Many vegetables such as tomatoes, peppers and eggplant cannot be planted in the garden until after all danger of frost has passed. It is possible, however, to get an early start using plastic structures called Wall O Waters.
About 18 inches high and about 15 inches in diameter, it consists of a ring of tubes which you fill with water. During the day, the sun heats the water. During the night the heated water keeps the plants warm. I have used them successfully during quite heavy frosts and have gathered tomatoes in June.
Tips on using them:
Filling Tips:
Reminder: Do not try completely filling the tubes from the beginning. The "wall" will fall over and crush the plant. Go round as I have explained and it will remain stable.When the time comes to remove the unit, the best way I have found is to grasp the top firmly on both sides and lift straight up and drop it clear of the plant and the water will drain out. With a little care the units will last for years.
I have found the best varieties for early tomatoes are "July Fourth" and "Alicante."
The Wall O Waters can be obtained from Gardener's Supply or Burpee