There are two main techniques to start a lawn: sowing seed or laying sod.
The commonality is site and soil preparation - control weeds prior to and after establishment, create a gentle slope away from buildings (approximately one foot drop over 30 feet), and ensure a minimum six inch depth of topsoil containing at least five per cent organic matter. After that, there are advantages and disadvantages to each method.
On the one hand, seeding offers more choices in grass species and varieties. However, although cheaper than sodding, establishing a lawn from seed takes considerably longer and involves labour over an extended period.
If seeding, use high-quality Canada No. 1 grass seed. This quality designation guarantees purity (85 per cent or greater), negligible weed content (less than 0.5 per cent), and a relatively high germination rate (70 per cent).
The best time to seed a lawn is mid to late summer to avoid the spring flush of annual weeds. You should allow at least six to eight weeks before winter. Because natural rainfall is at its lowest at this time, irrigation is usually necessary during the establishment period.
Use higher seeding rates if you are unable to water; if trying to establish on slopes, banks or areas prone to erosion; or for quicker, denser establishment. Besides, lawn seed is relatively cheap.
To spread, use a cyclone-type bag spreader or a push-type centrifugal or drop spreader. For uniform distribution, start by dividing your seed into two equal amounts. Set your spreader at the lowest possible setting and distribute half in a north-south direction and the rest in an east-west direction. Use a roller to make sure the seed is in firm contact with the soil. Expect 10 to 14 days before you see any signs of growth.
Grass seedlings are very sensitive to heat and drought. Do not allow to dry out, especially during hot, dry, windy weather. Watering seedlings differs from watering an established lawn. It should be frequent and light, with little pressure and fine droplets. As the root system penetrates deeper, so should the amount and frequency of irrigation until you have a fully established lawn. An established lawn requires about one inch of water per week, taking into account rainfall.
Mowing stimulates tillering and rhizome production, increasing the density of the lawn. Mow a newly seeded lawn to three inches when the grass reaches 4.5 inches. Leaving the grass slightly longer provides a greater leaf surface area for photosynthesis and enhances rooting. Do not remove more than one-third of the leaf blade at each mowing. Ensure that your lawn mower blades are sharp. Wait to use a newly seeded lawn until after its second or third mowing.
Conversely, sod produces an almost instant lawn. It immediately reduces erosion and runoff and involves much less care and maintenance during establishment than seeding. But it is more expensive and your choice of grass is often more limited. If slopes and other difficult sites are to be grassed, sod is preferred.
You can lay sod through most of the growing season provided rooting occurs prior to freeze-up. More water will be needed in midsummer. If possible, select a sod grown in the same soil texture as in your own yard to ensure better water percolation and faster root penetration of the sod into the soil.
Good-quality sod is grown from seed under irrigation. It should be dense, uniform in size and thickness, weed free and hold together when handled. Sod should be harvested, delivered and laid within the same or next day. If left in piles, it is vulnerable to heating and drying. Upon delivery, place it in shade, cover with a tarp and lay it as quickly as possible. Purchase an extra 10 per cent to allow for waste.
Do not lay sod on dry, crusted soil. Rake and moisten the soil just prior to sodding. Begin at a building or sidewalk, laying the sod in brickwork fashion. Lay it perpendicular to slopes, starting at the bottom and working upward. Roll after laying to put the sod in firm contact with the soil. Water thoroughly, through the sod and six inches into the topsoil below. Sod has a limited root system and is vulnerable to drying out.
- Sara Williams is the author of the new and revised Creating the Prairie Xeriscape published by Coteau Books, February, 2013. This column is provided courtesy of the Saskatchewan Perennial Society (www.saskperennial.ca; email: [email protected]).
