How Does Grass Spread, Flowers, Seeds, or Rhizome Runners?

When preparing to plant grass on your lawn, there are several things you need to keep in mind. 

One such thing is how best to lay the sod and how densely to scatter the grass seed. That’s because, while some grasses will soon spread and fill the bare spots on your lawn, others will not. Of course, you want a beautiful, thick lawn, like every other homeowner, and as such, you need your grass to spread out to remain evergreen and patchless.

In this article, we’ll be asking …just how does grass spread. Is it through flowering, seeds, or some other marvel of nature…?

How Does Grass Spread in My Yard?

Grass will always spread. However, some types spread out fast, while others may take years before filling the bare spots in your lawn. 

Some of the methods that different types of turfgrass use to spread include:

Flowering: Some grass species grow flowers upon reaching adulthood. The flowers then bear seeds that fall and develop into more grass after fertilization.

Bearing seeds: This involves sowing seeds in the bare spots on your lawn. The seeds then grow into the grass after a while. Some grass blades also seed by themselves, resulting in more grass to fill the spaces in your lawn. 

Rhizome runners: Rhizome-capable species of grass have their stems running underground. Shoots grow far away from the parent plant at points where a node develops in the rhizome. At that point, a root will grow downwards while a shoot grows upwards. Examples of such grass are Kentucky bluegrass and fine fescue. 

Stolons: These are horizontal stems that, unlike rhizomes, grow on top of the ground. New plants will grow at each node and will be no different from the mother plant genetically. Grasses that spread through stolons include Buffalo, creeping bentgrass, Zoysia grass, and St. Augustine grass.  

Tillering: Tillers are the offshoots that grow from the crown of the original grass. Most lawn grasses will produce tillers which in turn ensures they spread, widen, and thicken. Though tillering may take time before filling the bare spots, soon, your grass will get thicker. Most homeowners use this method to expand their yard. It’s known as either bunchgrass or clump grass. An example of bunchgrass is perennial ryegrass, and tall fescue is an example of clump grass. 

Rhizomes and stolons: Some grass species typically spread through a combination of rhizomes and stolons. Due to their aggressiveness, these grasses fill in the empty spaces very fast. Additionally, they tend to grow over other plant species. Zoysia and Bermuda grass are examples of grass that spread through this method. 

Does Grass Flower and Go to Seed?

Some types of grasses tend to grow flower clusters, which produce grass seeds. This flowering process is known as inflorescence. It happens when the grass reaches adulthood and has sufficient leaf blades.

As long as you don’t mow or cut your turfgrass, its stems lengthen and develop inflorescence. However, you should note that this can only happen under favorable climatic conditions with adequate water and sunlight.

While in some cases, grass flowers will have both reproductive systems in a single flower, it doesn’t always happen. Of importance is that the flowers will fertilize when pollen from compatible grasses falls on them, and the process of seed-bearing will begin.

Is it Okay to Let Grass Go to Seed?

If a grass species is the seeding type, it’ll soon start producing seeds. It doesn’t matter whether you’re constantly cutting and mowing or not. Mother nature intends them to produce grass seedlings, and that is what you’ll observe on top of grass blades.

Letting grass go to seed is one way of spreading grass in the empty spaces in your lawn. If you observe some seeds, don’t mow until the seeds mature. The seeds will mature, dry out, and fall. Then, they’ll germinate, giving life to new grass plants. You can even collect them and spread them as you wish.

Some grass types usually adopt as a result of frequent mowing. As such, they alter their biological functioning such that they’ll form seeds near the ground where the mower blades cannot cut. These are the same seeds that’ll accelerate the thickening of your lawn.

However, not all grasses will go to seed. Some will become hybrid due to constant intermingling with other species. These grasses are usually sterile, meaning they’ll never seed.

Grass Lifecycle

All plants have a lifecycle, and grass in your yard is no exception. Different types of grasses will have different lifecycles. Besides, your location will also affect these cycles.

If your lawn contains cool-season annual grass, be ready to plant new grass every year because its life cycle is no longer than that. Their cycle begins in the early fall and ends in the summer when it dies. It’s most suitable for farmers and not lawns.

For cool-season perennial grasses, they have four significant cycles every year. During winter, the grasses lie dormant, only for their growth to surge in the spring months. In the summer, the rate tapers off before going through the final cycle during fall. That’s when grass flourishes again before getting back to dormancy as the process starts all over.

Warm-season perennials will be highly active in the warm months and relax in the cooler ones. Under extremely high temperatures, some plants will slow down their growth rate and go dormant, especially where water is inadequate.  

Which Varieties of Grass Self Seed?

Most grass varieties will self-seed at different times of the year. Some of the grass varieties that usually self-seed, and especially cool-season grasses, include:

  • Perennial ryegrass
  • Kentucky bluegrass
  • Tall fescue
  • Zoysia grass

Can Grass Spread Through Roots?

Some lawns usually spread through their underground or above-the-ground roots. These are the rhizome and stolon grasses.

For stolons, runners will run across the yard, and when they come into contact with soil, roots will develop down, and a new plant will shoot up, filling the space. Warm-season grasses like centipede grass and St. Augustine are examples of grasses that spread through above-the-ground root systems.

Similarly, rhizomes spread their roots but under the soil. When the roots reach a point where sunlight and water are sufficient, they grow downwards, and a shoot will grow upwards. A new plant will fill the area. 

Kentucky Bluegrass is an example of a cooler-season grass that spreads through underground roots.

Which Varieties of Grasses Send Out Runners

 Two types of grasses send out runners. These are:

  • Rhizome grasses: These send out runners under the soil. Examples are Fine fescue and Kentucky bluegrass.
  • Stolon grasses: These send out runners above the ground. Examples are Buffalo, St. Augustine, and Zoysia grass.

Some grass varieties send out runners both under and over the soils. Thereupon, they spread through both rhizomes and stolons. An example is the Bermuda grass.

Will Grass Spread to Bare Spots in My Lawn?

Yes, grass will always spread. I have seen lawns getting thick within a few months, and others taking years before filling bare spaces. It all depends on the type of grass you have on your lawn. 

If your lawn grass is a rhizome or a stolon, you can expect the grass to spread quickly to fill the bare spots. However, grasses such as bunchgrass will take a bit more to spread out.

Does Cutting Grass Help it to Spread?

Without a doubt, cutting grass can help it spread. But some grasses will spread better with cutting than others. Generally, species that send out runners will quickly spread after mowing. These include stolon and rhizome varieties.

For the grass to spread after cutting, you need to mow in the right way. This entails:

  • Ensuring you cut the grass to approximately two inches. Don’t make it shorter than this because it won’t spread.
  • Watering and even fertilizing will accelerate the spreading.
  • Mowing in different directions.
  • Cutting the grass, observing the right timelines, but avoid doing it too often.

With these mowing techniques, your grass will keep spreading every time you cut.

Does Leaving Grass to Grow Long Help it Spread?

Long grass usually has enough leaf blades. The thick blades and long stems do not directly help spread the grass. Nevertheless, they tend to develop inflorescence. 

Especially if the prevailing climatic conditions are favorable, this long grass will grow flowers. After pollination and fertilization, seeds will form, mature, dry up, and fall. Then, they’ll germinate into new plants that fill the bald spaces.

Therefore, if your lawn contains self-seeding grass, allow it to grow long without mowing or cutting, and soon, new seeds will grow into the grass, helping cover any open spots.

How to Stop Lawn Spreading from Rhizomes

One feature I especially like about rhizome grass is how fast it spreads. That said, this can equally be problematic when it applies to areas you never wanted it to reach. 

Fortunately, you can control or stop your lawn from spreading to walkaways or other unwanted areas by installing lawn edges.

Lawn edges are available in a wide range of varieties. You can opt for metal or plastic edges. Alternatively, you can customize lawn edges yourself using brick or concrete. That way, you stop rhizome grass from spreading uncontrollably. 

It’s worth mentioning that for the edges to be effective, they need to reach six inches at a minimum below the ground.

Personally, I prefer mow-over lawn edging. I set it up into the ground, leaving it level with my lawn grass, and as I mow the edge of the yard, the mower gives me a clean cut. Metal edging is also effective and pretty durable.

A further way to stop lawn spreading through its rhizomes is by mowing the lawn regularly and keeping the blades of your lawnmower sharp.

How to Stop Grass Spreading from Self Seeding

Of course, grass aggressively self-seeds if you leave it unmowed. By not cutting it down, you encourage the blades and stems to mature, ultimately developing inflorescence. The flowers then fertilize and produce seeds which promote the spreading. 

Therefore, if you want no more spreading, keep on top of your mowing responsibilities and cut back the self-seeding grass varieties.

How Deep Should Lawn Edging Be to Stop Grass Spreading

Lawn edging is a way of preventing lawn grass from spreading to areas you never intended it. If not correctly installed, lawn edges may not be effective. 

Therefore, it’s best to ensure you install them at least six inches deep. In so doing, you help prevent the grass from spreading uncontrollably.

How Does Grass Spread: Takeaway

Most grasses will spread. But you can also play your part in ensuring they spread faster and better or in a controlled manner. As you have learned, you can water, fertilize, or even mow some varieties to encourage the spreading. 

What matters is that you understand the type of grass you have and how it spreads. Soon, all those bald spots will be fully covered, getting you a thick, green, and lush lawn.