The vented covers have many purposes.
An important purpose of the cover is to protect the seeds.
With covers:
The seeds can't be washed out of the soil by a downpour of rain.
Weed seeds can't be washed in.
The soil surface is protected from nearly all wind-carried seeds.
Hungry birds, critters and bugs can't get to the seeds and eat them.
We put small slits or holes in the covers so:
Air that has been warmed by the sun can vent away.
Rain or melting snow will seep into the container and keep the soil moist.
Stiff winds are deflected, which helps to reduce drying of the soil surface
An exchange of fresh air can prevent damping-off.
Favourable Seed Propgation Environments
Germinating the Seeds
Raising Seedlings of Tropical Seeds
FAO.Org
Beyond Seeds: Getting Your Seeds to Grow into Plants
by Jill Nokes
Native Plant Production
Environmental Horticulture
College of Forest Resources
University of Washington
Moisture and Watering
WinterSown.Org
Damping-off Diseases in the Garden Management Guidelines
Pests in the Gardens and Landscapes
How to Manage Pests
Statewide Integrated Pest Management Program
Agriculture and Natural Resouces
University of California
