You spent hours plotting your vegetable garden out on paper, checked the calendar for recommended planting dates, purchased saplings and ordered the very best seeds you could afford. Then came the hours of bending and kneeling and carefully planting the promised delectables when suddenly, you hear the weather forecast It seems that no one bothered to share these planting plans with Mother Nature, and she has plans of her own.
What do you do when the weather forecast predicts an unexpected freeze? It really isn't feasible to dig up all your plants -- not when roots have already started to grab on. Relax; there are things to do to protect those young saplings that will keep your plants healthy and strong. Surround your plantings with mulch or an organic like straw that will help to keep the soil warmer and keep it moist. In windy areas, cover the straw with bark or wood chips; you could also use black-and-white newspaper covered by a layer of wood mulch. When you water, use a gentle trickle or light spray over an extended period of time to help the roots grown downward and make the plant stronger.
Another precaution you can take in advance is to stake a wind tunnel frame over your plants by setting a row of curved PVC pipe over saplings; when the cold weather hits, pull a light blanket or burlap over the tunnel and hold it in place with stones around the edges. You can also use a heavy layer of vinyl, which will also keep the heavy rains from flattening the early growth. Covering the plants and blocking the sun's rays for up to three days is usually not harmful, the covering can be pulled back during a sunny afternoon and covered again at night. Another option is to cut the bottoms off of transparent plastic soda bottles, remove the caps (save them) and place a bottle over each sapling. The bottles can be capped for protection on cold nights.
Farmers have long used a variety of "cloches" to protect their crops. Cloches are, quite simply, plant covers, some of which can emulate greenhouse conditions. Clear glass bells are used over newly sprouted seedlings because they hold the sun's heat in and protect the new growth from the elements. It is important to also allow air to circulate or you could suffocate the plants, so raise the glass off the soil with a ring of stones or sticks. Soda bottles and glass jars are alternative cloches. Pre-manufactured cloth cloches can be purchased en-masse and simply placed on plants, although many home gardeners prefer to poke a hole or two on the sides to allow for air circulation. A plastic grocery produce bag over a stake (taller than the plant height) and held down with stones can make do temporarily.
If you are really caught short by a freeze and don't have to contend with heavy winds, surround your garden with lawn furniture and suspend a blanket using rocks, clothespins or nails to hold it in place. To protect your plants from high winds, surround the garden with stakes and attach vinyl, burlap or heavy mesh to each stake. If you are cultivating young fruit trees, wrap the trunks with burlap to protect them from the cold. And if you receive an extended freeze forecast, make sure to pick all of your nearly mature produce to finish ripening on the kitchen counter.
Deck gardens are also subject to Mother Nature's whims. Bring small hanging plants indoors when there is an unexpected freeze. Wrap bubble-wrap or blankets around the containers of larger plants to insulate the soil and use cloches over the plants if you can't shelter them indoors. Move your outdoor deck plants close to the building and fashion a secured wind screen (heavy mesh, burlap or a blanket) on a lean-to from the building to protect them from frosty winds. The heat from the structure will help to keep the plants warm.