The grand illusion of a lawn being a simple thing to grow and enjoy has caused the earnest yard enthusiast nothing but trouble creating an unreal ideal of the ease of getting green grass.
A green lawn takes work, routine, and the proper additives and tools, but that doesn’t mean it has to be overly expensive or complicated. Instead, understanding how your lawn likes to grow can help make even tossing grass seed on top of soil effective.
Key Points:
- Grass seed can grow on top of soil, but germination rates will be lower, and it is more difficult to keep the soil moist.
- Properly prepping the soil and covering grass seed is critical for a better chance of successful germination.
- Without protective coverage, grass seeds can dry out, and roots lack the soil contact needed to successfully grow a dense lawn.
A beautiful lawn is not out of reach, but there can be negative effects to improper planting and not preparing your soil for seed.
In this article, we will look at what happens if grass seed is just thrown willy nilly on the surface of the soil and if there are better tried and true alternatives that will give you a consistently lush lawn regardless of your native soil type.
Can I Toss Grass Seed on My Lawn and Expect New Growth?
Normally germination rates for seeds range from 80 to 99% depending on the quality of the brand, storage, and shipping conditions, as well as a few other factors; just tossing seeds on top of the soil will not achieve these high rates and will yield far fewer grass blades than properly planted seeds.
In conditions of overseeding or adding grass seed to sparse areas, this can be reasonable, but if trying to start a lawn, these low germination rates will cause expensive problems and be a waste of time.
If you toss grass seed directly on top of the soil, not only will you have poor germination due to many seeds drying up or not staying moist enough to open, but you also expose your sees to wildlife like birds, rodents, and insects that will carry away seeds for a delicious meal.
If you will be growing a lawn from seed, make sure to cover the seeds with a layer of soil.
Can Grass Seed Grow above the Soil?
Grass seeds can germinate and grow on top of a layer of topsoil, but for fast root growth and more reliable sprouting, you will want to rake a bit of soil over newly sown seeds.
It is hard to keep the soil moist when the grass seed is on top as the wind and other environmental conditions will be constant; this is especially true of clay soil which may not absorb the water and could allow the seeds to run off with too much irrigation.
Moist soil is needed for seeds to germinate and may involve watering up to 3 times a day during the first 10 to 20 days after sowing. If your current soil is not ready for grass seed, it should be prepared to speed up the germination time and improve the success of germination greatly.
If you will grow grass seed above the soil, you must have the right form of soil underneath, and you need prepared soil for a sure germination process.
What Happens to Uncovered Grass Seed?
Uncovered grass seed is not a great way to try and start a healthy lawn.
Grass seeders should be used for even coverage and dense seed spreading, but all professional gardeners know that uncovered grass seed is not the simple answer to the problem of growing a new lawn. Beautiful dark-green lawns need better treatment than tossing uncovered grass seed and hoping for the best.
Dries Out
Grass seed needs to stay pretty moist in a humidity zone of around 80% to germinate and create a strong seedling. Even if you are planting a drought-tolerant grass type while it is a seed and newly growing, you will need to give it exactly what it needs to thrive.
Without a protective blanket of an inch of soil coverage, it will be hard to keep the seed from drying out. If you keep the soil moist above and below the seed, then it should germinate easily.
Weak Roots
Direct soil contact is needed to help the small roots immediately gain a grip on the soil. If the soil surface is obstructed with grass clippings or other lawn debris, roots may not be able to reach the nutrient-dense soil and achieve successful germination and growth.
Without the initial vigorous growth of roots, it will be hard for the grass to have any water retention, and the weak roots will die.
No Access to Nutrients
Most of the dense nutrients and beneficial soil microbes that grass needs to thrive live in the first few inches of soil.
If you sandwich the seeds between a top layer of earth and use proper soil preparation, the seeds will have everything they need to grow if the top is exposed to the elements, the same growing conditions will not be achieved, and a weaker grass will emerge.
Changing Conditions
The change in the daytime and nighttime weather conditions will not bother mature grass, but germinating seeds need a more constant environment.
In the soil, they will stay at a more constant temperature regardless of whether it is morning on evening above. Seeds that are exposed to the wind and sun will be less likely to germinate than ones blanketed in the protective womb of the earth.
Seed Eaters
No matter how well protected your lawn is, natural systems will have pests, and some of these intruders will want to take your grass seed. Creatures like ants and other seed-loving insects, birds, and rodents will all swoop, scurry, or crawl onto your lawn and eat your grass seeds.
You can make this harder to do by burying the seeds under a layer of dirt.
Although it is not a failsafe method, as all of these critters can move a small amount of earth quickly, the hidden seeds will be less conspicuous and, therefore, less likely to be tampered with, giving them a chance to germinate.
Grass Seeding Techniques
If you want to get the most out of your efforts and ensure your grass seed grows into a healthy lawn, you will want to prepare the soil before planting.
There are also a few things to keep in mind while the seeds are germinating and even after the new grass has emerged if you want the best results.
Below are some steps you can take to properly prepare your soil for new grass seed.
Technique | Method | Purpose |
Dethatch | Use a rake or power broom to remove all build-up of thatch and decomposing lawn debris that prevent direct contact with the soil | Removing thatch gives grass seeds the best chance of landing directly on the soil where they can grow strong roots and have access to all the life-giving functions residing within; removing debris also improves the soil’s ability to heat up in the sun and retain moisture both necessary functions for seed germination |
Aerate Soil | A core aerator or other lawn perforating method can be used to de-compact soil and give seeds spaces to safely fall into | Aeration increases the oxygen content in soil and improves root growth while ensuring full saturation during irrigation and giving beneficial aerobic bacteria what they need to propagate and provide nutrients to plant roots |
Special Soil for Seeds | Place soil designed for new grass seed in a thin layer across your lawn to even out low spots and create an ideal germination bed for grass seed | A soil that is formulated to have nutrients seedlings need can improve the chances that your grass gets what it needs to grow right away |
Water Deeply | Adjust your irrigation settings to give your lawn a deep frequent watering until the soil is damp but not soggy, and then reduce the watering amount to a light, frequent watering in preparation for planting | Fully saturating the soil gives your seeds plenty of moisture to germinate in and can be more forgiving than parched soil when irrigation is not forthcoming |
Sow Seeds Evenly | Even coverage will help all seeds grow into strong blades of grass and prevent clumps of competing turf and bare areas where no seeds landed | If you seed heavily in one area, you will likely be light in others, and your lawn will grow sparse and sickly from bare spots and overcrowding, allowing weeds and other invasive plants to make their way into your lawn |
Cover with Top Soil | Covering your seeds with a layer of topsoil or mature compost will give you seeds protection if it is a thin, even application; avoid piling soil on the seeds and make sure to rake everything into a thin layer to give your seeds more consistent growth | Without topsoil, seeds will die or germinate slowly covering can keep away pests and lock in moisture giving your seeds everything they need to grow into healthy turf |
Keep Moist | Let your irrigation system water the grass seed between 1 and 3 times a day as needed to ensure the soil never drys out | If the soil dries out, new roots can wither, and progress can be slowed or stunted, while a moist environment ensures continuous growth and strong root development |
Amend | Add a fertilizer designed to help new grass flourish and apply it per package instructions to your yard evenly and at the right time of day | Adding fertilizer can help your grass seed outcompete weed seeds and other competitors and will ensure there aren’t nutrient deficiencies when the grass reaches its active growth phases allowing for fast greening and mature turf in just a few months. |
Is it Better to Prepare Soil Before Sowing Grass Seed or After?
It is better to prepare the soil before and amend it after to prevent disturbing the recently sowed seeds and to avoid introducing weed seeds or other intruders that can inadvertently compete with your newly sprouting grass seed.
If you plant your grass seed, then try to aerate, dethatch, or even heavily fertilize, you could stunt or kill the seeds and seedlings that have started to grow.
If you will do anything to your lawn after you plant the grass seed, it should be just to add amendments like mature compost or seed-starting fertilizer to improve root development and germination rates in your lawn.