Grass Lawn

Installing a Seed Lawn

Tips for Installing

The optimal time to seed a lawn in the Pacific Northwest is between Sept. 1st and Oct. 15; but second best is between April 15th and June 15th.

  1. Calculate the square footage of space for your new lawn. To figure square footage, simply multiply the length and width.
  2. Examine the amount of light the area receives. There are seed mixes for every kind of situation. Shade, sun, high traffic, water conservation, and environmentally sound seeds are now available.
  3. Prepare your soil for the seed (or sod).
    • Roto-till when the soil is not too wet.
    • Add compost to help increase drainage (air and water flow) through the soil.
    • Add lime to raise the pH level, 5lbs. per 100 square feet
    • Use the roto-tiller to blend lime and compost

Equipment Needed

  • Rototiller
  • Steel Lawn Rake
  • Drop Spreader
  • Water Roller

Portland Nursery has lawn rakes, rollers, and spreaders available for use with a refundable deposit. Please call ahead to be sure they are available for use.

Rototillers can be rented at any equipment rental store.

Steps for Seeding a Lawn

Remove old turf

There are a couple of ways to remove old or unwanted turf.

Sheet mulching the entire area in the spring or fall will slowly smother out the turf underneath. This leaves an area ready to dig in organic matter and prepared for seeding.

A quicker option is to use a non-selective herbicide. There are chemical and natural options and should be applied 2-3 weeks ahead of time when the air temps are between 50-80 degrees. Once the grass is dead, rototill no deeper than 6" and hand remove any large clumps that won't break up.

This is also a good time to add amendments such as lime and compost.

Level the bed and sow seed

Use a steel lawn rake to even out the soil and remove stones. This will help attain a flat surface and will provide superior germination results. Add lime, 50# per 1000 sq. ft to sweeten the soil. Sprinkle over area to be seeded and rake into the surface.

Divide the seed into two lots. Using a drop spreader, distribute the first lot, then distribute the second lot at right angles to the first. In smaller areas, this can be done by using a handheld spreader or by hand. When using a drop spreader, make sure the edges are touched up by hand.

Rake in seed and roll

Lightly rake the entire area to ensure good contact between the seed and soil. The depth of the seed should be between 1/8 to 1/4 inch. Use a water roller, to compact the entire area. This will help the seed assimilate more water and quicken germination time.

Add mulch or compost

This will also speed up germination and keep the birds from eating seed. If the area is on a slope, this will help keep the seed in place and prevent erosion. The mulch should be spread thin enough to see the soil underneath.

Water thoroughly

Sown lawns must be kept constantly moist. Thoroughly soak the area after planting to a depth of 6 inches. Water by hand two to three times a day. This should be done more often when it’s hot and/or windy, and should be applied using a fine spray so that the seed is not disturbed. It is important to keep the area free of any traffic for at least 6-8 weeks.

Only after this period of time should gentle mowing commence. The soil will be soft and the grass will be more delicate than an established lawn.


Knowing what a lawn likes goes a long way to creating that great looking patch of green.

  • Soil pH of 6.5-7
  • Lime 5lbs. per 100 square feet, twice a year. Our rainy climate leaves soil with a low pH, making it hard for lawn grass to pick up the nutrition it needs to thrive. Raise the pH by adding lime twice a year and your lawn will be much healthier.Lawn
  • Water 1" per week In summer, watering this much will allow the lawn to go dormant, which is healthy. Letting the lawn grow taller in hot summer months, 3-4" keeps it looking greener.
  • Fertilize 3x per year with organic fertilizer or 4x per year with synthetic fertilizer. Start in March, finish in September.


A 7-10 pound bag of seed will cover 1000 square feet.

Sun and Shade Mixes contain:

Perennial Rye grasses are softer and thinner than fescue and require more fertilizer and water. Less shade tolerance.

Fescue grasses have thicker harder blades, shade, drought and traffic tolerant.

Tuff Turf contains:

Fescue grasses with thicker harder blades, good drought, traffic tolerance. Can take sun or shade.

Water Warden contains:

Hard, tall fescue which take drought and traffic. Tolerates sun and shade.

Envirolawn contains:

Fescue, Yarrow, Ryegrass, Strawberry Clover, White Alyssum, English Daisy. This mix has many flowers which can be mowed and is drought and traffic tolerant. Best for sun, but will tolerate some shade.


Portland Nursery carries a variety of high quality seed mixes blended for Pacific Northwest conditions.

  • Water Warden – slow-grow, low water option.
  • Envirolawn – blend of grass, clover and flower seeds.
  • Sun, shade or blended sun and shade.

Choose the seed that suits your site's requirements and follow the 5 steps on our Installing a Seed Lawn Brochure.

Download one of our Handouts for Lawn Substitutes:

Lawn Substitutes & Path ground covers for Shade

Lawn Substitutes & Path ground covers for sun

  • Remove moss – use a moss killer & rake out the remains once moss has turned black (about 2 weeks).
  • Remove or kill weeds
  • Remove thatch using a thatch rake. This will also rough the surface of the soil for planting.
  • Aerate soil if the ground is poorly drained. Use compost or pumice to fill aeration holes.
  • Add soil in low parts of the lawn to level the planting area.
  • Add lime, 5lbs. per 100 sq. ft.
  • Sow seed using a seed blend that suits your sun exposure. Use a seed broadcaster at a rate of 3lbs. per 100 sq. ft.
  • Fertilize following the directions on your fertilizer package.
  • Cover seed lightly with compost, no thicker than 1/8" to protect from birds & erosion.
  • Water, keeping seed consistently moist.
  • Mow when grass is 1 ½" tall.

Find the Perfect Grasses for your Garden

Grasses are a great choice to add structure, color and movement to the garden.

Work them into any garden style as focal points or accents and you'll be delighted with their graceful ease.