Lawn Seed Planting Tips

If your lawn is already established and you want to replace it (without the need for leveling), we suggest the following steps:

Step 1 – Measure

Before you begin, measure the area where you plan to plant. This helps determine how much soil amendment, fertilizer, and seed you will need.
To calculate square footage (ft²), use the formula:

Length (ft) × Width (ft) = Square Feet (ft²)

Be sure to save your notes in a safe place for future reference.

Step 2 – Test the Soil

It’s best to perform a soil test 1–2 months before planting. These tests take time to process but allow you to prepare with the proper amendments for successful growth.

• Contact your local county extension office to find out where to send your samples
• Use a local soil testing lab for results that are more specific to your region.
• Take multiple samples from various locations in your lawn for accuracy.
• Soil samples should be collected from the top 6–8 inches.
• Less accurate soil test kits are also sometimes available from local lawn and garden suppliers or can be found online
• Currently, as of 2025 basic soil tests range from $10-30 per sample but can be $30 up to $150 the more comprehensive tests you request. So expect to pay roughly $10-$150+ depending on your needs.

Step 3 – Weed Control

Choose one of the following weed control methods. Based on our experience, completing this step in fall and waiting to replant in early spring provides the best results.

Option 1 – Organic Top Layer (No Herbicide)

Apply 2–4 inches of peat moss, fine bark dust, or potting soil over the existing soil without mixing it in. This creates a clean planting surface and seals off weed seeds in the original soil.

• Fine sawdust is the most economical.
• Peat moss is mid-range in price.
• Potting soil is the most expensive but may offer the best seed-starting conditions.

Option 2 – Herbicide Application

Use a non-selective herbicide to kill existing vegetation. This method is quicker and often less expensive, but requires caution:

• Wait at least 3 days after mowing before applying the herbicide.
• Follow label instructions precisely.
• After the recommended waiting period, mow again as short as possible.
• Remove debris (you can compost it).
• Optionally, use a thatcher blade to loosen the surface again.
• For a natural alternative, undiluted apple cider vinegar may help control many weeds.

Option 3 – Clear Plastic Solarization

Cover the area completely with clear plastic sheets for 6–8 weeks to suffocate weeds and grass. This is time-intensive and can be expensive, but highly effective.

• Best performed during the growing season for maximum heat retention.
• Less effective in cooler Northwest climates, but still useful for partial control.

After the plastic is removed, continue to Step 4.

Step 4 – Work the Soil

Be cautious when working wet soil. Overworking wet ground can cause long-term soil structure damage.

Use this quick test:

• Squeeze a handful of soil into a ball.
• Drop it onto a hard surface.
• If it stays in a ball and doesn’t crumble, it’s too wet to work.

Once conditions are right:

• Loosen the top 1 inch of soil using a cutter or tiller.
• Do not till deeper—this may bring weed seeds to the surface.

Step 5 – Rake and Fertilize

• Rake and level the soil, removing heavier debris.
• Apply a thin layer (approx. ¼ inch) of clean peat moss or sawdust. Make sure the material is weed-seed free.
• Use a leaf rake to smooth and level.
• If needed, apply lime or gypsum at this time.
  • Pelletized or granular lime is easiest to apply.
• Spread amendments evenly using a fertilizer spreader for consistent coverage and to create a uniform planting bed.

If you’re waiting until spring to plant, stop here. Continue to Step 6 closer to planting time.

Step 6 – Weed Control, Part 2

If you’re still concerned about weeds:

1. After you’ve thatched, leveled, and added amendments, begin watering the area lightly.
2. Keep the soil evenly moist for about 2 weeks.
   1. Water when the soil is dry by afternoon but still moist in the morning.
   2. Avoid overwatering—pooling will suffocate emerging seedlings.
3. If watering isn’t possible, let the area sit idle for 2–3 weeks.
   1. This allows weed seeds near the surface to germinate.
4. After several days of 50–60°F daytime temperatures, inspect for weed growth.
   1. If no weeds appear, you’re ready to move on to Step 7 (top coating and seeding).

Optional Re-Treatment with Clear Plastic:

If weeds reappear, repeat Step 3 (plastic cover) for another 2–4 weeks. This extended period increases weed control, especially during warm, sunny weather. Be sure the plastic remains sealed tightly.

If not using plastic, rake up or pull out any new weeds by hand or hoe. Avoid disturbing the soil too much, as this can bring up more weed seeds.

Optional Top Layer:

Apply a ½-inch layer of peat moss or sawdust to the planting area. This helps suppress any remaining weeds and provides a fine-textured seed bed for your grass seed. Smooth with a leaf rake—you’re now ready to plant.

Repeating Weed Control – Clear Plastic Method

With the clear plastic method, after two weeks have passed, you can repeat Step 3 by re-covering the area with plastic. This helps control any new weeds that have surfaced since the soil was last disturbed. Keep the plastic in place for another 2–4 weeks, depending on how thorough you want your weed control to be—the longer the better.

For best results, this method should be done during the growing season, and the plastic must remain sealed tightly around the edges.

This approach can be difficult due to the patience required, but the payoff is a clean, beautiful lawn that lasts much longer.

If You Skip the Plastic…

If you choose not to use plastic:

• Lightly rake weeds with a leaf rake, or remove them by hand or with a hoe.
• Try to disturb the soil as little as possible, as doing so may bring more weed seeds to the surface.

If you’re applying peat moss or sawdust, spread it at about ½″ deep over the planting area. This helps:

• Suppress remaining weeds.
• Provide a fine seed-starting medium.

Level and smooth the area with a leaf rake—you’re now ready to plant.

Planting Grass

Now it’s time to seed your lawn:

1. Using a fertilizer spreader, apply half of your seed walking in one direction (e.g., north to south).
2. Apply the remaining half walking perpendicular to the first pass (e.g., east to west).
3. If you have leftover seed, save it for touch-ups later.

You can lightly firm the seed into the soil using a leaf rake or roller, but this step is optional.

The seed should be very shallow, just resting on the surface—no deeper than the length of the seed itself. If you see seed on top of the soil, that’s okay! Good seed to soil contact is important though.

The recommended seeding rates are minimums—performance may improve with slightly higher rates.

Watering After Seeding

• Keep the soil moist for the first 2–3 weeks after planting.
• Re-water when the soil appears dry in the morning.
• Avoid overwatering or allowing water to pool, as this can create dead spots.
• Water lightly and frequently to keep the upper layer of soil moist.

Once seedlings emerge:

• Reduce watering gradually.
• Allow the soil to dry slightly between watering, which encourages deeper root growth.

New Lawns

If you’re starting a brand new lawn:

1. Level and smooth the soil to your preferred grade.
2. Ensure there’s good-quality topsoil over any poor clay or rocky subsoil.
3. Water the area for 2–3 weeks, as if it were already planted, to germinate any weeds. There are most likely dormant weed seeds in the soil of your lawn. Whenever you disturb your soil you bring up weed seeds to the surface that can sprout and compete with your lawn.
4. Avoid pooling.
5. Let the top dry out slightly, then choose a weed control method from “Planning and Preparing for Renovating a Lawn” above.
6. Afterward, top coat with less than ½″ of clean peat moss or sawdust to create a smooth, weed-free seed bed.

Primary Planting Season: Late Summer to Early Fall

• Timing: Mid-August through mid-October
• Ideal Soil Temperature: 50°F to 65°F
• Why It’s Best:
  • Warm soil encourages fast germination.
  • Cooler air temperatures reduce heat stress.
  • Fewer weeds compete with new seedlings.
  • More consistent rainfall helps establishment.

Secondary Planting Season: Early to Mid-Spring

• Timing: Late March through May (varies by region)
• Ideal Soil Temperature: 50°F to 65°F
• Pros:
  • Good for patching or if fall was missed.
  • Cool temps support growth.
• Cons:
  • More weed pressure.
  • Summer heat may arrive before grass is well established.

Best Practice:

If you plant in spring, consider:

• Using a starter fertilizer.
• Overseeding again in fall to improve density and weed resistance.

Repairing Spots in Established Lawns

To repair damaged patches:

1. Remove weeds or unwanted grass.
2. Lightly scratch the soil with a hoe or rake (no deeper than 1 inch).
3. Spread 1 inch of potting soil, peat moss, or sawdust on top (do not mix with the soil).
4. Level and rake smooth.
5. Apply seed using a shaker container (we offer this on our website) or sprinkle by hand.
6. Keep moist until established.

Best done in spring or fall for best results.

Fertilizing Your Lawn

• Use fertilizer at lower rates, applied more frequently to avoid nutrient runoff.
• Wait until your lawn is growing well—usually after the first or second mowing—before applying fertilizer.
• Follow product label directions carefully.
• We recommend using less than the suggested amount, applied more often.

A slow-release fertilizer is a safe and environmentally friendly option. It keeps your lawn greener, longer, without the risk of burning.

Analogy: Lawns are like people—they don’t just eat once a week. Soil is like your kitchen; it holds only so much food and needs replenishing as nutrients are depleted (especially when mowing frequently).

Watering Established Lawns

As your lawn becomes established:

• Water based on weather conditions.
• In hot, dry conditions, you’ll need to water more often.
• Watch for dry spots, especially under trees or in shallow soil areas.

A good rule of thumb:
In the Northwest, your lawn should receive about 1 inch of water per week (the amount it takes to fill a tuna can under your sprinkler).

• Water deeply and less frequently for better root growth and disease resistance.
• Best time to water: Early morning.

Too little water = dry, brittle lawn
Too much water = yellowing, nutrient loss, more mowing, and weed growth

Mowing Tips

• Wait until grass is well-established before first mowing.
• Mow to 1½″–2″ height, and never remove more than 1/3 of the plant height at once.
  • (Example: When grass is 3″, cut to 2″)
• Regular mowing helps maintain plant health and prevents stress and discoloration.

Cultural Practices

• Keep mower blades sharp to avoid damaging leaf tips.
• Fertilize regularly (in smaller doses) to maintain health and color.
• Mulch grass clippings if mowing frequently; otherwise, collect and compost.
• Avoid excess watering to prevent nutrient leaching and disease.
• Water deeply (about 1″/week) to promote deep roots and drought tolerance.

Best planting times (Pacific Northwest):

• Spring: April – May
• Fall: September – October

Weed Control in Established Lawns

A healthy lawn will naturally suppress many weeds.
For broadleaf weeds, consider:
Weed-and-feed fertilizers (follow label rates)
Hand-pulling or hoeing
Grass-type weeds are more difficult and may require:
Spot spraying
Manual removal
Even with preventative measures, some weed seeds are dormant or hard-shelled and may sprout over time.

Pests and Disease

Even well-maintained lawns can suffer from:

• Weather-related stress
• Soil issues
• Pest infestations

If you encounter a specific problem, feel free to contact us via email for help identifying and addressing it or visit the Oregon State University Extension Service.

Common issues:

• Earthworms can attract moles, which disturb the soil.
  • A sign of a healthy lawn, but moles can be a nuisance.
• Slugs, common in the Northwest, can feed on grass.

Healthier soils—thanks to fewer chemicals and better crop rotation—often bring better results and better grass.

Overseeding Cool-Season Lawns

To rejuvenate your lawn:

1. Mow grass as short as possible or use a vertical-cut (dethatching) machine.
2. Rake thoroughly and remove all debris.
3. Loosen the soil slightly to allow seeds to take root.
4. Apply 2–3× the normal seeding rate:
   1. Half in one direction
   2. Half in the opposite direction

Use a broadcaster fertilizer spreader for uniform seed distribution. (Follow the manufacturers instructions).

Best times to overseed cool-season lawns:

• Fall (ideal): October–November
  (Cool-season grasses germinate best when soil temperatures are between 50°F and 65°F.)
• Spring (Pacific Northwest): Late March through May
  (Spring seeding is also effective in the PNW, although fall is generally preferred for reduced weed competition and better root development.)

Dethatching

Dethatching a lawn is necessary when excess debris has built up and prevents your lawn from growing properly. This layer of thatch can block nutrients, water, and air from reaching the soil and grassroots. In extreme cases, your lawn can nearly die out due to thick mats of dead roots, clippings, and other debris.

To fix this, dethatch and remove the debris. The best times to dethatch are in the fall or spring, when grass growth slows down. Dethatching at the right time will revitalize your lawn and improve its overall health.

Aerating

In areas with high foot traffic, soil can become compacted, preventing water, air, and nutrients from reaching the roots. Older lawns are especially susceptible because of built-up root mass and organic matter over time.

If you’re replacing your lawn or overseeding, aerating beforehand will greatly increase your chances of success. Aerators create holes in the soil to loosen it and promote healthy root development. These machines can typically be rented from local equipment rental stores.

Debris

Avoid leaving debris on your lawn that covers or smothers the grass blades. Whether it’s leaves, pine needles, clippings, or other yard waste, too much can block sunlight and airflow. This can damage the lawn or lead to dead patches.

Tip: Regular raking and light cleanup during the growing season will help keep your lawn healthy and vibrant. Also make sure you keep leaves raked up and off the lawn if you have trees loosing their leaves in the area.

Shade

If you have shady areas, such as under trees, consider using a special seed mix formulated for low-light conditions. Grass in shaded areas competes with tree roots for moisture and nutrients, so these zones may require extra care and maintenance.

Different tree types and sizes will affect your lawn differently, so monitor those areas closely.

Top Cool-Season Grasses for Shade

1. Fine Fescues

Fine fescues are widely regarded as the best cool-season grasses for shade tolerance.

• Types:
  • Creeping Red Fescue
  • Chewings Fescue
  • Hard Fescue
  • Sheep Fescue
  • Shade Tolerance: Excellent
• Mowing Height: 2.5″–3.5″
• Ideal Use: Shaded or low-maintenance areas; mixes well with other cool-season grasses
• Other Notes: Requires less fertilizer and water than other grasses

2. Tall Fescue (Turf-Type Varieties)

• Shade Tolerance: Moderate to Good
• Mowing Height: 3″–4″
• Ideal Use: Areas with partial sun to moderate shade
• Other Notes: Deep roots make it drought-tolerant; prefers more sunlight than fine fescue

3. Perennial Ryegrass

• Shade Tolerance: Fair (performs better in sun or light shade)
• Mowing Height: 2″–3″
• Ideal Use: Overseeding and quick establishment in areas with partial sun
• Other Notes: Fast germination, but not ideal for dense shade

4. Kentucky Bluegrass (Shade-Tolerant Cultivars)

• Shade Tolerance: Poor to Fair (some improved cultivars have better performance in partial shade)
• Mowing Height: 2.5″–3″
• Other Notes: Spreads via rhizomes, slow to establish, not ideal for deep shade

Tip: Avoid using Kentucky Bluegrass in full-shade areas unless you use a specially bred shade-tolerant variety.

Common Causes of Lawn Failure

Here are the most frequent reasons lawns fail to thrive:
Poorly prepared soil
Inadequate moisture
Excessive moisture or pooling
Improper planting time
Adverse weather conditions
Impatience (not giving seeds time to establish)
Low-quality or poor soils
Addressing these issues ahead of time can save you effort and money in the long run.

Lawn Mixes

In regions like the Pacific Northwest, maintaining a premium lawn often means you’ll need to overseed or fully renovate your lawn every 3–5 years—though with good maintenance, some lawns can last even longer. In southern climates, overseeding is typically required annually.

Lawn and weed growth are both temperature-dependent, so timing is key for both seeding and weed control.

Composting Tip

The clippings, leaves, and roots removed during lawn care projects make excellent material for composting and can be used later as a soil amendment.

About Our Lawn Seed Mixes

• The lawn blends we provide are carefully formulated to offer optimal turf performance for lawns in the Northern U.S. because our lawn seed is considered cool-season type turf grass. If you are located in the Southern U.S., you will most likely need a warm-season grass for best results. In that case, we recommend locating a seed company or supplier that specializes in warm-season lawn seed varieties.
• We use a mix of high-quality grass seed varieties, not poor-quality filler.
• Each blend is designed to balance adaptation, durability, and appearance.
• Different environments and applications may require different grass traits, which is why blends are superior to single-variety seed in most situations.

Our goal is to offer seed blends that help you create a healthy, long-lasting, and beautiful lawn—whatever your location or lawn goals may be.

Need Help?

We hope the information on this page helps you achieve the lawn you’re aiming for. If you have any questions along the way, just drop us a note—we’re happy to help!

For more detailed guidance on lawn care in the Pacific Northwest, visit the Oregon State University Extension website. This website is as great resource listing images and data for possible diseases, pests or problems you may be experiencing.

OSU Extension – Practical Lawn Care for Western Oregon