Peat moss or straw for grass seed is a tough call to make when germinating new seeds for overseeding or reseeding. Both materials are widely used in lawns across the US for covering new seeds and protecting them from desiccation and bird attacks.

Peat Moss or Straw

Let us see which one has more pros than cons in this compact guide. You can make a better, more informed decision after reading this extensive comparison guide.

Features Peat Moss Straw
Material Used Decomposing plant matter in an acidic bog Stalks of grains and stalks that have been dried thoroughly
Ability To Hold Water As much as 97 percent Around 20 percent
Seed Germination Rate Very high lower
longevity More than two years Less than a year
pH Of The Material Acidic

3.0 to 4.5


8.4 to 9.5

Price  Very expensive Very cheap

What Are The Differences Between Peat Moss and Straw For Grass Seed?

Peat for covering seeds is more expensive than straw but provides better moisture retention and is sterile. Whereas straw for grass seed cover is inexpensive, and prevents soil erosion, but may cause weeds to spread in the lawn. The peat moss is great for vegetation, as the straw for warmth. 

Peat moss is naturally the more expensive option as it is a nonrenewable resource. It is made from the partial decay of plant matter in the marshes’ oxygen-deprived and acidic environment. Moss is difficult to procure, process, and transport to other places, so it naturally costs more. Straw is much cheaper and easily available, even if it is of a higher quality.

Important Specs Regarding Peat Moss

The important specs for peat moss are that it is durable, in addition to being safe and sterile, it is used for vegetation because it helps in water retention. Although it may get blow easily, but it pushes the acidity out of the soil. 

Peat moss is sold after being sterilized and has a 97 percent water-holding capacity. However, it is a very expensive nonrenewable resource and not good for the planet in the long term.

– Durability

Peat moss is an effective soil amendment known for being long-lasting. It takes about two years to disintegrate completely when added to the soil in the right amounts. Throughout this period, it keeps providing the soil with nutrition, water retention, and improved aeration. 

Peat Moss Characteristics

– Safe And Sterile

The good thing about moss is that once it is collected from the marshes, it is usually sterilized by the packaging companies before selling for use. This makes it extremely secure to be used in the lawn and pots for growing grass and plants. This is also one of the many reasons this material is so expensive, but remember that it is durable and gives the best results.

You can feel safe that all fungal and bacterial spores and weed seeds have been killed and will not contaminate your lawn. We cannot emphasize how important this is as we have seen lush lawns being destroyed within weeks due to contaminated soil amendments. 

– Vegetation Uses

While you can use peat moss to cover the seeds in the lawn after sowing them, they have properties and use in lawn care. Moss is a great option which is best suited for flower beds, vegetable gardens, pots, and baskets. 

This is because they are rich in nutrients as they break down over time in the soil, and remember that vegetation need this in order to produce their best outcome. It also helps retain water and prevents the soil from drying, which is important when growing flowering plants and vegetables.

– Helps With Water Retention

When covering grass seeds or the grass itself with moss, the water-retentive properties of this material are really useful. It has a sponge-like ability to hold water as much as 20 times its weight. When sowing fresh seeds on a lawn, the seeds mustn’t be allowed to dry at all during the initial growth period.

Helps With Water Retention

When you don’t use moss during seeding for the first two weeks, you end up watering them up to five to six times a day. There is also very little risk of root rot or fungal attacks with moss because it has been sterilized properly, if you consider this aspect, it is such a great benefit, because these risks need proper management afterward, which would tire you.

As more time passes, you can start giving the seeds water less often, and the moss’ moisture retentive ability will adjust accordingly.

– Gets Blown Away Easily

The dry form in which moss is usually stored and transported is very fluffy and lightweight. This is useful during sales and transport as you can purchase a significantly large quantity of moss easily. On the flip side, dry moss tends to be so light and flimsy that it gets easily blown away by the wind and foot traffic, it will not establish or ground itself more, on the contrary, it will become easy to move. 

Over seeds, you will have to keep the moss layer moist all the time to keep it in place. The risk with moss blowing away is that it will take the seeds along with it and ruin their germination. This problem with moss flying away and the consequent soil erosion is more pronounced when the ground is uneven. 

– Eventually Pushes Out The Acidic Soil

Peat moss is acidic as it is obtained from the oxygen-deprived environment of the boggy marshes. When it is used to cover grass seeds as a top dressing and moistened with water, it leaches its acidity back into the soil. Over multiple seed germination processes, moss can permanently alter the pH of your lawn soil and make it unsuitable for grass growth. 

It has been discovered that a layer of moss that is even one-quarter of an inch thick can alter the soil pH by 0.5. This drop in pH is tolerated well by plants but not by most grass varieties that thrive under a pH range of 6.5 to 7.0. Which is, again, great for a choice of vegetables or plants, according to this range, you should choose the crops you are going to harvest and cover with it. 

Don’t worry about the germinating seedlings, as they grow well under a moss-top dressing during a season or two. We suggest alternating different top dressings during each reseeding or even through the process of over seeding period to prevent the long-term acidification of the soil by moss. 

Remember that if you have been using moss over seeds for several years now, you will see a marked decrease in the rate of germination as well as in the overall quality of the grass being produced. Always conduct soil testing to see if the pH is deranged and then correct it before proceeding with seeding. 

– Easy Ensemble

Once you have weighed all the pros and cons of peat as the top dressing for covering seeds as they germinate, it is time to order a pack of high-quality moss, remember that it is very easy and quick to ensemble this on your soil, as the results will be great too. 

First, the moss you purchase must be of the best quality and sterile. Mostly, it is a given that moss will be sterile, but it doesn’t hurt to check this with the manufacturer before placing your order. Tell the manufacturer about the size of your lawn, and they will send you the appropriate amount of peat needed for it.

Mow the grass in the soil down to a height of only two inches to help set the seeds better. Use a spreader instead of your hands to sow the seeds, as it does a more uniform job. You need not bury the seeds very deep, so rake over them gently.

Cover the seeds with a layer of peat between one-eighth to one-quarter of an inch thick with the help of a peat moss spreader. Water this peat topsoil right after spreading it in an even layer over the seeds. 

Important Specs Regarding Straw 

The important specs regarding straw is that it can be used as fertilizer, and won’t cause any soil compaction. A great benefit that it has is how it will prevent disturbance from birds, in addition, it keeps the soil moist. Although, it may spread weeds and is challenging to ensemble.

Straw is an inexpensive alternative to moss for laying over grass seeds and in lawn care. It does not cause soil compaction; instead, it keeps the birds from picking on seeds.

– Used As Fertilizer

A straw is just a collection of cereal stalks that have been dried thoroughly. It has no water retention or soil drainage properties but is rich in nitrogen and potassium and can be used as a fertilizer. Unfortunately, it breaks down rapidly in the soil and barely lasts for one whole year.

Straw Characteristics

– Won’t Cause Soil Compaction

The good thing about using straw over the soil is that it does not cause soil compaction because it is lightweight. As it decomposes into the soil over time, it becomes the organic loamy part of its constituents.

Being slightly alkaline, it also tends to maintain the right pH in which grass grows which shows that the soil will not fluctuate or rise when you have placed this the right way. To elaborate specifically, if you consider the loamy part of the soil is extremely water retentive and provides next-level aeration in it.

Keeping all these reasons in mind, there is no need to worry about the long-term consequences of using a straw.

– Prevents Disturbance By Birds

Seeds need not be covered by anything and will germinate exposed just fine. The only risk is that birds might get picked at by birds, blown away by the wind, or crushed under the feet of people accidentally walking over them. Laying a layer of straw is a protective measure against all three potential problems, and as a result, whatever you have planted will grow and thrive. 

– Keeping Soil Warm

Straw has little nutritional value and is best suited for keeping the soil warm while it covers it in a thick layer. Covering the soil with a thick layer of straw during winter helps prevent it from freezing, and forming any kind of frost on top of the plants.

Keeping Soil Warm

In addition to this, when you have placed it, it would also prevent soil erosion, so use it for lawns that face a lot of foot traffic.

– Might End Up Spreading Weeds

Although straw mulch and topsoil can be sterilized to get rid of microbes and weed seeds, they are usually sold as it is without being sterilized. When this straw is used to cover the newly laid down seeds and then moistened, there is always a risk that you will end up germinating the weed seeds as well.

Remember that grain weeds are typically more aggressive and will rapidly take root in your soil. Your average lawn grass will not be able to compete with these weeds and will soon be wiped out.

The alternative is to spend a lot of time and energy carrying out extensive weed pulling, this shows that useless shoots will stop, and will let your crops or plants grow in a liberal way, without blocking its freedom of growth. 

– More Challenging Ensemble

Grass seed germinates much faster when covered with a material that protects and nourishes it. When using pine straw or any other type of straw for this purpose, it is best to ask your supplier for sterilized ones, in order to be keen on the use. The reason why this is a great choice, is because it is a great way to minimize the risk of weed spreading that comes with this material, which is a bit challenging, but less than other ways.

Carry out all the prerequisites of sowing seeds in the soil, like aerating it with core aeration and mowing the grass at two inches. Always use a spreader to spread the seeds evenly on the lawn in straight lines. Once this is complete, you need to use a rake very lightly so that the seeds come in contact with the soil.

As the next step, take a stray and spread it over the sowed seeds in a layer that is not so thick that it blocks all light out. Keep in mind that seeds germinate only when they have unimpeded access to sunlight and air during their growth period. Remember that you must water the lawn thoroughly so the straw and the soil get properly hydrated.

Once the seeds germinate and the grass becomes tall enough to receive mowing, you need to remove the straw. Alternatively, you can mix it with a layer of compost over the soil as a rich source of nutrients, which would also be useful and beneficial for your crops in a great manner.


Both peat moss and straw are used as a thin protective covering over freshly sowed grass seeds in gardening. These have advantages and disadvantages, which we have discussed in detail above.

If you ask us for our recommendation, go for sterilized straw because it does the job without long-term risks like soil acidification. It is much less expensive and easily procured from any nearby farm.

5/5 - (5 votes)