Our house is in need of mulch around bushes, trees etc.
We are finally getting around to address this, and have calculated we need two yards to get around 2 inches of mulch onto everything. We live in the northeast and get a lot of snow.

Is it best to wait until next spring? If we choose black mulch, will it degrade too much where we just need more next spring? Or does it last a couple of seasons and only requires "sprucing" up.

We accept the previous owners did not do much and the landscape requires a lot of work and maintenance, but we also do not want to put in all the work of covering everything in mulch only to have to do it again in 6 months.

Can anyone enlighten me to how long mulch roughly lasts? Also is 2 inches a good amount, too much? too little?


3 Answers 3


A good layer of mulch should still be apparent after one year of laying. If the mulch is gone after one year, you'll need to add more next time.

Being a busy landscaper myself, I don't have time to get everyone covered in spring, and pretty much mulch whenever it's not freezing out. I find that the mulch generally lasts about the same, no matter when you lay it, but when laid in fall, it will be comparatively faded by spring, and although still there, it won't be as attractive as 'everyone else's' new jobs. Some people don't care, some want it freshened up. This I do by top-dressing, or sprinkling new mulch on for appearance, not wanting to change the depth too much. This is just for color.

Or you can use premium bark mulch, which fades some, but doesn't as badly as black dyed chips. Those two mulches are the most common in my area, followed by brown dyed.

About when to lay it, it doesn't really matter, as far as the plants are concerned. I'll give a list of pros and cons for your case:

  • spreading mulch this fall

    • pros: it will last until next fall, it will help suppress spring sprouting weeds, it will protect plants better
    • cons: It will look more faded, when everyone else's spring laid stuff is looking sharp
  • spreading mulch next spring

    • pros: it will look sharp when everyone else's do, it will last until next spring, it will better suppress fall-germinating weeds
    • cons: it is usually getting thin by the next year when spring weeds start germinating

I've met quite a few people who swear by fall spreading, and quite a few others who mulch 2-3 times per year (or worse, pay me to do it). It's pretty much up to you and what you like.

Depthwise, I usually go by what is already there. On an unmulched bed, or nearly so, I often use more than two inches, but if there's a good, full layer of mulch from the year before, I'll basically add only a covering for cover. Especially under eaves, look for undecomposed mulch piling up, and remove that before you add new.

Too much mulch cakes up, creates a moisture barrier, and can harm plants. Premium bark can be laid initially thicker than dyed chips, because 1), it packs down a lot more and 2), it tends to decompose faster.


The purpose of mulch is to keep weeds down, feed the organisms of the soil, retain moisture and improve whatever soil it is that you have. Ideally, it should look beautiful. Bare soil is not a natural thing, but covered with a great mulch it'll be beneficial to the ecosystem of which even you are a part of and your plants will not flourish without.

Un-decomposed mulch will not feed your soil organisms. Bark and chips and plastic are un-decomposed mulch. They help with moisture retention, not so much with weed suppression. Soil organisms are critical to the health of plants. A good soil is full of organisms both micro and macro. Bacteria is an example of micro organisms, earth worms macro. Without a thriving community in your soil your plants will suffer. They will survive but continue to die slowly. Plants and soil organisms are absolutely necessary for each to survive.

One of the best things you can do for your landscape is to use DECOMPOSED organic mulch. If you make your own, you can probably trust the product. Decomposed organic mulch (not rock, not bark, chips and certainly not plastic) is what feeds both micro and macro organisms in your soil. It is like putting up big neon sign saying, "Great Eats Right Here"...They'll come to you and they'll reproduce...these organisms come up out of the soil and eat decomposed organic material, return into your soil profile, poop the stuff out and in doing so they are aerating your soil, mixing organic matter into your soil and improve your soil. More importantly there is an important symbiotic relationship between your plants and these organisms. The plants actually 'pay' or provide these organisms with up to 40% of the carbon they produce. The organisms do mining, aeration and get nutrients to the plant roots so the plants get the chemicals they need to make their own food. With which they give back to these organisms.

Without decomposed mulch and small amounts of added nutrients, this process takes a nosedive. Urban areas and suburbs are becoming deserts because of the use of bark and plastic. There is nothing for birds and beneficial insects to eat. The cycle is stopped. Your plants will linger, your soil will become compacted and it will take more water to reach the roots.

Most people are unable to see the difference.

The bad news is that a source of dependable decomposed mulch is hard to find. Most are full of pesticides from homeowner use and weed seeds. There is one I have found that I trust and am trying to get even experienced gardeners to try and that is decomposed human poop mixed with sawdust and professionally decomposed. The final product is NOTHING like the original ingredients. No smell, no sticks, no rocks, no weed seeds, no pesticides and it is beautiful! Dark taupe in color (not black, how natural is that?) and fine, fine textured, smells like earth as it should. It is also tested, 5X!! A reputable place will be able to give you a current test to show exactly what it is composed of. No other mulch that I am aware is like this.

The companies producing this stuff can deliver it, you can pick it up in a truck or they can even blow it onto your beds or lawn. It is not expensive but whatever the cost it is the cheapest, most intelligent way to care for your soil and plants. Install 2" (I might go and chop down big weeds but I like to reserve my energies and body) right on top of all bare soil and weeds. No weed seeds are included and the multitudes of weed seeds in your soil will never be able to germinate. Any weeds that do make it through are easy to pull up.

This stuff will be promptly eaten and mixed into your soil by the very happy organisms. This helps to stabilize pH, adds nitrogen, helps retain moisture. Within a week, I am so very serious, you will see your plants start looking like they should, greener, stronger growth, more able to deal with disease/insects.

I've had blue clay and inside of one season watched as black streaks colored the blue with organic matter and air. All I had to do was put a couple of inches of this mulch on top of the soil.

Besides tasks like mowing correctly and at the correct height (PNW grasses no shorter ever than 3"), aerating your lawn, fertilizing properly for lawns and plants (under fertilizing is better than over fertilizing...well, over fertilizing will make the plants reduce their carbon donations to the organisms because they are getting more than enough nutrients and a little more fertilizer than that will KILL your plants), watering deeply after allowing your soil to dry out (to train your plants roots to grow deep and become drought tolerant)...the best practice one can do is to mulch your soil with decomposed organic mulch. This aerates your soil (plant roots need air), adds organic matter into the soil which stabilizes the pH, adds nutrients, helps to retain moisture, nutrients aren't leached away into the water table, keeps roots protected from extremes of temperature, feeds the organisms plants need to uptake nutrients and to bring them nutrients, stop germination of weed seeds that would compete with nutrients and water, your plants will be able to fight disease and insects that come their way, they will be vigorous and beautiful, your soil whether clay or sand will continue to get better and better...all you have to do is replace this mulch as it does disappear into your soil and cause all this other stuff to get done without anymore effort on your part. And every other year is what I am used to for myself and my clients. If your soil is particularly poor, you might have to replace it the next year after the initial coat as the starving organisms gobble it up and drag it into your deficient soil. This only shows your soil is coming back to life, the mulch is being incorporated into your soil and not being washed away! If it stays, your soil was in a better condition. It uses what it needs.

This one practice, feeding your soil with decomposed organic mulch by just dumping it on top solves so many other problems it is worth the little time, effort and money invested. It is like killing 4 birds with one stone.

Call your sewage treatment plant to see who and where they produce this stuff. Up in the Seattle area it is called Gro-Co.

There is only one down side. It has higher levels of heavy metals (from our medications) so you shouldn't use them on vegetable gardens. I won't mention that most of the world outside the U.S. uses human manure for most of their agricultural production. Yet these other countries won't accept our GMO crops...A lot of our tap water has higher levels of heavy metals than does this stuff. I still don't use it in my vegetable garden...but tempted.

It is tough to change your paradigm when so many people use bark and plastic for mulch. It is simply wrong and doesn't reduce weeds...it makes soils that weeds themselves chose not to grow in. This answer was long, I apologize. Even people that are well-educated and experienced gardeners have a hard time not using the oh so popular bark and plastics.

If you do try to find this stuff in your area and do your own research...and try using this, please let us know if you could tell the difference, how it was with weeds, could you tell the difference in your landscape plants and how long it took to see how much more beautiful it was than bark. Finer texture and a more dirt-like color should really highlight your plants versus detract. Did you notice more birds and wildlife? We humans do best by copying nature to get what we want instead of trying to force natural things to do our bidding. Bark will eventually be in the same category as astroturf and polyester. Grin. I truly hope this makes sense to you.

  • 1
    Whoah, what a huge answer. I agree for the most part, just wanted to say that completely decomposed organic matter doesn't form a weed barrier (weeds will love to grow right in it), and also, other mulches can feed the soil too, they just ave to be broken down first. In my area, bark mulch is completely natural and does help suppress weeds better than a sterilized, balanced compost, and builds the soil, too - you just have to add some N and wait for decomposition.
    – J. Musser
    Commented Aug 20, 2014 at 3:21
  • 1
    I think there is a good reason that people use shredded bark, and it's mostly that it isn't decomposed. Plant's can't germinate well in it, it's renewable, looks sharp, keeps things moist, protects during winter better than compost, feeds the soil, builds the soil, improving OM content, adds vital micronutrients, the list goes on and on. I think you were wrong to talk it down how you did. I agree on the plastic, gravel, and for the most part dyed chips, but bark is great. Ill add a layer of compost, and then a layer of bark, but I think there are qualities in bark that poop just can't fill in.
    – J. Musser
    Commented Aug 20, 2014 at 3:30
  • 1
    Bark in my area is completely renewable, taken from the local sawmills, which source from forests that are being carefully tended, replanting more trees than are being cut, in addition to the trees that germinate on their own. There isn't really much else to do with all the bark.
    – J. Musser
    Commented Aug 20, 2014 at 3:33
  • 1
    Thanks, for the helpful answer, I am in the process of beginning to compost, we get about a bazillion (probably more) leaves in the fall, our compost bin made great work of some of it (we still had 75 bags). Which I have now begun to stir into non grass areas . The previous owners left the landscape in terrible shape, very compacted, washed out soil around bushes and trees. So I am in the process of trying o return the soil back to a healthy mix. I also want to add mulch for that clean nice looking landscape as J. Musser describes.
    – treeNinja
    Commented Aug 20, 2014 at 13:33
  • Non-decomposed bark takes years to break down. During which the DECOMPOSERS that are everywhere, including our soil, get busy decomposing. These decomposers need lots of nitrogen to do their work. It IS readily available and if it is very, very fine doesn't look bad because it is a uniform texture. But does nothing for your soil and plants. Birds disappear as earthworms and other micro organisms will find a different place to inhabit that does provide food for them. It is hard to change such a popular paradigm but like I said, I will take the risk to tell others to rethink this practice!
    – stormy
    Commented Aug 20, 2014 at 21:11

Here in Northern CA (SF Bay Area) we usually do 3-4 inches of total depth for bark mulch. I do a little less around plants that have shallow roots, such as camellias and rhododendrons. It typically lasts a couple years, but our weather isn't as harsh as yours. Mulch breaks down over time (which is good for the soil) so obviously if you use less you'll have to refresh it sooner.

I prefer not to use colored mulches because I have no idea what goes into the dye that's used.

The formula for figuring out how many yards to order is:

(sq feet) * (mulch depth in feet) / 27

For example if you have 200sf to cover and you're mulching with 3 inches, you need

200 * .25 / 27 = 1.85 cubic yards

  • Well let's say you leave a 2-foot diameter circle bare around each plant. The area of that circle is pi * r^2 or 3.14sf. So if you have 10 plants, that's 31.4 sf that you subtract from the total square footage. Then do your cubic yardage calculation from there.
    – Andy
    Commented Aug 18, 2014 at 16:53
  • J.Musser, you must be self-employed to be able to order soil, gravel, mulch by the yard by FEEL. Grin!!! Andy most stuff is done in 2" or 4" and simply taking the square footage and dividing by 81 gives you the yardage to order to cover 4"...divide by 2 to get 2". Just another way to think, calculate and make sure you don't over or under order. Both are costly...J. is right about too thick mulch getting against the bark of trees, burying the roots of shallow rooted plants and perennials too deep...! But BARK is BAD. I'll go to the mat for this!
    – stormy
    Commented Aug 20, 2014 at 1:50
  • @J.Musser, are you saying everything should not get the same height of mulch? Can you elaborate a bit? I understand you do not want it around tree trunks but anything else I should be aware of?
    – treeNinja
    Commented Aug 20, 2014 at 13:35
  • It was mentioned a bit above but shallow rooted plants such as Rhododendrons, Camellias, Daphne, Azaleas...can be killed with too much mulch, or soil installed on top of their roots. They need more air and an extra inch can make a difference. Plan on no more than 1/2 inch of human poo mulch or an 1 -1 1/2 of bark. When you install mulch or soil dump wheelbarrows full on the soil and spread that particular load to the correct height. Don't spread it to cover the soil as you won't be able to tell the correct depth. Go back and fill in bare spots...
    – stormy
    Commented Aug 20, 2014 at 21:28

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