Ecosystem Mimicking / Garden

Rock Mulch: Why You Shouldn’t Choose It and What to Do Instead

A newly married house-shopping couple, my husband and I chose our current home in large part because everything was already done for us. It was not a fixer-upper, the paint colors were chosen and done, the curtains were left for us, and the landscaping was already done. We are not handy people and I, at the time, thought myself incapable of any kind of design (which was quite wrong indeed).

What I once considered an asset, though, soon became the bane of my existence. This landscaping had been meticulously maintained with copious poisons, and that was simply not something I was willing to continue. The first summer at our new home I found myself, 9 months pregnant in the scorching heat of July, hand pulling hundreds of weeds out of the rock landscaping.

The next summer I began the long, arduous, and back-breaking process of removing rock mulch. Seven years later, I still haven’t finished, and the rocks I have removed from their beds are simply piled up on the north side of my house, because I cannot get rid of them. We will have to pay a crew with big machinery a huge chunk of dough to come get them and haul them away for us. 

Piles of rock mulch taking up space, because I can't get rid of it
Isn’t it lovely? This is an old picture; it’s much higher and more precarious now. Some day we will pay someone to haul all this garbage out of here.

Rock mulch is high maintenance

Rock mulch is intended to be a low-maintenance mulch, but I find that to not be the case. From what I’ve observed and read over the years, this is what needs to be done in order to maintain the look property owners do with rock landscaping.

1. Lay landscape fabric and apply rock mulch.

Since landscape fabric is woven of synthetic material, it can last quite a long time. However, it does not last forever. It will need to be replaced once in a while. Landscape fabric around plants is a royal pain in the neck. You will need to deal with cutting and moving landscape fabric any time you want your plants to grow or you want to divide them. You’ll also have to cut holes in it any time you want to add new plants.

The rocks we use for landscaping typically comes from river beds, apparently. What river beds? I don’t know. What did this process of acquisition look like? I don’t know. How much damage did the removal cause to that ecosystem? I can guess probably a lot. Even if you can’t find straightforward answers to questions like these, it is always important to ask them. Also, as mentioned above, hauling around and manipulating rock takes a lot of fuel from heavy machinery. Rocks are heavy and cumbersome. 

2. Apply pre-emergent herbicide at least yearly in early spring.

This needs to be done every year, because although landscape fabric can block already existing seeds and plants, any new seeds that show up can and will germinate on top of the fabric in settled dirt and organic matter.

3. Spray any weeds that still emerge anyway with herbicide.

Someday I will write a post, but it has been covered so broadly and thoroughly that I’m sure if you’re here, you already know that herbicides are not a good thing to be spraying in your yard or anywhere else. Organic or not, they all will negatively affect the soil, the soil life, and the ecosystem. Here’s a starter article.

4. Fertilize any plants that you do want there.

Fertilization through the decomposition of organic matter (mulch) is not an option with rock landscaping since the plant is surrounded by rock and landscape fabric, so you will need to fertilize the plants you have chosen to grow in this bed. Artificial fertilizer costs money and negatively affects, again, the soil, the soil life, and the greater ecosystems. Not to mention the entire watershed beneath you. Organic fertilizers like compost can be added, but, you will need to pull away the rock and landscape fabric to do it.

5. Haul organic matter away. 

When removing dead plant matter, you cannot chop and drop (and let the plant fertilize itself) because of the rock and barrier. You will need to haul that organic matter to the compost bin or vegetable garden. Unfortunately, most people don’t even keep this organic matter. They instead pay to have it removed.

6. Periodically remove and clean or replace landscape fabric and rock.

Seriously, I see this being done in my neighborhood on a regular basis. They usually hire it out. This is done because even if you remove all the weeds you killed and the dead matter from your plants, dirt and organic matter will still settle into the rocks and on top of the barrier. It will decompose and form a nice place for weeds to germinate above your barrier fabric. I think maybe they want it to be… cleaner, as well?

What to do instead

Rock mulch is really only low-maintenance for about a year. Thereafter, it is a nightmare unless you have no squabbles with regular use of herbicides and spending a pile of money on regular maintenance.

I recommend organic mulch. Any kind of organic mulch will do. Wood is king, especially in windy areas, but you can also use any dead plant matter you can find. And yes, you need to replace wood mulch if you are still wanting to go for the landscaping look that is mulch with a few landscaping plants scattered about. You will also still need to deal with weeds in sunny areas. I suggest letting go of the idea of this kind of landscaping. 

Rock mulch is high maintenance, but so is any kind of spaced out garden
This kind of garden with sporadic plants within unshaded mulch will still invite copious weeds.

The only way to combat weeds without constant pulling or spraying is the use of shade and filled niches. You can utilize the shade of trees, structures, or thickly planted plants. I suggest using them all in conjunction. Shady areas have their struggles with weeds too (like garlic mustard and buckthorn). So you also need to fill niches and utilize layers. Grow plants like they would grow in nature, where they occupy every niche in time (throughout the growing season) and space (low, middle, high, higher, and every inch of ground). Weeds like full sun and space to grow. Don’t provide them those and you won’t really have to worry about weeds much. Trees and thickly planted plants will also continue to mulch themselves once established, and so you will not have to continue to replace mulch. Just leave the leaves of trees or chop and drop the plants.

Rock mulch is high maintenance. Chop-and-drop mulching and thick planting is low maintenance.
Thickly planting and adding trees, then chop-and-drop mulching and leaving the leaves every year is the cheapest, easiest, and most low-maintenance way to garden. Skip the rock mulch and choose living mulch like this.

But what about termites?

Many homeowners are under the impression that rock mulch is better to have against the house than wood mulch if they have had termite problems in the past or if termites are a known problem in their area. The answer to that is: not necessarily.

In regards to landscaping against the house and termites, the relationship between mulch and termites entering the home is the moist, shady environment it provides. They don’t like heat or sun or dry conditions nor being exposed to predators, so if they have a safe passageway to the house and they deem the house to be a good place to colonize, they’ll take that as a passage. This actually applies to rock landscaping as well (they would travel under the fabric barrier), but rock mulch would be a little warmer and a little less wonderful than wood mulch. However, they don’t actually eat the wood mulch, and it is not for that reason that rock mulch is better suited to termite-prone areas.

The general advice is to keep a strip of bare soil about a food wide between landscaping and the house. But you know what bare soil does… it invites weeds. It would be even harder to maintain without herbicides than rock mulch. You could leave that strip as rock mulch if you’re very concerned about termites. Or you could consider planting highly aromatic plants in that bare strip, especially catnip and perennial onions like garlic, chive, garlic chive, and green onion. These plants may help to repel termites and rodents (peppermint especially repels rodents). 

I’m not a termite expert, but I would not surround my house with rock landscaping just to keep termites out. Hauling tons of rocks to homes for mulch is a relatively new thing in history, and before we started doing that, we weren’t losing all of our homes to termites within a couple years. 

In conclusion

Just don’t do it. Please, for the love of all that is holy and natural, do not purposely import and lay landscaping rock on your property. But if you decide to ignore me and do it anyway, hit me up. You can have all the rock piled up the north side of my house for free! You haul.