Guide To Mulch: What Is It And How To Use It?

Kenneth Wilson

If you’ve seen our guides on maintaining a green lawn or killing weeds, then you have probably come across the word ‘mulch’. This material is commonly found in gardens, flower beds, and other areas in a yard. 

There are plenty of benefits when using mulch, and these are not limited to keeping your lawn green or getting rid of weeds. But to gain these benefits, mulch should be applied properly. If used incorrectly, then it wouldn’t help, or worse, it would have an opposite effect.

Continue reading to find out the definition, kinds, and benefits of mulch as well as how to use this material.

What is Mulch?

Mulch is a general term for any material used as a top dressing on a garden, flower beds, or lawn. It is a covering that is usually laid or spread over the surface of the soil.

Different Kinds of Mulch

There are two main categories for the different kinds of mulch, which are organic and inorganic. It is recommended you choose a material based on its function, appearance, affordability, availability, and maintenance level. To help you decide, here are the pros and cons of using organic and inorganic, as well as the various materials that are commonly used as mulch:

Organic Mulch


  • Better soil fertility
  • Improve organic content
  • Some materials provide nutrients
  • It helps prevent soil erosion


  • Decomposes and have to be replaced often
  • Some materials may contain weed seeds
  • May attracts pests

Compost and Composted Manure

This material is usually a combination of food scraps and other organic materials such as grass clippings. It can be used on flower beds, shrub beds, and vegetable gardens as a coating or for side dressing. When used during the growing season, they provide more nutrients. It can also be used after the growing season to improve soil quality, which is better for future growth.

Shredded Leaves

Nature provides a free mulch and these are shredded leaves. This material is made out of fallen leaves that are shredded with a lawnmower or leaf shredder. These can help attract more earthworms into the soil, but be careful when using them since they may also be carrying a disease or cause insect problems. Check them thoroughly and make sure they are not toxic. You may also want to see if it would look good on your lawn because some people don’t like how it looks.


This woody material is made out of tree bark, and it can be shredded or chipped. This can be used for top dressing beds as well as placed around trees, garden beds, and shrubs, or areas near foundation plantings, walkways, and pathways. When placed near trees, make sure to keep it away from the base of the trunk to prevent rot and rodent damage.

Bark lasts longer than other fine organic mulches, but it would be difficult to mix into the soil, so you would have to move it if you’re going to add plants in the same location. It can also attract carpenter ants as it decomposes slowly.

Grass Clippings

Another free and readily-available material you can use as mulch is grass clippings. After mowing the lawn, preferably with a mulching mower, the clippings can be left to improve soil fertility or be collected to use in unplanted areas or to prevent weeds from growing in remote areas of a lawn.

But the downside to using this material is that it mats down and prevents water from passing through. They also have a high water content, so they quickly decompose and oftentimes get smelly. So if you do want to use them, let the grass clippings dry for one to two days after mowing before applying it on beds. You also shouldn’t use grass clippings from a lawn that has been treated with chemicals such as pesticides, herbicides, or weed killers.

Pine needles

Needles that have fallen from a pine tree can also be used as mulch after they turned brown. This is a light and inexpensive material that takes years before it decomposes. It can be used on flower beds, shrubs, and even pathways.


Newspaper has become a popular mulch, especially when most of them started using organic dyes. It can be spread as it is or shredded first. This is often used to keep the roots moist since it retains moisture well. It also helps prevent weed and maintain soil temperatures. For better results and appearance, you can also place another organic mulch on top of the newspaper.

Straw Hay

This is an inexpensive material often used in vegetable or fruit gardens. It can also make a garden bed look more attractive, especially when it is chopped. But be careful when using this material since it can bring weed seeds to your lawn, garden, or flower beds. This also shouldn’t be placed near fire pits or anything that produces fire since straw hay can become a fire hazard.


Another inexpensive material that can be used as mulch is sawdust. It is debris from milling wood and is commonly found in soil stores or nurseries. Sawdust may make the plants look sickly, and when this happens, just add fertilizer.

Inorganic or Synthetic Mulch


  • Takes longer or does not decompose
  • Saves time from reapplying or replacing often
  • Fewer expenses
  • Does not attract pests


  • Does not provide nutrients
  • Appearance is affected by sun exposure

Landscape Fabric

This is a popular inorganic mulch because it is porous and often has good drainage. But it can sometimes get blocked, and when it does, you will see puddles on top of the fabric. For better drainage, some people cut holes in it before placing around foundation plantings, shrubs, and trees. This will help water and air pass through, which will provide roots with the nutrients that they need.


If you have plants or areas that don’t need to be fertilized often, you can use plastic as mulch. This will save time from maintaining these areas with work such as weeding. But when using this material, make sure that there is always sufficient moisture since plastic can get very hot. This may make the soil unhealthy, or worse, kill the plants' roots.

Gravel and Stone

For garden beds that need good drainage or warmer environments, you can use gravel and stone as mulch. Water can easily pass through and this material can retain heat. But compared to other mulches, it would be harder to remove or transfer, so only use this in beds or areas that you won’t be renovating for some time.

Benefits and Drawbacks of Mulch

Mulch is often used to control weeds, but there are other advantages of using one, which is not limited to preventing weeds. It is also beneficial for the soil, plants, beds, lawn, home’s curb appeal, and homeowner. Here are some of the benefits and drawbacks of using one:


Discourages weed growth

Mulch is commonly used to suppress weed, especially during growing seasons. By preventing light from reaching the surface of the soil, weeds will grow slowly or not grow at all.

Improves soil quality

Using mulch can help improve the quality of the soil. Mulch helps decrease water loss or runoff from the surface of the soil as well as retain moisture, which is important when you have sandy soils. It also maintains soil temperatures, keeping it cool on a hot day and warm on a cold night. Mulching reduces soil erosion and compaction, and when using organic materials, it helps improve soil fertility.

Healthy garden and protects plants

Since it reduces weed growth and improves soil quality, using mulch is also good for plants and their growth. This also reduces plant diseases since it prevents soil from splashing onto the leaves and keeps the plants clean. It protects plants from harsh outdoor elements and discourages pests if the mulch is used properly.

Saves time, effort, and money

Using mulch will lessen your spending, time, and effort in your garden. You can save on these because there is decreased water runoff, less weed to remove, and spend less on chemicals such as weed killers.

Better landscaping

Mulch can also be used to improve the landscaping of your home. If you have a tree, you can use it to make the area around the tree look more attractive. It can even be used to protect trees so that there is a lower chance of mowing or hitting a tree. Some people also use mulches to create pathways in a lawn or garden.

Improves appearance and curb appeal

Using mulch makes gardens and beds more attractive, especially when the material complements the plant and overall look. It adds color and texture, enhancing the beauty of your outdoor area. In turn, it can also help increase a home’s curb appeal.


There are also drawbacks of mulching, but only when mulch is not used properly. You can find tips on how to use mulch as well as what not to do in the next section, but if you’re curious, here’s what could happen when mulch is applied incorrectly:

Harm plants

If one over-mulches, it can damage plants by burying, suffocating, and overheating them. This will prevent air and water from reaching the plant’s roots.

Attract pests

Placing mulch near plants stems can attract snails, slugs, rodents, and other pests.

Damage trees

When placed wrongly around trees, it can bring diseases and decay as well as attract insects, rodents, and cause decay.

Steal nutrients

Some kinds of mulch can steal nutrients or minerals such as nitrogen from the soil.

How to Use Mulch Properly and What Not To Do

To make sure that you can gain all the benefits from mulching, you should know how to properly do it as well as what to avoid. Here’s what you should do and not do:

Before layering

Before you apply mulch, the area should have clean and weed-free soil. The soil should also be watered deeply. You should also know where the material comes from, especially with organic mulches, since it may contain weed seeds. If you use mulch carrying these seeds, you’ll have more pesky invaders to get rid of.

Applying mulch on beds

It is important to know how thick you should apply the mulch so that you don’t over or under mulch. The depth depends on the plant, but typically, it should be 2 to 3 inches deep when using organic mulches. For inorganic or synthetics ones, it can be shallower. 

Note: If you want organic mulch to last longer, it should be dry and woody. 


This especially applies to organic mulches, which you have to replace more often. It’s best to re-mulch at least twice a year to ensure that the mulch is clean and that the area will still look great. When replacing mulch, make sure to remove some of the old material that has built up over time. After a few re-mulching, you don’t want the first layer of mulch you applied to still be there.

Preventing drawbacks

Some mulches may attract snails and slugs to your plants. You can use diatomaceous earth or wood ashes around these plants to prevent pests from going near them.

Some organic mulches such as fresh wood chips, sawdust, or other light-colored woody mulches can steal minerals like nitrogen from the soil. When using these materials, add nitrogen-rich fertilizers to the mulch to keep your soil healthy.

Do not...

  • Over-mulch: It’s recommended not to mulch more than 3 inches so that the plants will still have access to air and water. Over-mulching can suffocate and bury plants, which could hinder their growth, or worse, kill them.
  • Apply mulch on dry soil: The soil should always be watered deeply before putting mulch on top.
  • Layer near tree trunks: When landscaping around trees, the mulch should be placed 6 to 12 inches away from their trunks. If you mulch too near, it can cause diseases and decay, and attract insects and rodents.
  • Use materials without knowing where it’s from: Make sure to get your mulch from a reliable source since the material could contain weeds seeds, insects, and diseases. You don’t want to infect your lawn or suddenly have a weed infestation.
Kenneth Wilson
April 14, 2020
Yard & Garden

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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