heavy-duty polyethylene sheets are durable and affordable options. For a more natural look, consider coconut coir or burlap, though they break down over time. Avoid non-porous materials without drainage modifications.
Crucially, a liner must not compromise drainage. Always puncture or cut several holes in the bottom of the liner, aligning them with the drainage holes in your planter box itself. For best results, add a layer of drainage material like gravel or clay pebbles at the bottom before placing the liner. This system allows excess water to escape freely, preventing root rot.
Proper installation involves fitting the liner snugly against the planter's walls and bottom, trimming any excess material above the soil line. This protective step significantly extends the lifespan of your planter investment, keeps your plants healthier by managing moisture, and maintains the aesthetic appeal of your urban garden space for years to come.