Can you seed a lawn too much?

Quick Answer

Yes, it is possible to seed a lawn too much. Over-seeding can lead to problems like overcrowding, disease, and thinning of the grass. The ideal seeding rate depends on the type of grass, weather and soil conditions, time of year, and other factors. As a general rule, 2 to 6 pounds of seed per 1000 square feet is sufficient for new lawns or overseeding existing lawns. Excessive seeding rates beyond this can cause competition between grass plants for resources like sunlight, water and nutrients. Moderation is key when seeding to avoid wasting seed and negatively impacting lawn health.

What happens if you put too much grass seed down?

Here are some potential issues that can arise from using excessive grass seed:

Overcrowding and thinning

Too much seed leads to overcrowded grass plants once the seeds germinate and sprout. This causes the plants to compete for resources and many will be malnourished and weak. Overcrowding prevents the plants from developing strong roots and blades. It also opens up the lawn to disease and insect problems that can spread quickly between grass plants. The end result is thinning out of the lawn over time.

Wasted seed and money

Grass seed can be expensive, especially varieties like Bermuda and zoysia. Using more than the recommended seeding rate ends up being wasteful and cost prohibitive. Not all the seed will germinate when over-seeded, so the excess ends up going to waste.

Uneven growth

Too much seed can result in patchy growth across the lawn. Some areas will be overloaded while other spots are underseeded. This leads to uneven texture and growth across the lawn. It looks unsightly and can be difficult to correct once established.

Poor germination rates

Heavy over-seeding can actually lead to lower germination rates. Too many seeds clumped together causes them to compete for resources. This leads to fewer seeds properly sprouting and developing. Spreading seed too thickly can also result in mold growth which impacts germination.

Damage to existing grass

If over-seeding an existing lawn, too much seed can smother and damage the established grass. The existing lawn needs adequate sunlight, air circulation and water to thrive. Excessive seeding prevents proper resources from reaching the original grass.

Loss of seed

Heavy seeding can result in seed runoff, especially on sloped lawns. Rain and watering can wash away the excess seed before it has a chance to germinate. Seed is also lost from being blown away or consumed by birds and animals when applied too heavily.

Mushy lawn

Too much seed leads to overcrowded seedlings and shallow roots. This causes the lawn to be less hardy and mushy underfoot, especially in wet weather. It’s more prone to compaction and damage from use. Grass plants require adequate space for the roots to strengthen.

Waste of time and effort

Applying seed properly over a lawn takes time and effort. Having to re-seed areas that fail due to overcrowding ends up being a waste of time. It’s important to get the seeding rate right the first time.

What is the ideal grass seeding rate?

The ideal grass seeding rate depends on several factors:

Type of grass

The recommended seeding rate varies based on grass species. For example, Bermuda and zoysia grasses require 2-3 lbs per 1000 sq ft. Cool season grasses like fescue and bluegrass do better with 5-6 lbs per 1000 sq ft. Always follow seeding instructions for the specific grass variety.

New lawn vs overseeding

New lawns require heavier seeding than overseeding existing turf. For new lawns, aim for 4-6 lbs per 1000 sq ft. When overseeding, 2-4 lbs per 1000 sq ft is sufficient. The existing grass already occupies some of the space.

Time of year

Spring and fall are the best times for seeding cool season grasses. Warmer months favor warm season grasses. Adjust rates accordingly. Hot weather calls for slightly higher rates to account for less favorable growing conditions.

Soil quality

Loose, rich soil needs less seed than compacted or sandy soils that offer less organic matter. Enhance poor soils with compost or topsoil to optimize growth. This allows for lower seeding rates.

Sunlight exposure

Shady lawns should be seeded more heavily than those getting full sun. Grass needs ample sunlight, so more seeds compensate for lower light.

Size of lawn

Larger open lawns require slightly less seed than small confined yards. Air circulation is better over large areas.

Slope of lawn

Use higher rates on steep hills and slopes to account for some seed runoff. Flat, level lawns need less seed.

Signs your lawn is over-seeded

Here are some telltale signs that too much grass seed has been applied:

– Excessive thickness, almost like a marshy mat of grass

– Grass seems to grow vertically faster than it spreads

– Lawn appears lush and green initially but then thins out

– Grass feels spongy and wet underfoot

– Roots are shallow and easily pulled up

– Seedlings appear crowded and clumped together

– Lawn is patchy with bare spots developing

– Significant mold, disease or fungal issues

– Grass blades appear yellowed or starved for nutrients

– Seed washed off slopes or low areas after rainfall or watering

If your newly seeded lawn exhibits some of these warning signs, over-seeding is likely the culprit.

Correcting an over-seeded lawn

Here are some tips to address a lawn that’s been over-seeded:

Let it grow in

Allow the existing seedlings to establish deeper roots and wait for thinning. Gradually some of the overcrowding resolves on its own over time.

Overseed sparingly

You can overseed again lightly in bare spots at a lower, ideal rate. This helps fill in without worsening the heavy seeding.

Aerate the lawn

Use core or spike aeration to relieve soil compaction and improve drainage and air circulation. This alleviates thinning related to overcrowding.

Apply fertilizer

Fertilizing sparingly provides nutrients to stunted, malnourished grass. Avoid excessive nitrogen.


Thatch buildup often accompanies over-seeding. De-thatching clears matted layers to allow seeds better contact with soil below.

Top dress

Adding a thin layer of compost over the lawn improves moisture retention and organic material in the soil.

Adjust soil pH

Test pH and correct acidity or alkalinity levels in the soil. Proper pH greatly aids seed germination and development.

Re-sod damaged areas

Sections of the lawn that fail to recover may need re-sodding to restore growth. First address what caused the original damage.

Reseed completely

In severe cases, it may be necessary to till up the lawn, amend the soil and re-seed the entire area at a proper rate.

How to prevent over-seeding

Here are some tips for seeding at the ideal rate:

Measure lawn area

Know the square footage of the lawn. This allows you to accurately calculate how much seed is needed.

Use a seed spreader

Spread seed evenly using a broadcast spreader. Well-calibrated models allow you to set your ideal rate.

Apply half the seed per direction

Divide the total seed amount in half and apply in two directions – vertically and horizontally. This ensures even coverage.

Avoid windy conditions

Wind causes heavy seed to blow into piles leading to wasted seed and patchy growth.

Water seed gently

Light, frequent watering is best. Heavy watering can cause seed runoff, especially on slopes and hills.

Follow seed label rates

Recommended rates vary, so check the label on your specific grass seed variety. Never exceed recommendations.

Wait proper time to re-seed

If over-seeding, wait at least 30-60 days before reapplying more seed to prevent excessive buildup.


Proper seeding rates are crucial for a healthy, lush lawn. Excessive seeding can have detrimental effects like overcrowding, poor germination, disease and wasted seed. For the average lawn, aim for 2-6 lbs of grass seed per 1000 square feet depending on your specific conditions and variety. Be sure to spread seed evenly in two directions across the lawn. Follow label instructions, and don’t over-seed within 60 days to prevent problems. With careful seeding, you can achieve a robust, beautiful lawn that thrives for years to come.

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