I always thought those who lined their garden beds with straw were simply using it as a pathway material - a way to keep from sinking in rain-induced mud or thaw. Little did I know that smart gardeners use straw as a winter insulator for bulbs, vegetables and perennials. Affordable, attractive, and effective. What's not to like?
Above: Strawberry plants mulched with a blanket of straw emerge. Photograph via Hazel Dene.
Straw is coarse and good at trapping air, making it an effective soil insulator in the both the winter and summer months. The insulation layer it provides between the air and the ground protects the soil from temperature fluctuations, and the plants or bulbs from extreme cold or heat.
Above: Straw is favored by vegetable gardeners, especially for protecting late fall crops from cold, and the feet of tomatoes from extreme summer heat. Photograph via Bonnie Plants.
Above: Straw performs like other organic mulch, holding in moisture, preventing evaporation, and minimizing weed growth. As the temperatures warm, you can gently remove it, turn it into the soil or let it break down naturally. Photograph via Old World Garden Farms.
Above: A tip for us non-farmers: there is a difference between straw and hay, and it is an important distinction if using for mulch. Hay has seeds in attached heads. Straw is essentially "decapitated" hay (the stalks only), making it seed free. If you use hay, you will end up with more than you bargained for (weeds and grain sprouts). Photograph via DIY Network.
Above: Many nurseries and garden centers carry straw in bags or bales. Be careful when purchasing, however, as straw sold as lawn seed mulch often contains bonding agents that you wouldn't want in your garden. Photograph by Robert Taylor.