How to Lay Mulch Over Old Mulch?

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Mulch is usually made of organic matter around the base of a plant, shrub, or tree. Mulch keeps water in the soil from getting too compacted when it rains. It also slows down the loss of earth and the flow of water.

Most of the time, landscapers and gardeners use natural, least-processed or semi-processed Mulch to keep weeds down, create moist soil, insulate plant roots, stop dirt from washing away, and improve the ground. If you lay Mulch over old Mulch, there’s no need to take these mulches away.

Also, Mulch helps keep the temperature of the soil stable and encourages the growth of microorganisms and worms in the soil. As Mulch breaks down over time, it lets nutrients and organic matter into the ground. Replace the Mulch as needed to keep a 2- to 4-inch-thick layer on top of the soil. Here, I will tell you and everything about how to lay Mulch over old Mulch.

Things to Know Before You Lay New Mulch Over Old Mulch

When people talk about “old mulch,” they mean Mulch that is still there after a year. And people may consider they should remove the old mulch or not before laying down the new mulch.

Here are some clear cut reasons when you should remove the old mulch and when you should not:

When You Should Remove the Old Mulch Before Laying New Mulch

Some gardeners and landscapers will prefer to use new mulch over existing organic, less-processed or semi-processed mulch materials for the following reasons:

  • To control weeds, retain moisture and insulate plant roots and soil.
  • To improve soil aeration as well as water retention with an organic mulch blanket.
  • To not have to spend time removing these types of organic mulch materials because they can simply be put over top of existing mulch or if you prefer, new layers of organic mulches can be added directly on top without needing to remove previous layers. Good examples of the mulch that you should not remove are pine needle, cedar, cypress, wood chips mulches because they do wonders for your soil through so many ways. These mulches break down slowly and provide valuable organic material in the soil. They also helps with water infiltration which is super important during dry periods and can add to so much more!
  • It saves you money, time, and work. Getting rid of old mulch can be hard work and take time. It can also cost you more money because you must put down more mulch all over again.

When You Should Not Remove the Old Mulch Before Laying New Mulch

You should remove the old mulch completely for the following reasons:

  • If the new mulch your are going to lay down is not the same type as that of your old mulch already laid down, then you should remove the old mulch first completely.
  • If your old mulch has faded color and is damaged in case of inorganic types, then you should remove them completely.
  • If your mulch is clearly showing symptoms of sun burns with deteriorating quality then you should remove it.
  • If your mulch is showing symptoms of any fungal disease then remove the affected layer of mulch asap and add fresh layer over it to kill all fungi.
  • Take a scoop of old mulch in your hand and check if it can be used again or not. If it is same as soil then you need to apply new mulch from zero and remove old mulch. Please note that only remove inorganic mulch if its particle size is reduced. Never remove organic mulch if it is decomposed into soil.

Basic Steps to Lay Mulch Over Old Mulch

As written above shows that the Mulch over old Mulch is beneficial. Mulch over old Mulch is not tricky because our soil is already ready for mulching. We do not need to add barriers and slope the soil. Here, I will tell you the basic steps to Mulch over the Mulch.

Equipments Needed

Shovel: You will need it to drop mulch to wheelbarrow

Rake: You will need it to spread the mulch

Garden spade: To remove unwanted weeds and grasses

WheelbarrowTo carry mulch or wastes from one place to another

Gloves: You will need it to protect your hands from dirt


1. Select the Right Type of Mulch

Select the right type of mulch that you will be laying over old mulch. A thumb role that you can follow here that you will save you from doing major mistake is:

Always lay down new mulch of type that is same as that of old

Also prefer organic mulch over old mulch when you select the mulch.

2. Look the Mulch Need Replacement

Now look at the mulch that needs repalcement.

Tip: How to check if your old mulch is still reusable or not?

Grab a little or two of the mulch. Now look at the mulch and see if it’s broken down into adequate sized chunks. It’s not really well suited to act as a base for garden soil, but you may be able to make use of it if it still mimics its former self in this way. Use your judgment here: if the mulch is just now starting to break down and looks like finely ground up dirt, it probably won’t work too well in your garden. If it doesn’t have enough substance and size, however, you can try mixing some other types of products with this one to make it usable again.

3. Get the Right Quantity of Mulch

Get enough Mulch to cover the area you want to protect. North Carolina State University says that nine cubic feet of Mulch will cover 100 square feet and make a 1-inch layer. You must calculate your mulch correctly so you can cover your all area with an equal thickness of 3 inches everywhere.

To simply calculate the mulch you need, you check the length and width of your area where you want to lay new mulch over old mulch. You can then multiply length and width to get the square footage number. After that follow the formula below to calculate the mulch bags you need to lay over old mulch (please note the thickness you need in the formula):

  • 2 cubic foot bags: Square Footage / 12 = Total bags needed for a 2” inch thick layer of mulch.
  • 3 cubic foot bags: Square Footage / 18 = Total bags needed for a 2” inch thick layer of mulch.
  • Bulk mulch: Square Footage / 128 = Total scoops needed for a 2” thick layer of mulch.
Mulch the Protected Area

4. Prepare the Soil

With edger prepare the edges and remove the old mulch where needed.

Also, clear away any old mulch from an area of 1 to 2 inches if you are laying mulch around bushes or flowers, or trees. If you put Mulch too close to the branch, it can cause the bark to rot. If you need to, use a piece of string to mark the 1 to 2-inch circumference.

Clear Old Mulch From Plant Stem

5. Spread New Mulch

Spread the new mulch on top of the old mulch, starting at the edge of the area around the plant’s base that you have cleared and working outward. One more inch of fresh Mulch should be enough.

Spread New Mulch

Here is also a quick video I found useful for me and hope it also helps you out to put mulch over old mulch and precautions you can take throughout this procedure:

Final Verdict

Mulch over old Mulch saves money and time. For mulching over old Mulch, you take enough Mulch that covers your required area, removes 1 to 2 inches old Mulch just from the stem of the plant and put new Mulch. There will be no side effects of Mulch over old Mulch, and these three easy steps will be helpful for you.

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After doing my master’s in agriculture, I went on with this field for more than 15 years because I love working in green. I have experienced using modern machinery and techniques that can help farmers and landscapers to achieve something great. My goal will be to deliver you the best reviews and information to make the right decision.

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