Nut grass, also called nutsedge, is a very tough weed. It grows fast and can take over garden beds and lawns. Getting rid of it takes time and effort. This guide will show you how to handle this stubborn plant and help you fight it in your garden starting today.
Image Source: grasspad.com
What Nut Grass Is
Nut grass is not a true grass. It is a sedge. Sedges look like grass, but they have triangle-shaped stems. If you roll the stem between your fingers, you can feel the flat sides. True grasses have round or flat stems. Nut grass leaves are shiny and come out from the stem in sets of three. They grow faster than most lawn grasses.
Identifying nut grass is key. Look for these signs:
* Shiny, bright green leaves.
* Leaves growing in sets of three from the base.
* Triangle-shaped stems.
* It grows much faster than the plants around it, especially in hot weather.
Later in the season, it grows tall stalks with seed heads. These seed heads can be yellow or purple. Yellow nutsedge has light brown seed heads. Purple nutsedge has dark reddish-brown seed heads. Seeing the seed heads is a sure sign you have nutsedge. But the real problem is underground.
Why Nut Grass Is Hard To Kill
Many people ask, “Why is nut grass hard to kill?” The main reason is its rootsystem. Nut grass has rhizomes and tubers. Rhizomes are underground stems that grow sideways. New plants can sprout from these rhizomes. Tubers are small swellings on the rhizomes. People often call these “nuts.”
These tubers are like tiny potatoes. Each one can grow into a new plant. A single nut grass plant can make hundreds or even thousands of these tubers in one year. The tubers can stay alive in the soil for several years.
- Deep and Strong Roots: The roots grow deep. This makes pulling the plant hard. Often, the leaves break off, leaving the tubers behind.
- Many Tubers: The tubers store energy. If you pull the top part of the plant, the tubers have food to grow new shoots quickly.
- New Tubers Form Fast: The plant makes new tubers very quickly, especially when it is trying to survive after the top growth is cut or pulled.
- Resistant to Chemicals: Some weed killers that work on grass weeds do not work well on nut grass because it is a sedge.
Dealing with nutsedge means you must fight the parts you cannot see underground. You have to deal with the tubers. If you only remove the top leaves, the plant just sends up new shoots from the tubers. This is why simple pulling rarely works and can even make the problem worse by breaking up rhizomes and spreading tubers.
Best Time To Kill Nut Grass
Timing is very important when trying to get rid of nut grass. The best time to kill nut grass is when it is actively growing. This is usually in late spring and early summer. The plant is putting lots of energy into growing leaves and roots.
Why is this the best time?
* Energy Use: The plant is sending energy from the tubers up to the leaves to grow.
* Weed Killer Moves: If you use a weed killer, the plant will pull the chemical down into the roots and tubers. This is much more effective than spraying a plant that is not actively growing.
* Before Tubers Form: Killing the plant before it makes lots of new tubers stops the problem from getting bigger later in the season or next year. Nut grass starts making new tubers in mid-summer.
So, watch your garden in late spring. When you see the first shoots of nut grass appear, that is the time to start your fight. Keep treating it through early summer. Killing the plant repeatedly before it can store energy in new tubers weakens it over time.
Nut Grass Control Methods
There are several ways to control nut grass. No single method works instantly. You often need to use a mix of methods. These methods fall into different groups:
* Pulling or digging by hand.
* Covering the soil (smothering).
* Using natural or homemade sprays.
* Using chemical weed killers.
* Taking steps to stop it from spreading.
Let’s look at each of these Nut grass control methods in more detail.
Removing Nut Grass by Hand
This seems like the simplest way, but it must be done carefully. Pulling nut grass can be hard because the roots are strong and the tubers break off easily.
Here are tips for dealing with nutsedge by hand:
* Pull when soil is wet: Wet soil makes it easier to pull out more of the root system. The tubers are less likely to break off and stay in the ground. Water the area well before you start.
* Dig, don’t just pull: Use a small shovel or trowel. Dig around the plant. Try to lift the whole plant, including the roots and any attached tubers. This is better than just pulling the leaves.
* Check for tubers: Look closely at the roots you pull out. Are there small, hard lumps (the tubers)? Make sure you get as many of these as possible.
* Repeat often: You will not get all the tubers the first time. New shoots will come up from any tubers left behind. Pull or dig these new shoots as soon as you see them. Do this every few days.
* Dispose properly: Do not put nut grass plants with tubers in your compost pile. The tubers can live in compost and spread the weed when you use the compost. Put them in the trash.
Pulling or digging by hand is best for small areas or when you see just a few plants. It is very time-consuming and hard work for larger areas. It is also hard to be sure you got all the tubers.
Smothering Nut Grass
Smothering nut grass means covering the area so the plants cannot get sunlight. Without sunlight, the plant cannot make food and will die. This method can kill the tubers too if the cover is left in place long enough.
This is one way of Smothering nut grass:
* Use thick material: Black plastic sheeting or thick layers of cardboard work well. Do not use clear plastic; it can heat the soil and help the nut grass grow faster at first.
* Cover completely: Make sure the material covers the whole area where the nut grass is growing. Extend the cover past the edge of the nut grass patch by a few feet.
* Weigh it down: Use rocks, bricks, or soil to hold the edges of the material down tightly. No light should get to the plants. This also traps heat and moisture, which can help kill the tubers.
* Leave it in place: You need to leave the cover on for a long time, often a full growing season (several months). This starves the plants and uses up the energy in the tubers.
Smothering is a good method for areas that are not currently being used for growing plants. It is also an organic method. It takes patience because it is slow. When you remove the cover, check carefully for any new shoots and deal with them quickly.
Organic Nut Grass Killer Options
Many gardeners want to avoid harsh chemicals. There are organic ways to fight nut grass. While not always as fast as chemicals, these methods can be effective over time. Using an Organic nut grass killer means using natural substances or methods.
- Corn Gluten Meal: This is often sold as a weed preventer. It can help stop weed seeds from sprouting. However, nut grass grows from tubers, not just seeds. Corn gluten meal may not work well on existing nut grass. Some studies show it might slow growth, but it is not a strong killer for nutsedge tubers.
- Horticultural Vinegar: Strong vinegar (20% acetic acid or higher, not kitchen vinegar) can burn the leaves of nut grass. This kills the top growth. However, like pulling, it often does not kill the tubers underground. The plant will regrow. You must spray new growth repeatedly as it appears. Be careful, strong vinegar can hurt other plants and soil.
- Boiling Water: Pouring boiling water on nut grass can kill the plant it touches. Again, this mostly affects the top growth and might not kill deep tubers. It also kills any other plant or helpful tiny life in the soil where you pour it. Use carefully and only in small spots away from plants you want to keep.
- Specialized Organic Herbicides: Some companies make organic weed killers that are supposed to work on nutsedge. These often contain things like plant oils (like clove oil) or fatty acids. They work by breaking down the plant’s outer layer, causing it to dry out and die. Like vinegar, they are mostly contact killers, meaning they kill what they touch. They often do not move down into the tubers. You will need to spray new growth many times. Always read the label carefully to make sure it is safe for your use and says it works on nutsedge.
These organic methods require repeated effort. They focus on killing the top growth, trying to starve the tubers over time. You have to be persistent.
Homemade Nut Grass Killer Ideas
Many people look for a Homemade nut grass killer using common household items. Some ideas you might hear about include:
* Vinegar, Salt, and Dish Soap Mix: A common recipe is mixing white vinegar, salt, and a little dish soap. The vinegar burns the leaves. The salt is supposed to dry out and kill the plant, but too much salt can seriously harm your soil for a long time, making it hard to grow anything. The soap helps the mix stick to the leaves.
* Rubbing Alcohol: Some people suggest spraying rubbing alcohol. This can dry out leaves, but it’s unlikely to move down to the tubers.
* Bleach: Do not use bleach in your garden. Bleach is very harmful to soil life, plants, and water. It does not kill tubers and causes more harm than good.
Most homemade weed killers, especially those using vinegar or salt, only kill the leaves they touch. They do not travel down to the tubers effectively. Using salt can ruin your soil. While a simple vinegar spray (without salt) might burn back top growth, it acts like the horticultural vinegar mentioned earlier – requiring repeated application to try and weaken the plant over a long time.
If you try a Homemade nut grass killer, be very careful about what you mix. Avoid salt. Understand that these are usually contact killers only and will not solve the deep-rooted tuber problem on their own. They work best as part of a bigger plan, maybe combined with digging or smothering, focusing on hitting the plant every time new leaves appear.
Chemical Nutsedge Control
Using chemical weed killers is often the fastest way to reduce a large problem with nut grass. However, you must choose the right chemical. Many common lawn weed killers do not work on nut grass because it is a sedge. You need a product made for nutsedge.
Look for weed killers that list nutsedge (or nut grass) on the label. The active ingredient is often something like:
* Halosulfuron-methyl (often sold under brand names like SedgeHammer or Blade)
* Sulfentrazone (often in products like Dismiss)
* Imazosulfuron
* Bentazon (often sold as Basagran)
These chemicals are designed to be taken up by the plant’s leaves and moved down to the tubers. This kills the whole plant, including the underground parts. This is the most effective way to achieve Chemical nutsedge control.
Here are important tips for using chemical killers:
* Read the Label: Always read the product label completely before buying and using any chemical. The label tells you:
* If it works on nutsedge.
* How much to use.
* When to apply it (usually when nut grass is actively growing).
* Where you can use it (in lawns, garden beds, around specific plants).
* How to apply it safely.
* How long to wait before planting in the area.
* Timing is Key: As mentioned before, apply when nut grass is actively growing (late spring/early summer is best). The plant needs to be healthy enough to pull the chemical down to the roots.
* Follow Instructions Exactly: Using too little won’t work. Using too much can harm your other plants or the soil. Mix and apply exactly as directed.
* Target the Weed: Try to spray only the nut grass to protect your other plants.
* Repeat Application: You will likely need to spray more than once. New nut grass shoots will come up from tubers that were not killed by the first spray, or from tubers that were too deep. The label will tell you how long to wait between sprays.
* Be Patient: Even with chemicals, it can take a week or two to see the nut grass start to die. The leaves will turn yellow or brown.
* Safety: Wear gloves and other protective gear listed on the label. Keep pets and people away from the treated area until it is dry.
Chemical control can be very effective for large problems, but it requires careful use. Make sure the product is safe to use in your specific garden area (e.g., vegetable garden vs. lawn).
Preventing Nut Grass Spread
The best way to deal with nut grass is to stop it from starting or spreading in the first place. Preventing nut grass spread is an important part of long-term control.
- Check new plants and soil: Nut grass tubers can come into your garden on the roots of new plants you buy, or in soil or mulch that is not clean. Inspect anything you bring into your garden. Get soil and mulch from reputable sources.
- Clean your tools: If you dig in an area with nut grass, soil can stick to your shovel, trowel, or tiller. This soil might have tubers in it. Clean your tools well before using them in a clean part of the garden.
- Avoid tilling infected areas: Tilling or digging in a patch of nut grass seems like a good idea, but it can actually chop up the rhizomes and tubers and spread them all over the garden. Each piece can grow into a new plant. This makes the problem much worse. It’s better to treat the area before or after digging, or use smothering.
- Keep your plants healthy: A thick, healthy lawn or garden bed makes it harder for weeds like nut grass to get started. They cannot compete for light, water, and nutrients. Water correctly, feed your plants, and mow your lawn at the right height (usually higher is better for lawns to shade out weeds).
- Mulch garden beds: Use a thick layer of mulch (2-3 inches) in garden beds. This blocks light and makes it harder for nut grass shoots to push through.
By taking these steps, you can greatly reduce the chance of nut grass taking over your garden.
Compressing the Problem: Targeting Nut Grass Effectively
Dealing with nutsedge successfully means you need a plan. Simply pulling the leaves will not work. You must attack the plant’s ability to regrow from its tubers. This takes repeated action.
Think of it like this: each nut grass plant is a factory making more tubers. Your goal is to shut down the factory.
- Find it early: Spot nut grass as soon as it comes up in late spring/early summer. The younger the plant, the less energy stored in tubers and the fewer tubers it has made.
- Choose your weapon: Decide if you will dig, smother, use organic sprays, or use chemical sprays. Your choice might depend on how much nut grass you have, where it is located, and your comfort with chemicals.
- Attack the tubers:
- If digging, try to get the whole plant, roots, and tubers out.
- If smothering, cover the area for a long time to starve the tubers.
- If spraying (organic or chemical), apply when the plant is actively growing so the treatment moves down to the tubers.
- Repeat, Repeat, Repeat: This is the most important step. New shoots will appear. You must deal with them right away.
- Pull or dig new shoots.
- Respray new shoots as allowed by the product label.
- Do not let new leaves grow for long, because they will start making new tubers.
Consistency is key. Do not let the nut grass leaves grow large or produce seed heads. Each time you remove the top growth, the plant uses energy from its tubers to regrow. If you keep removing the top growth, the plant runs out of stored energy in the tubers and eventually dies. This process can take several months or even a couple of years for a bad problem.
Comparing Nut Grass Control Methods
Here is a simple table looking at the different methods:
| Method | How it Works | Pros | Cons | Best For |
|---|---|---|---|---|
| Hand Pulling/Digging | Removes the plant and hopefully tubers | No chemicals, good for small spots | Hard work, often leaves tubers, must be repeated | Small patches, wet soil |
| Smothering (Covering) | Blocks sunlight, starves plant and tubers | No chemicals, kills roots over time | Very slow (months), area unusable while covered | Areas not needed for planting right now |
| Organic Sprays | Burns top leaves (contact kill) | Natural ingredients | Often doesn’t kill tubers, needs many sprays, can harm other plants | Minor problems, trying non-chemical approach |
| Homemade Sprays | Burns top leaves (contact kill) | Uses household items | Often doesn’t kill tubers, salt can ruin soil, not well tested | Quick fix for tiny spots, use caution |
| Chemical Weed Killers | Moves through plant to kill tubers | Can kill tubers, effective for large areas | Uses chemicals, must choose right product, can harm other plants if misapplied | Larger problems, faster results |
Remember, combining methods can be very powerful. For example, you could dig up a small patch, then cover the area with mulch to prevent regrowth. Or use a chemical spray on a large area, then pull any new shoots that appear later.
Specific Challenges: Nut Grass in Lawns vs. Garden Beds
Dealing with nutsedge can be different depending on where it is growing.
- In Lawns: You need a control method that kills the nut grass but does not kill your lawn grass. This is where specific chemical nutsedge control products are often used. Products containing halosulfuron-methyl or sulfentrazone are usually safe for established lawns, but always check the label for your specific grass type. Pulling is hard in lawns without damaging the grass, and smothering would kill the lawn grass too. Keeping the lawn thick and healthy is a key way of Preventing nut grass spread here.
- In Garden Beds: You have more options. You can dig carefully around your desired plants. Smothering a whole bed is possible before planting or after harvest. Organic or Homemade nut grass killer sprays can be used, but be very careful not to spray your garden plants. Chemical options made for garden beds can also be used, but check the label to make sure they are safe for use around the plants you want to keep, or if there is a waiting period before you can plant after spraying. Mulching is an excellent way to suppress nut grass in garden beds.
Long-Term Strategy for Dealing with Nutsedge
Getting rid of nut grass is rarely a one-time fix. It is a long-term battle.
* Be Patient: It takes time to use up the energy in the tubers.
* Be Watchful: Keep an eye out for new nut grass shoots, especially in warm weather.
* Act Quickly: Deal with new growth as soon as you see it, before it can make new tubers.
* Improve Soil Health: Healthy soil and healthy plants resist weeds better.
* Prevent New Infestations: Check new materials and clean tools.
If you are consistent, you can greatly reduce the amount of nut grass in your garden over time. You might never get rid of every single tuber, but you can keep the weed under control so it does not harm your garden plants or lawn. Dealing with nutsedge is a process of tiring out the plant and stopping it from making more tubers.
Frequently Asked Questions About Nut Grass
Q: Can nut grass die in winter?
A: The top part of nut grass (the leaves and stem) dies back in the winter in cold climates. However, the tubers underground survive the cold. They will sprout again when the weather warms up in spring.
Q: Will just mowing nut grass kill it?
A: No, mowing actually encourages nut grass. It removes the top growth, but the plant quickly sends up new leaves from the tubers. Mowing repeatedly without other control methods will not get rid of it. It can even help it spread by carrying small tubers on the mower.
Q: How long do nut grass tubers live in the soil?
A: Nut grass tubers are very tough. They can stay alive and able to sprout in the soil for several years, sometimes up to 10 years, waiting for the right conditions. This is why repeated treatment is so important.
Q: Is nut grass good for anything?
A: In some parts of the world, the tubers (nuts) are eaten. They are called chufa or tiger nuts. They have a sweet, nutty taste. However, in a garden setting, their aggressive growth makes them a harmful weed.
Q: What should I do with soil that has nut grass in it?
A: If you remove soil with nut grass tubers, do not spread it around your garden. Do not put it in your compost. Bag it and send it to the trash. If you have a large amount of soil that is heavily infested, you might need to solarize it (cover with clear plastic in hot sun for many weeks) or dispose of it carefully.
Getting rid of nut grass takes time and effort. But by using the right methods and being persistent, you can gain control over this tough weed in your garden. Start today by identifying the problem and choosing your first step towards control.