Using cardboard to control allotment weeds

How long does it take for cardboard to decompose in soil

Answered By: David Richardson Date: created: Feb 06 2022

three monthsIn more typical garden conditions — when a piece of cardboard is used as mulch or specifically shredded and soaked to decompose efficiently — biodegradation occurs quickly, with the majority of cardboard completely broken down within three months..

Asked By: Tyler Watson Date: created: Feb 16 2021


Kill weeds on hard surfaces

Prevention is the best cure on hard surfaces, once the weed have breached your concrete or chips it can be almost impossible to rid yourself of them permanently.

Use two layers of weed control fabric before laying a new driveway or path.

Leave them too long and weeds will damage your concrete and quickly spread. 

Easier still would have been to place black landscape fabric and build a garden above the grass

Below you can see the weeds in our greenhouse when we moved to our new acreage. They were over 5 feet tall but because they hadn’t been watered in months they pulled out easier than I thought they would.

Sometimes using your hands to pull out weeds then hoeing is the best option. We were going to let the chickens in there for a few months but it was heading into winter and we didn’t have our flock yet.

After allowing the weeds to germinate and pulling them up again I decided to mulch to reduce any further weeds from coming up. 

What works better than landscape fabric

Answered By: Jordan Henderson Date: created: Apr 16 2021

Here are five easy and affordable alternatives to landscape fabric.Cardboard.Newspaper.Burlap.Ground cover plants.Herbicides.Oct 21, 2020

Asked By: Herbert Russell Date: created: Feb 10 2022

How thick does black plastic sheeting kill weeds

Answered By: Cyrus Powell Date: created: Sep 22 2021

Preparing the Plot Till or otherwise smooth out the soil on slight slopes so there are no lumpy areas. Measure the space, and then purchase clear plastic sheeting 2 to 4 mils thick from a hardware or construction supply store. The sheeting should be at least 6 inches longer in all dimensions than the garden space.

Asked By: Clifford Miller Date: created: Oct 01 2021

How To Use Cardboard As A Weed Barrier

Follow these simple steps to stop bothersome weeds from growing in your planter beds or garden.

Step 1 – Prep The Area

Prune any plant branches or stems in the area you plan to use the cardboard and rake away any thick piles of leaves or debris. 

Trim down long weeds or grasses as short as possible and remove any rocks so that the cardboard will lay flat on the soil. 

Measure out the area and select pieces of cardboard that will fully cover the space where you want to prevent weed growth.

Step 2 – Prep The Cardboard

Go over all the cardboard and remove all tape, staples, or strapping. 

Avoid using boxes that have a lot of ink printing since these chemicals will eventually leach into the soil and pose a problem to your plants’ health.

Use a utility knife to cut boxes along the seams into flat sections — cut pieces to fit the size of the area you are covering.

Step 3 – Lay The Cardboard

Begin on one end and start laying your cardboard over the surface of the soil. Make sure you overlap each piece by several inches to keep weeds from growing between cracks.

Use a utility knife to cut openings around the stems or trunks of plants and trees, making sure you leave around two to three inches of space around the base, so water and air can penetrate the soil.

If you want a longer-lasting weed barrier, go over the entire area with a second layer of cardboard.

Step 4 – Secure The Cardboard

You can use a hammer to pound in garden staples or stakes to keep the cardboard exactly where you want it. 

Using stakes is a great way to kill off areas of grass with cardboard, then be able to remove them when you’re ready to repurpose the space.

You can layer on wood mulch or gravel to keep the cardboard in place. Gravel or rocks will hold the cardboard in place, even during high winds, as long as you secure the edges down.

Wood mulch requires about four inches to weigh down the cardboard. A thin layer quickly moves after a rainstorm or in heavy winds, exposing the cardboard underneath, which can look shabby.

You can also layer soil and new plants over the cardboard.

In some areas, many people choose to lay down two or more layers of cardboard and then top it with more soil and plants.

This method is also perfect for creating a surface barrier when you install raised planter beds since it allows you to quickly fill the bed without the need to remove any weeds or grass underneath.

Step 5 – Maintain The Area

From my experience, it’s best to wet the entire area after you lay down mulch or rocks.

The water softens up the cardboard and allows everything to settle into place, which helps keep the material secure and deters animals from digging.

Keep an eye on the area and reapply the cardboard barrier when you notice new weed growth as the cardboard deteriorates.

I find that I need to redo my weed barriers about every two years, which is about the same time I need to refresh my wood mulch anyway.

WARNING: Termites will feed on cardboard just as they do on wood or other cellulose products. If termites are a concern, make sure you don’t use cardboard or wood mulch as a weed barrier around the perimeter of your home’s foundation.

What kills weeds permanently

Answered By: Xavier Bailey Date: created: May 26 2021

5 Natural Remedies to Get Rid of Weeds PermanentlyBlanket layers of cardboard paper and newspapers. Plants will grow when they have sunshine and water. … Spray concentrated vinegar directly on weeds. … Use your trusty assistant, liquid detergent soap. … Spread some corn gluten meal around your plants. … Scald the weeds with boiling water.Apr 25, 2019

Asked By: Cameron Smith Date: created: Dec 06 2020

Illustrated Guide to Smother/Kill Grass with Cardboard

  1. Identify the area you want to kill the grass.  I find it best to make a small outline with a shovel, or trim up the perimeter a bit.  Doing this helps me visualize what I want the final flower bed to look like.Lay down news paper or cardboard over the area you
  2. Lay down news paper or cardboard over the area you want to kill/smother.  If using newspaper, apply at least 10 sheet thickness.Weigh down the cardboard / news paper.  If making Weigh down the cardboard / news paper.  If making Weigh down the cardboard / news paper.  If making
  3. Weigh down the cardboard / news paper.  If making a vegetable garden, you may just need to use some rocks or bricks to kill the grass.  If making a flower bed, then just apply your mulch!  Now you have a biodegradable weed barrier that is just as effective as landscape fabric.

Here is a Short Video we made on the entire proces Here is a Short Video we made on the entire proces Here is a Short Video we made on the entire proces

Here is a Short Video we made on the entire process – Check it out!


Want to see some other ways to remove grass?  Chec

Want to see some other ways to remove grass?  Check out our guide on 5-ways to remove grass and start a garden.

5 Ways to Remove Grass

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Questions Answers

Question: Can I use just salt and water to get rid of weeds? And if so, how should it be mixed, and when should I apply it?

Answer: Yes. You can mix salt and water; three parts water to 1 part salt. You can also add vinegar for a better effect. The best time to apply is when there's no imminent rain to wash it off, and the weather is very dry as weeds will be already under stress due to lack of water.

Salty water is effective against young seedlings, but it'll need to be repeatedly applied to more mature plants with more developed root systems. It's not effective against deep-rooted perennials such as dandelions. Salt can damage your soil, killing microorganisms and worms and binding to minerals in the soil, so you need to take this into account if you're going to be growing flowers and vegetables in the future. On paths and driveways, this is unlikely to be a concern.

Question: How do I get rid of invasive horsetail?

Answer: Horsetail is deep-rooted perennial weed that will spread to cover an area if it's not dealt with.

You can try and fork out roots and shoots growing near the surface, but the weed can re-sprout from small pieces left behind. Glyphosate (Roundup or other brands) can be used as a chemical herbicide, and is best applied in late summer. It's a good idea to damage the shoots by bruising with a rake to help absorption.

© 2014 Eugene Brennan

2. Hugelkultur

Hugelkultur beds are old or rotten logs that are stacked upwards and can hold water and decompose slowly releasing nutrients into the soil. They are neat because you can plant on both sides because of the height.

 For full details on how to build a hugelkultur be

 For full details on how to build a hugelkultur bed check out this link. Read more about Hugelkultur here & here.

Identifying Common Garden Weeds

See my weed identifier guide for information on common weed names:A Guide to Names of Weeds (With Pictures)

© Eugene Brennan

Under Mulch or Under Rocks?

I find the best way to use cardboard for weed control is to use material on top to keep it from blowing away, and mulch and rocks work great when you follow these tips.

Using Cardboard Under Mulch

Laying cardboard down before you mulch your planters is a fantastic way to deal with pesky areas of weeds or grass that ruin an otherwise clean look. 

You can cover the soil entirely or just spot treat problem areas.

Lightweight mulch like coffee hulls or pine straw will not hold the cardboard in place in strong winds, so keep this in mind if this is your mulch material of choice.

Using Cardboard Under Rocks

When it comes to long-term weed prevention under rocks, cardboard may or may not be the right solution.

If you plan to spread out a standard three-inch layer of rock, it’s better to use a piece of landscaping fabric that won’t biodegrade and let weeds push up between the rocks.

ECOgardener Premium Pro Garden Weed Barrier Landscape Fabric | Editor Recommended Top Features Easy to install and setupEco-friendly Check Price On Amazon

On the other hand, if you plan to spread a deep layer of stone, using cardboard is cost-effective. 

I suggest laying down at least two layers, if not three, of cardboard under four to six inches of rock or gravel. Boxes from appliances are ideal for this type of application. 

The depth of the stones will prevent sunlight from reaching the soil even after the cardboard disintegrates, so weeds can’t grow.

Laying Down Cardboard as a Weed Barrier

When using cardboard to kill weeds and grass in a new planting area, start a few months or an entire season ahead of the time you intend to plant. Heifer International suggests removing any tape or labels from the cardboard packaging before breaking it down flat. Use plain cardboard, as printer ink can be toxic. After placing the cardboard in your garden, anchor it down with rocks or bricks. Then, hose it down with water to promote gas exchange to feed the soil’s microbes.

You can further improve the soil’s fertility by layering organic matter, such as compost, leaves, grass clippings or straw, over the cardboard about 6 inches deep, according to the California Native Plant Society. Over time and with the help of microbes and earthworms, the cardboard will begin to break down. If some cardboard is still in place when you’re ready to plant, you can cut a hole through it and place the new plants into the opening. If you’re in a dry climate or your area is experiencing a drought, water the mulched area about once a week.

What are the best treatments?

To kill weeds permanently in your garden, patio, path, drive or borders we recommend Glyphosate weed killer.

Glyphosate is the  most widely used weed killer in the world and is strong, safe & reliably eliminates most weeds in one application. 


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