Raised Beds: Layer by Layer to Success
Raised beds offer many advantages: ergonomic working height, better drainage, faster soil warming in spring, and protection from burrowing pests. The key to long-term success is proper layering when you fill them.
The Classic 5-Layer Fill
- Layer 1 (bottom, 8 inches): Coarse branches and prunings — provides drainage and slow-release nutrients as the wood breaks down over years
- Layer 2 (6 inches): Inverted turf or wood chips — prevents fine materials from sifting down
- Layer 3 (8 inches): Leaves, straw, and coarse garden waste — food for earthworms and soil organisms
- Layer 4 (6 inches): Half-finished compost or aged manure — supplies nutrients and generates warmth as it decomposes
- Layer 5 (top, 8 inches): Quality garden soil mixed with finished compost
Pest Protection
Line the bottom with hardware cloth (1/4-inch mesh) before adding the first layer. Standard chicken wire is too coarse — voles and gophers can fit through. This simple step saves you from heartbreak when root crops disappear overnight.
Plan for Settling
A freshly filled raised bed settles 6-8 inches in the first year as the organic layers decompose. Fill it to the brim initially and top up with compost each fall. After 5-6 years the material is fully broken down and you should refill the bed.
What to Plant the First Year
The decomposing layers generate heat and abundant nutrients. Take advantage by planting heavy feeders like tomatoes, squash, and cucumbers in the first year. Follow with moderate feeders in year two and light feeders in year three — just like field crop rotation.