Cool Is Linseed Oil Safe For Raised Garden Beds References. Web linseed oil is the oil extracted from flaxseed. As we are well aware, water is the main reason why wood rots and decomposes very fast.

The oil completely covers and soaks deep into the wood preventing water from seeping through. Linseed oil may also be available at local woodworking or craft stores. Linseed oil is a byproduct of flax seeds, and it’s a common outdoor wood preservative.