If you're looking for ways to extend the growing season, techniques that allow you to plant your vegetable seedlings before the last frost in the spring will help. Although there is always some risk involved, as weather can be unpredictable and the temperatures can dip lower than expected, using plastic milk jugs as hot tents will provide protection from temperatures as low as 29 to 30 degrees Fahrenheit, advises Iowa State University Extension and Outreach. Milk jugs will also protect young seedlings from chilling winds and rain as they become established in the garden.
Wash the milk jugs in hot, soapy water to remove any milk residue. Rinse them with hot water and allow them to air dry. Unwashed milk jugs develop a sour, unpleasant smell that is difficult to remove from the plastic.
Cut the bottom off the plastic milk jug with a sharp knife.
Position the milk jug over the top of the seedlings when you plant them in the garden, pushing the bottom rim of the milk jug into the soil 1 to 2 inches to anchor it in place.
Drive a dowel or plant stake through the hole in the top of the milk jug and into the soil, taking care not to damage the seedlings or their roots. This prevents the milk jug from being blown off in the wind.
Mound soil around outside base of the milk jug and firm it down with your hands to further provide stability for the milk jug.
Remove the milk jugs from your seedlings in seven to 10 days, or whenever the weather warms. Plants allowed to remain in the hot tent for too long produce a smaller yield, notes Iowa State University Extension and Outreach.