Planting a lawn from seed is an attractive option for many do-it-yourself landscapers because it is less expensive and labour intensive than buying and hauling in rolls of sod. Growing grass seed presents its own set of problems, however. Birds make a habit of eating the seed, and the seed needs to be kept moist and relatively warm almost all the time in order to have successful germination. Using plastic sheeting over the grass seed is an effective way of dealing with these problems and makes growing grass from seed much easier.
Plan your seeding with plastic sheets for the cooler periods in the spring or autumn. Summer temperatures will cause the area under the plastic to get too hot. Select an area with soil that is well drained.
Apply a lawn starter fertiliser to the planting area, and till the soil down to a depth of 10 cm (4 inches). Dampen the soil with water so seed will stick well when spread.
Spread the seeds at the prescribed rate for the grass variety you have selected using a mechanical spreader. Apply half of the seed in one direction, then the other half at a 90 degree angle to the first application.
Use a rake to work the seeds into the top layer of soil. Roll the area with a seed roller. Wet the area down so that it is thoroughly damp, but not soggy.
Add a 2.5 cm (1 inch) layer of straw mulch to the entire area, and again spray it down lightly with water.
Roll out clear plastic sheeting over the seeded area, overlapping the edges of individual sheets by a couple of inches. Hold down the edges of the plastic with pieces of lumber, rocks, bricks or any other heavy objects that will make it easy to pull the plastic back and forth over the seeded area.
Monitor the moisture level of the seeded area every day. It should be consistently damp for the seeds to germinate. The plastic will trap moisture and condensation, meaning you will have to apply water much less often than you normally would. Occasionally you may need to pull back the plastic, spray down the area and replace the plastic sheets.