Preparing plants for winter ensures they survive the cold weather and freezing temperatures with as little damage as possible. Only perennial plants require winter preparation, as annual vegetables and flowers are replaced in the garden each spring. Not only are cold temperatures a hazard for plants, but dry air and soil upheaval caused by these temperatures can lead to damage of the leaves or roots if the plants are not properly prepared before winter descends upon your region.
Water the plants adequately throughout the fall months so they do not enter winter under drought stress. Water once weekly, supplying 1 inch of water to the bed, which will moisten the soil to about a 6-inch depth, when felt by sticking your finger into the soil. Weekly deep watering encourages the plants to form deep roots, which makes them better able to handle winter temperatures.
Weed the bed completely just before or right after the first fall frost and rake up any leaves laying around the plants. Pull up all weeds by the roots and dispose of them. Remove the weeds and leaves to prevent pests from using this plant material as a winter home.
Cut off the dead stems of most perennial flowers and plants. Prune them off at ground level or 1 to 2 inches above the soil. Prune any shrubs or trees that require fall pruning as well, as old branches are more prone to breakage and disease in the winter. Dispose of or compost all the removed plant matter.
Cover beds with a 2- to 4-inch layer of straw mulch once the ground begins to freeze. Mulch preserves moisture as well as prevents temperature fluctuations in the soil. Maintaining even soil temperature and moisture prevents frost heave and damage to root systems.