Utilizing the thermal mass of cob is a very old method of creating microclimates in your garden. The cob holds onto the heat from the day, keeping plants a little warmer at night. The cob walls can also act as a wind barrier and give the plants a little added protection from the elements. We have also found that sometimes squirrels think you have built them a super nice home, so do be mindful that the protection from the elements may attract certain predation.