Mild temperatures in the spring can draw may homeowners to plant their garden early. For Kansas City gardeners, this may be a gamble, due to late spring freezes. The average frost free day is around the middle of April; however this may fluctuate on any given year. Here are some suggestions on how you may protect your plants from frost damage.
Before you purchase plants for your home, be sure that they have been hardened off. Hardening off refers to a process whereby plants have been exposed to stressful conditions, in order for them to withstand the outdoor environment. If you purchase your plants early, pay attention to local weather patterns. If a cold spell is expected, wait until it passes to plant outside. Keep newly purchased plants on your porch or close to the house for up to two weeks. This naturally hardens off plants to the environment around your home.
Plants already growing in the garden or landscape can be protected with row covers or materials, made of plastic, cloth, straw, boxes, milk jugs or something similar. One of these coverings will act as a blanket to help hold heat around your plants. Many garden centers and nurseries have similar packaged products on the market. Be sure to remove protective covers when temperatures are above freezing. Using them should protect plants from temperatures down to 28 degrees F.
Two other less practical frost preventives include irrigation and heating. Irrigation works by using sprinklers on frost sensitive plants. Water has a unique characteristic in that it gives off heat when it freezes. When the threat of a freeze occurs, irrigation sprinklers must provide at least one-tenth to one-eighth inch of water per hour. Water must be continually sprinkled on the plants until ice melts freely off of plants. It is important however, not to use this method on plants that could be damaged from the weight of ice on limbs. Heating is another frost preventive. Outdoor heaters may be used in small spaces, however high fuel costs usually prevents homeowners from using them. Both heating and irrigation are often used in commercial orchards. Applications for homeowners are not as common.