When planting new grass seed, it is important to cover the seed properly to help retain moisture, maintain soil temperature, and protect the seed from birds. There are several effective options for covering grass seed, but choosing the right material depends on factors like your climate, soil type, and budget.
Should I Cover Grass Seed?
Covering newly planted grass seed has several benefits:
- Retains moisture – Grass seeds need consistent moisture to germinate and become established. Covering the seeds helps retain moisture near the soil surface.
- Regulates soil temperature – Bare soil can become too hot or cold for seed germination. An organic cover moderates soil temperature.
- Prevents washout – Uncovered seeds can be washed away by heavy rain or irrigation. A cover protects seeds from displacement.
- Deters birds – Birds love to eat grass seed. Covering deters birds from feasting on seeds.
Due to these benefits, experts recommend covering newly seeded areas with some type of material rather than leaving seeds exposed.
Best Options for Covering Grass Seed
Straw
Straw is one of the most commonly used covers for newly seeded lawns. Straw comes from cereal grain crops like wheat, oats, rye, and barley. Benefits of straw as a grass seed cover include:
- Lightweight – Easy to spread manually or with a blower
- Moisture retention – Allows light and water to permeate while protecting seeds/soil
- Weed suppression – Physical barrier can prevent some weed growth
- Availability – Widely available and relatively inexpensive
There are a few downsides to straw. It can blow away in very windy conditions if not anchored down. Straw may also contain unwanted weed seeds that could germinate in your new lawn. Overall though, straw is an excellent choice for covering grass seed due to its combination of moisture retention, affordability, and availability.
Hydromulch
Hydromulch consists of wood fiber mulch blended with tackifiers and sometimes grass seed. It is sprayed over seeded areas as a liquid slurry that dries into a protective blanket. Benefits of hydromulch include:
- No blowing or drifting – Hydromulch forms a stable mat over seeds
- Contains seed – Seed can be incorporated into the hydromulch
- Erosion control – Effective at holding soil in place on slopes
- Weed barrier – Thicker barrier than straw
The main disadvantages of hydromulch are the upfront cost and availability. Renting and operating hydromulch equipment requires professional expertise. The material costs more than straw. However, in the right scenarios like steep slopes it can be the best option.
Compost
Screened compost can also be used to cover seeded areas. High-quality compost offers these advantages:
- Nutrients for seedlings – Compost releases nutrients that benefit new grass plants
- Water retention – Compost holds more moisture than straw or other covers
- Weed suppression – Dense compost smothers potential weeds
- Erosion control – Compost resists washing away better than straw
The two main limitations of compost are cost and availability. Purchasing, transporting, and spreading enough compost to cover a lawn can be expensive. Finding high-quality screened compost may also be difficult in some regions. But where available, compost is one of the best options for boosting the success of a new lawn.
Peat Moss
Peat moss is a common garden soil amendment that can also be used when seeding grass. Advantages of peat moss include:
- Lightweight – Easy to spread by hand or with a spreader
- Moisture retention
- Germination aid – Acidic pH beneficial for most grass species
- Readily available – Sold compressed in bags
Drawbacks of peat moss are cost, moisture issues, and sustainability concerns. Peat moss is more expensive per unit area than straw. It can repel water when very dry. Peat moss is also considered a nonrenewable resource, extracted from fragile wetland ecosystems.
Hay
Some people use hay as a grass seed cover, but hay is generally a poor choice. Hay is made of grasses like alfalfa, clover, and other forages. It has several disadvantages compared to straw:
- Seed content – Hay contains lots of seeds that will germinate in your lawn
- Moisture issues – Dense hay resists water penetration and drying
- Availability – Much less available than straw
- Cost – Typically more expensive than straw
While straw consists of dead cereal stalks, hay is full of living material that can complicate establishing a new lawn. The seeds can introduce weeds and inconsistency. Hay should be avoided as a grass seed cover in most situations.
Wood Fiber Blankets
Like hydromulch, specialized wood fiber blankets can also be used to cover seeded areas. These blankets offer excellent erosion control and moisture retention. But they are one of the more expensive covering options. Wood fiber blankets are best suited to areas highly prone to erosion that warrant the added cost.
Polymer-Coated Straw
Straw coated with polymers or latex offers benefits over regular straw. The polymers help the straw resist displacement by wind or water. Coated straw products can be worth the extra investment for lawn projects in windy regions or on slopes.
Geotextiles
Plastic or natural fiber geotextile blankets provide good protection from erosion. But geotextiles lack water holding capacity and are prone to displacement. They are not ideal for promoting germination and establishment of grass seed.
How Much Material is Needed?
A thin, 1/4 to 1/2 inch layer of material is sufficient when covering grass seed. Any more can inhibit growth. The seed just needs a little protection, not to be buried deeply. One bale of straw can cover up to 1000 sq ft of seeded area at this thickness.
Hydromulch is sprayed on at a rate of about 1,500-3,000 lb per acre. Compost is ideally applied 1/4 inch deep over the lawn, which works out to about 1-2 cubic yards per 1000 sq ft.
When to Apply Grass Seed Cover
The best time to spread covering material over newly seeded areas is immediately after completing the seeding. Covering the seed helps retain moisture and regulates soil temperature right from the start. This promotes faster, more consistent germination.
In fall plantings, temporary cover may be removed after about 2 months to allow sunlight to strengthen young plants before winter. Covers like compost or peat moss can be left in place indefinitely.
How to Apply Cover Material
Lightweight materials like straw and peat moss can be spread by hand using a pitchfork or rake. A leaf blower on low setting also works well to distribute straw evenly. For larger areas, a mechanized straw blower is highly recommended to make quick work of application.
Compost and other bulkier materials need to be dumped and spread with a shovel or loader. Hydromulch requires specialized spray equipment. Following manufacturer’s instructions for mixing and application is crucial for success.
The key is applying cover materials uniformly and at the proper thickness over all seeded areas. Uneven coverage can lead to patchy growth. It’s also important to not overload areas with cover resulting in excess thickness.
Anchoring the Cover
Covers like straw must be anchored in place until plants are established. Otherwise wind and rain will displace the straw, exposing areas of seed. There are a few techniques to anchor straw or other loose materials:
- Rolling – Compressing the straw by rolling the area with a water-filled roller. The straw remains compacted as it decomposes.
- Crimping – Dragging a mechanical crimper over the area to push straw partially into the soil.
- Tackifiers – Spraying liquid tackifiers like psyllium or guar gum over the top of straw chemically binds the fibers.
- Netting – Laying biodegradable netting over the straw physically holds it in place as plants grow.
Hydromulch, compost, and other heavy covers do not need additional anchoring. Their weight keeps them in place until plants emerge.
Remove Excess Cover Material
As grass plants grow, decompose cover material over time. Excessive amounts of lingering cover can be detrimental. Practices like raking up decomposed straw help prevent accumulation:
- Allow sunlight – Removes barrier that blocks light from young grass
- Reduce smothering – Minimizes chance of new plants being smothered
- Improve air flow – More airflow helps dry foliage, reducing disease risk
- Enhance appearance – Gets rid of unsightly decomposing layers on lawn surface
Generally, straw or other temporary seed covers that remain should be cleared once grass is around 2 inches tall. At this point, the plants are established and further cover is unneeded. Letting the decomposing cover persist can lead to issues.
Special Considerations for Slopes
Slopes and hillsides require special care when seeding and covering grass. The incline makes it difficult for seed, topsoil, and cover materials to resist washout. Here are some tips for seeding slopes:
- Plant at optimal time – Fall is better than spring for slopes to give plants time to establish before heavy rain
- Divert runoff – Use berms and channels above slopes to divert water flow around newly planted areas
- Use erosion control mats – Jute or coconut fiber mats prevent washout better than straw
- Anchor well – Sturdy netting or tacifiers are a must to hold cover in place on inclines
- Seed more heavily – Use 50% or more extra seed to account for some loss
Planting on slopes requires extra diligence. But using appropriate techniques and materials can still produce good results.
Monitoring Newly Seeded Lawns
Close monitoring in the weeks after seeding and covering is important to achieve lawn success. Be sure to check for and address issues like:
- Moisture levels – Supplement rainfall to keep top 1″ of soil consistently moist
- Displaced cover – Replace stray patches of cover material
- Weeds – Hand pull any weeds that germinate in seedbed before they spread
- Pests – Watch for evidence of bird or insect damage and treat accordingly
- Thin areas – Reseed small bare or sparse areas for uniform establishment
Taking steps to remedy problems as soon as they appear prevents setbacks in the growth of a new lawn.
Frequently Asked Questions
What are the signs my grass seed is germinating properly?
Within 5-10 days after planting, you should notice some of these signs that seeds are germinating beneath the cover:
- Visible seedlings – Sprouts begin peeking through cover
- Color change – Straw or other covers shift from tan to green tint
- Odor – Smell of growing grass
- Growth flush – Sudden increase in seedling density
If few or no sprouts are visible after 2-3 weeks, reseeding may be required in bare areas.
How long should seed covering remain before removal?
Here are general guidelines for removing temporary grass seed covers:
- Straw – Remove after 2 months or once grass is 2+ inches tall
- Hydromulch – Allow to decompose gradually on its own
- Compost – Can remain indefinitely without issue
- Peat moss – Remove after 1-2 months to prevent matting
Permanent covers like compost and hydromulch are fine to keep in place. But temporary covers should be cleared when no longer needed.
Is covering grass seed always necessary?
Covering newly seeded areas offers important benefits in most cases. But there are a few exceptions where seed cover may not be needed:
- Winter dormant seeding – Frozen ground provides natural cover
- Small patches – Hand raking soil over reseeded spots sufficient
- Frequent light irrigation – Can water newly seeded beds very frequently instead
- Grassed waterways – Seed washed into soil crevices and established without cover
But in general, using some type of cover remains the recommended practice to ensure successful grass seed germination and establishment.
Conclusion
Getting good seed-to-soil contact and covering planted grass seed properly leads to higher germination rates and better establishment. Materials like straw, hydromulch, compost, and peat moss all have benefits and drawbacks. Choose the right option for your situation based on climate, site factors, availability, and budget.
With the correct cover in place, maintaining adequate moisture and controlling weeds are the next keys to lawn success. But starting with effective seed coverage sets the foundation for getting a new lawn off to a great start!
