Coverage: 500 sqft per bale (average)
While not entirely necessary, straw can improve the germination rate of your grass. Here are the benefits of using straw to cover grass seed:
Prior to germination, however, newly-planted grass seeds are highly vulnerable to being blown away or washed away by wind and rainwater. This leaves you with patchy turf that has unsightly bare spots in the sections where the seeds were blown away.
Another reason to cover your newly-seeded lawn with straw mulching is to prevent the grass seeds from damage due to excessive exposure to sunlight. Straw also acts as a visual screen to discourage birds and other small animals from digging holes and feeding on the newly-planted grass seeds.
Finally, as the straw decomposes over time, it adds nutrients into the soil, which is beneficial for the growth of the newly-planted grass seeds.
Unlike newly-planted trees and shrubs that are typically covered with a thick layer of mulching, grass seed doesn’t require as much covering. Applying an excessively thick layer of straw over your newly-seeded lawn will inhibit seed growth by preventing much-needed sunlight from reaching the soil.
A thick layer of straw – with its excessive moisture retention properties – makes for a perfect habitat for the growth of fungal organisms like mushrooms. These fungi further choke out your growing grass seeds, thus inhibiting seedling development.
For improved grass seed germination, ensure that the layer of straw that you apply over your newly-seeded lawn is no more than three inches thick. Usually, a single bale of straw should be enough to cover about 500 square feet of lawn area lightly. Applying more straw than this will encourage fungal infestation, while applying less will likely lead to bare spots on the lawn.
The rule of thumb is this: if you can’t see the soil through your straw covering, you’ve probably applied too much and should cut back on some of it.