Ferns generally have a green, earthy, or slightly sweet scent. When crushed or rubbed, some ferns release more of their aromatic compounds and might have a herbaceous, mossy, or floral undertone. However, it's important to note that the specific scent of a fern can vary depending on the species and growing conditions. Some ferns may have a very subtle or mild fragrance, while others might have a more noticeable or distinct aroma.