How Do You Build A Greenhouse Using Polythene?
The following instructions are for a 28′ x 15′ greenhouse. The land the greenhouse sits on does not have to be prepared in advance; in fact, you can plant directly into the ground inside the greenhouse. Expect the polythene to last about four years. Yellowing or cracking means the plastic needs to be replaced. Polythene does not provide the protection glass does; however, Northern gardeners can still harvest cold weather crops like spinach, kale and carrots in the winter. Many gardeners use this type of greenhouse like an enormous cold frame, hardening off seedlings in the spring and summer and overwintering hardy veggies and tender perennials in the winter. Check your city or county ordinances for restrictions or permits you must have to build the greenhouse. Choose a spot that is level, well drained and away from trees and shadows and close to your outdoor water supply. Using your string and stakes, mark out the long sides (28 feet) of your greenhouse and pound in the re-bar lengths
