Garden Basics

Ultimate Guide To Mulching Your Garden

There is a multitude of mulches that you can buy or make yourself. Mulch is like a blanket for your soil and helps retain moisture by up to 70%.

Choose a mulch that is right for you, your garden, and your pocket.

Mulching your garden is not an exact science, and with trial and error, you will find out what works best for your garden.

Mulching is a great addition to your organic garden principles.

Related Topic:  When is the best time to mulch?

What Is Mulch


Mulch is any layer of material that is spread over the soil to form a protective covering.

Why Mulch

Mulch Insulates The Soil

  • reduce weeds
  • conserves moisture
  • moderates the soil temperature in summer and winter
  • prevents soil erosion

Mulch Amends The Soil

  • protects the earth from evaporation
  • improves aeration
  • prevents compaction

Mulch Looks Attractive

  • disguises bare soil
  • organic mulches have a rustic appearance
  • inorganic mulches look more formal

Types Of Mulch


There are three main types of mulch, being, Organic Mulch, Inorganic Mulch and Living Mulch. Any mulch you use is better than no mulch at all.

Organic or Natural Mulch

Organic mulch is wood or bark based mulches, compost, straw, hay, shredded leaves, leaf mold, lawn clippings, cardboard or newspaper.

These mulches add nutrients to the soil when they break down. Earthworms also help feed the soil from the organic mulch as they bring the material down from the top as well as fertilize the soil with their castings.  

Organic mulch also keeps the ground warm in winter, cool in summer and moist all year round.

Inorganic Mulch

Inorganic mulch is rocks, gravel, brick chips, lava rocks, crushed stones, and stones.

Inorganic mulch is ideal for xeriscape gardens, rock gardens, and high traffic pathways.

Inorganic mulch does not break down and does not add any organic matter to your soil. Therefore it doesn't improve your garden soil.

Living Mulch

Living mulch is ground cover growing over the soil or plants densely planted, so there is no bare soil showing.

Cover crops are also a living mulch planted to improve the fertility of the soil.

Living mulch helps reduce evaporation and prevents soil erosion.

Types Of Organic Mulch

Wood Chips


Wood chips are a byproduct of pruning or cutting down trees. Choose natural wood chips shredded finely, that aren't dyed and scream, "look at me I'm mulch." Dyed mulch could be any wood, even treated wood.

Large chips of mulch can sometimes wash away in the rain as each large chip becomes a little boat and floats off into the sunset - or a part of the garden you don't want it to be.

Wood chips are a heavy mulch, so not more than 2 inches (5cm) would be recommended. Mulching too deeply will introduce problems into your garden.

Keep heavy mulches away from the base of the plant stems or tree trunks to prevent diseases.

Wood chip mulch may cause a nitrogen deficiency just where the chips meet the soil. Therefore wood chips should only be used in beds that have plants that are well established and have their roots well below this level.

Annual seedlings or transplants, as well as seeds, won't do well as their root system is too close to the nitrogen deficiency.

Chopping the leaves together with the branches will eliminate the deficiency if you have a wood chipper at home.

Wood chip mulches are long-lasting mulches for permanent garden beds.

Shredded Leaves Or Leaf mold - Composted Leaves


Leaf mulch is an excellent source of mulch.

Leaves are converted to humus by microbes, but it takes time. This years leaves collected in used compost bags, are next years mulch or compost. Partly decomposed leaves will also work well.

Recycle the plastic bags if using bagged compost, by filling them with garden clippings and leaves. Make a few holes in the bottom, wet them thoroughly, place them out of the way for about six months, and you will have a half a bag of homemade free "black gold."

Dried leaves can be used immediately on your garden beds as mulch in a thin layer.

Shredded leaves will break down faster. Run the mower with a bagging attachment over the leaves on the grass. When mowing the leaves, you will get grass clippings in the bag with the shredded leaves, which is an excellent source of nitrogen.

Or place them in a large barrel or trash can and shred them with the garden string trimmer or weed wacker.

Grass Clippings


Grass clippings can be left on the grass after mowing without a grass catcher. These clippings will break down quickly and nourish the lawn.

As a mulch on the garden beds, spread the clippings thinly so they can dry out before adding another thin layer. Too thick a layer will form a crust and water will not be able to penetrate.



Compost is a soil conditioner, and using it as a mulch as well as in your planting holes will give a double benefit.

If your soil needs improving and your garden is a fair size, then compost is as good a mulch as any. It can be bought in bulk or bags. Bags are more convenient but more pricey.

Using compost as mulch eliminates the need to rake up your mulch to amend the soil.

My soil is clay, and over the years it has improved drastically using compost as a mulch. It has better drainage, and the pH has significantly improved. The worms and plants are loving it. I compost every spring and fall and sometimes in between if necessary.

Compost does decompose faster than most mulches.

Straw Based Mulch


Straw is leftover bare stalk after the harvest and is classicly used in the vegetable garden. It is readily available and cost-effective in rural areas.

There are various types of straw-based mulch, such as pea straw, wheat straw, lucerne, rice straw, lupin, sugar cane straw, pine straw.

Look for a supplier that has guaranteed weed-free straw mulch, which is certified organic. This certification will eliminate the straw that has been sprayed with herbicide.

One bale of straw will yield a large amount of mulch as it is compressed into a small bale. It's easy to handle as it is relatively light, and a little goes a long way.

Break the straw up from the bale before placing it on the garden beds and not in clumps.

Straw is light, so the depth of the straw layer can be up to 6 inches (15cm). Straw mulch decomposes quickly, so top up whenever necessary.



Hay is harvested while it is still green and can have weed seeds unless you get high-quality hay. Even then, you will still have some weeds.

If you get hay the year before using it and leave it to decompose partly, most of the seeds will have sprouted by the time you use it in your garden.

When hay starts to decompose, it leaves a rich layer of nutrients for your plants. More so than straw.

In very wet areas using hay as mulch can increase slugs in the garden.

Prunings From Your Chipper


Anything that needs pruning can go through the chipper shredder and makes an excellent free mulch.

Shredded branches are high in carbon, but low in nitrogen, and the leaves are nitrogen-rich. Shred the two together for good soil improvement.

Free Organic Mulch From Your City

Contact your city to find free mulch.

Examples are this one for free mulch near Los Angeles or this one for free mulch in Santa Barbara

Types Of Inorganic Mulch

Stones And Rocks


Using stones and rocks as mulch will depend on where you live as these become very hot in the sun.

Stones and rocks can heat the area considerably, so it is not advisable to place this mulch in the sun in garden beds unless planted up with hardy sun and heat-loving plants.

Places, where stones can be used as mulch, are areas such as imitating a dry creek bed, xeriscape gardens, Mediterranean landscaping, rock gardens, succulent gardens, and gardening in desert regions.

Crushed stone walkways between raised beds are another use of stone mulch.

Stones are more expensive initially but will be cost-saving in the long run.

Stones don't decompose and therefore, will not add any nutrients to the soil. They are more expensive initially but will be cost-saving in the long run.

Landscape Fabric Or Plastic Sheeting


Most times, in a garden bed, landscape fabric is not necessary or needed. When the mulch starts to break down in a garden bed, it feeds the soil. Landscape fabric will isolate the mulch from the ground.

I have laid landscape fabric under my stone pathways where nothing is planted to prevent weeds. This only works on the weeds and weed seeds that are already in the soil. Many weed seeds are blown in by the wind and will settle down on top of the mat. This fabric eventually breaks down and isn't effective.

Plastic sheeting is sometimes used as a mulch in newly planted beds. This, like landscape fabric, will not amend the soil.

Rubber Mulch


Made from ground-up rubber tires.

There are recycled rubber tree rings that fit around the base of the tree or rubber mat for walkways/paths. These rubber mulches will eliminate weeds but won't add any nutrients to the soil.

Rubber mulching mats are sometimes used in playgrounds.

Living Mulch


What is living mulch? Living mulch is covering the soil with a plant such as ground covers, low growing grasses or any dense plantings covering all the bare soil.

One of the most common living mulches is your lawn, which covers the earth and keeps weeds at bay.

Vegetable gardeners sometimes use cover crops as a living mulch at the end of the growing season or even during the growing season. In areas with an icy winter, the cover crop protects and feeds the soil for spring planting.

Cover your garden bed with a low growing annual that self-seeds, such as sweet alyssum for a carpet of color and a beautiful, easy-to-grow living mulch.

Wildflower mixes make an excellent living mulch. Find suppliers that sell mixtures that are suitable for your region.

Which Mulch Is Best For Vegetable Gardens


The ideal mulch for a vegetable garden is those mulches that are light in weight.

The most common mulch for veggies is straw based mulch. It's relatively cheap, breaks down well, keeps weeds at bay, and reduces the need to water often. Get whichever straw based mulch that is locally available.

Finely ground pine bark is light and easy to spread and an excellent soil conditioner for vegetables.

Shredded leaves are convenient and free every fall. You know they are free from pesticides, and they are easy to work with once shredded with your mower or trimmer.

Water your veggie garden well before you mulch and the mulch covering will retain the water in the soil.

Chopped up straw, such as pea straw, is ideal for new vegetable seedlings and will not smoother the new seedlings. Pea straw has smaller pieces and is perfect for those new delicate plants.

Mulching Containers


Containers dry out quickly and should be planted up with moisture-retaining granules as well as a mulch on top.

Organic or inorganic mulch can be used for your containers. Inorganic mulch, such as stones used on succulents, will not improve the soil.

Dried grass clippings and leaves make excellent and inexpensive mulch in containers.

Mulching On A Slope


Heavy rain can wash your mulch away on a steep slope, so how can we mulch in a hilly area?

Matting mulches such as straw and hay are an excellent mulch for a slope as the matting tends to hold the mulch in place.

A netting covering heavy wood chips could be one way. But in my experience, after trying numerous ways, planting a living mulch has been the most successful and prevents soil erosion once they are established. Drip irrigation works well on a sloped area.

Use plants that will anchor themselves well on the sloping bank.

Dig swales across the contour of the slope or above every newly planted plant. The swale will stop the water from running down the hill. Place the plant below the swale, so the water collects on the swale and soaks down to the plants.

Plants that spread and root with a matting root system will cover the slope in a few seasons.

Over Mulching


Overmulching can smother your plants if it is too deep. The lower area of the soil cannot get oxygen, and the plant will eventually die.

Never make a volcano mulch around a tree, always leave a gap between the mulch and the tree or shrubs stem.

Bulk Supplier Mulch


Bulk mulch is cheaper than bags, but you will need space for the mulch pile.

If you do not have level paths and easy access to your garden, buying mulch in bags may be more manageable.

Use the mulch calculator to gauge how much mulch to purchase.


At the end of the day, the best mulch is the mulch you can easily source.

No matter what mulch you use, its crucial that it is free from insecticides and pesticides.

Ultimate Guide To Mulching Your Garden


  • Mulch protects the earth from evaporation, reduces weeds, improves the soil, moderates the soil temperature and prevents soil erosion.
  • Organic material will have an added benefit of enriching the soil.
  • Do not over mulch.
  • Make your own mulch for free.
  • Find the best mulch for you, your garden, your region and your pocket.

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