Frost is imminent but you do not have to yield your still producing or ripening vegetables to it. We LOVE our 1.5 oz. Frost Protection Fabric, a medium weight, breathable, permeable, UV treated spunbonded polyester fabric designed to protect crop plants from freezing, drying and extreme temperatures. Usually referred to as Floating Row Cover, it creates a warmer microclimate by capturing heat of the the day - and then slowing the loss of stored heat at night so it raises minimum temperatures, without suffocating, crushing or burning plants the way plastic could. If days are warm, it is better to remove the fabric during the day and to cover well before nightfall. Its light density and permeability allow air, water and sunlight through so plants can flourish beneath it even if left on for weeks. Remember: there is no such thing as cold, just less heat. The trick is to collect the day's heat and trap it for the night.
Protect tender flowers from the frequent the late frosts of spring. Even use it over apple trees and lilacs to save the buds (more). Use it in summer to protect plants from hail storms (leave it on for days). Use it for flower boxes, vegetable gardens, row crops, fruit trees and flowering and fruiting shrubs (in a pinch, it can be used as filter fabric or a liner for moss baskets).
In the past few years MANY gardeners, with full-sun gardens have been using the row-cover all summer (like a greenhouse cover) with excellent (actually far superior) results. The fact that the 1.5oz fabric cuts ~50% of the sunlight is more a benefit than a disadvantage in our high elevation gardens.
In Autumn, your vegetable harvest time and blooming plant season can be extended by a month or more. When it gets really cold, double up the layers and leave a string of C7 or C9 Christmas lights on around your plants at night. We tested dozens of brands and weights and have been delighted with the durability and effectiveness of the one we now use. Our bulk rolls are 12' wide by 300' long but we sell any length. Our pre-cut packages are 12' x 10'.
1.) Drape over the plants to be protected. Support with stakes over (not touching) the plants if hard frost is expected.
2.) Remove when weather improves. In early spring and late fall, garden plants thrive under the row cover for weeks on end. After use, store out of direct sunlight (we use clean / new garbage cans to store ours... keeps out sun, rain and rodents).
BTW, there is evidence to show that fertilizing your plants with seaweed gives them an extra measure of frost resistance (as well as providing micronutrients, improving flavors, strengthening stems and cell walls, and helping plants fight insects and diseases). Kelp Meal, Maxicrop, etc... can be used ANY time of year. It is usually my first feeding of the year and often my last as well... (besides the BIOSOL on the lawn in November).