Most vegetable plants are annuals and susceptible to frost damage and death. If the temperature dips too low in your region of Montana, floating row covers (blankets of fabric for your plants) are an excellent solution to keep your vegetable plants warm. Using mulch (a protective covering of organic matter, though some rubber and plastic mulches exist as well) on your vegetable beds can also help to retain both warmth and moisture. Mulch is also an excellent weed deterrent. Using mulch and floating row covers in conjunction with one another will help your vegetable plants grow to their full potential.
Apply a 2- to 3-inch layer of mulch over your vegetable beds. Do not apply it directly next to your plants. Leave an inch or two of space around the bases of the plants.
Water the mulch thoroughly after applying. This will keep the mulch from leaching moisture from the soil around your plants and will encourage it to retain moisture for those plants. It will also keep dry mulch from blowing away.
Place hoop supports (large wire hoops that keep row covers from crushing tender plants) at even intervals over the rows of smaller plants in your vegetable garden. Pound them into the ground with a mallet if they will not go in easily by hand.
Drag the floating row cover cloths over each row, supporting them on the hoops. If the plants are small enough that they are not touching the cloth, you can stretch them tight as you pull.
Pile soil and rocks (if you have loose rocks around your yard) on the edges of the floating row covers. These will help to hold them in place so that they do not blow away.
Uncover the plants during the daytime when the temperature is safe so they can get sun. Recover them as needed when nights are too chilly. All of Montana has a relatively short growing season for frost-sensitive vegetables. Individual frost dates vary by locality within the state. The growing season generally ranges from late May/early June to late September/early October. Consult the Montana State University Frost/Freeze Data guide for information specific to your area.