Natural wool is incredibly beneficial in the garden. Wool is a natural fertilizer for plants. Wool is biodegradable, and as it breaks down it releases nitrogen, phosphorus, and potassium into the soil. So, given that we all tend to accrue little bits and bobs of wool leftovers, what better use for them than as a plastic-free alternative to seedling planters! Wool is also highly absorbent, and watering your seedling pots from the bottom (in a tray) is a perfect vehicle for wicking up water slowly.