Wooden planter boxes add a touch of natural beauty to any urban balcony, rooftop, or patio. However, constant exposure to soil and water can cause the wood to rot, significantly shortening the lifespan of your beautiful garden feature. The key to preventing this and ensuring your plants thrive is using the right liner. So, what is the best liner to use inside wooden urban planter boxes?
The best liner balances protection for the wood with the health needs of your plants. Here are the top choices:
1. Plastic Sheeting or Pond Liner: This is a highly effective and waterproof option. Using a thick, durable plastic sheet or a dedicated pond liner creates a complete barrier against moisture.
* Pros: Excellent at preventing rot, very long-lasting.
* Cons: You must drill several drainage holes in the *bottom* of the plastic liner to prevent waterlogged soil, which can kill plant roots. Avoid lining the sides completely, as some air flow is healthy.
2. Landscape Fabric: This is a popular, breathable alternative. Landscape fabric allows water to drain through while keeping the soil contained.
* Pros: Promotes good drainage and aeration, prevents soil from washing out.
* Cons: It is not fully waterproof, so over many years, some moisture may still reach the wood, though the fabric significantly slows the process.
3. Combination Approach (Highly Recommended): For the ultimate protection, combine the methods above. Line the entire interior with a plastic sheet (with holes punched in the bottom for drainage) and then add a layer of landscape fabric on top of the plastic. This creates a powerful moisture barrier while the fabric helps separate the soil from the plastic, improving the overall garden environment.
What to Avoid:
Avoid using non-porous materials like solid rubber or sealed vinyl on all sides without drainage, as this will create a swampy environment. Also, avoid using treated wood liners that could leach harmful chemicals into your soil, especially if you are growing edible plants.
The Essential Step: Drainage
No matter which liner you choose, drainage is non-negotiable. Ensure there are adequate holes in the bottom of your wooden planter box itself. When installing your liner, make sure these holes remain clear and unobstructed. Adding a 1-2 inch layer of gravel or pebbles at the bottom of the lined planter can further improve drainage.
By selecting the right liner and ensuring proper drainage, you can protect your wooden planter box from rot and create a healthy foundation for your urban garden to flourish for years to come.