Rocks instead of mulch

[Sabina515]

Hi everyone!

Im in zone 5. I am at the point where I am getting spent on weeding lol. Most of the mulch has blown away or decomposed. Or the other areas that I didn't mulch this year. I have a fairly large area of everything that requires alot of mulch. I was thinking to use rocks in some areas. Thoughts?

Lava rock for 15 rose bushes. This area gets sun all day. I read this is is ok as it doesn't increase heat like other rocks but retains moisture.
River Rock for all the hostas lined up on north side of house that sit in shade.
River rock for the front that has mostly shrubs and sun goes away and turns to shade around 2pm

Flower beds i will use mulch.

 

[Marck]

I try to mulch my beds thoroughly. In different areas I have used fine leaf mulches, bark, wood chips, and several different types of rock. I agree that the porousness of lava rock can be an added benefit.

In each area, I'm trying to balance my desire for the relative permanency of the rock with the added moisture retention and soil-building benefits of the organic material. Bark or wood chips is often a nice compromise between the two.

Also, in some areas, I have actually mulched with a blend of bark and pebbles because I wanted to split the difference between the benefits of the two materials.

Replacing organic mulches is added labor, but raking or removing rock when replanting is also extra labor.

Of course some weeds come through any mulch. The thickness of the mulch can reduce this, as can putting down layers of cardboard, which I only do if weed prevention is the main issue. Personally, I am opposed to plastic weed cloth, but I know it is commonly used by others.

 

[Sabina515]

Thanks! My goal is to not replace of course any! Lol. My plan was to add the rocks next year, and I know weeds still pop through but not as much. I added a thick layer of mulch down but wondering where it all went lol. So you think if I mix lava rock with mulch on the roses it will be ok? If so then I can do this in the other spots.. I dont plan on removing any mulch, just tossing the rocks on top.

 

[Marck]

Yes, overall it will be fine, rock is frequently used as a mulch, but organic mulch also serves an additional benefit in improving the soil texture and microbial health of your soil. Organic mulch does breakdown, but during that process it adds nutrients and supplies food and habitat to the microfauna in the soil.

For most mesic (average water use) plantings, I prefer using compost or wood mulch and fine to medium bark, even though replacing organic mulches is additional labor.

 

[Mr_Yan]

Rocks are a terrible idea unless you put a TON of work into it. I'm dealing with the aftermath of the owners before me mulching with rocks.

These work into the soil then make it nearly impossible to dig in later.

Through root growth, worm activity, decomposing leaf litter, and walking on then the rocks will work down into the ground and the soil will cover what you put down.

If you want rock / gravel paths make them like you would a slightly lazy paver path. Dig down, remove most of the top soil, define the edge, add a heavy weed barrier, then pour rock a few inches thick over that.

 

[Jewell]

Rocks are a terrible idea unless you put a TON of work into it. I'm dealing with the aftermath of the owners before me mulching with rocks.

These work into the soil then make it nearly impossible to dig in later.

Through root growth, worm activity, decomposing leaf litter, and walking on then the rocks will work down into the ground and the soil will cover what you put down.

If you want rock / gravel paths make them like you would a slightly lazy paver path. Dig down, remove most of the top soil, define the edge, add a heavy weed barrier, then pour rock a few inches thick over that.

Totally agree. Rocks never end well and after a few years nature will plant an abundance of weeds in the rocks. Nature always wins when attempting to change the natural conditions. Unless you have a dry creek bed with a foundation of layers and layers of sand mulch is the best method. Mulch also has the added benefit of making it easy to expand, shrink, or do away with a bed easily. There is also the hazard of a rock or two getting misplaced into lawn. The neighbor broke one of our car windows with “decorative “ lava rock turned missal in the mower, but fortunately didn’t hurt any human.

 

[lifegardener]

Rocks (and smaller stones), when used correctly, can be an excellent long-term mulch. Personally, works great around vegetation that will remain fixed over the years.

 

[Esther Knapicius]

Rocks absorb heat then reflect it back to the plant causing the plant to get too hot and dry out. I would not use rocks anywhere near any of my plants. Mulch is a better. I rarely use mulch now. my gardens are dense, only minor weed pulling of thin grass stuff is necessary as I roam about with my coffee in one hand.

 

[Marck]

I agree that the benefits of organic mulch make it the best mulch to use in most situations. However I do use rocks or a blend of rock/coarse sand and organic mater in certain situations.

Rocks can be helpful to add additional stability or drainage at a plant's crown. Rocks mulches can also discourage animal-digging.

Of course many rock gardeners and desert landscapers oten choose a rock mulch. At the same time, these gardeners often need to find ways to incorporate some additional organic matter into their soils as well. As always, 'balance' is key.

 

[Oliver Buckle]

I expect everyone is getting used to me saying how I burn clay to terracotta by now. I have a bed I had cleared of a horrid bit of hedge, a useless shrub and a lot of weeds and brambles. hen I dug it over it was nearly all clay and today I put a large barrow full of terracotta back into it. I sieved what I had and have a lot of larger pieces left over, I was thinking of burying them as a soak away where I get flooding, but you have me thinking I might use them as a mulch. If they get worked into the soil it won't matter too much, they will break down as I hoe/dig, and they are permeable like your lava rock, thanks for the thought.
Take note of Mr Yan's post, I can see they might easily be a pain in many cases, but something permeable and size degradable I can see as adding to the soil in the long term.

 

[Winifred]

Thanks! My goal is to not replace of course any! Lol. My plan was to add the rocks next year, and I know weeds still pop through but not as much. I added a thick layer of mulch down but wondering where it all went lol. So you think if I mix lava rock with mulch on the roses it will be ok? If so then I can do this in the other spots.. I dont plan on removing any mulch, just tossing the rocks on top.

 

[Winifred]

I have beds where previous owners just threw down rock as mulch. Nightmare! I'm in zone 5 also and don't like to mulch or weed. I've been working on putting ground covers down between all my plants. Problem solved.

 

[CJSIMS]

Yes, overall it will be fine, rock is frequently used as a mulch, but organic mulch also serves an additional benefit in improving the soil texture and microbial health of your soil. Organic mulch does breakdown, but during that process it adds nutrients and supplies food and habitat to the microfauna in the soil.

For most mesic (average water use) plantings, I prefer using compost or wood mulch and fine to medium bark, even though replacing organic mulches is additional labor.

Do we need to always remove the mulch from the previous season or can we mix it up a little with the soil, plant the new flowers and put down fresh mulch?

 

[Marck]

Do we need to always remove the mulch from the previous season or can we mix it up a little with the soil, plant the new flowers and put down fresh mulch?

No, don't remove it. Just leave the old mulch (or mix it in when planting) and apply new mulch on top. All organic mulch will breakdown with time, but nutrients, humic compounds, and other benefits will remain.

 

[DirtMechanic]

I expect everyone is getting used to me saying how I burn clay to terracotta by now. I have a bed I had cleared of a horrid bit of hedge, a useless shrub and a lot of weeds and brambles. hen I dug it over it was nearly all clay and today I put a large barrow full of terracotta back into it. I sieved what I had and have a lot of larger pieces left over, I was thinking of burying them as a soak away where I get flooding, but you have me thinking I might use them as a mulch. If they get worked into the soil it won't matter too much, they will break down as I hoe/dig, and they are permeable like your lava rock, thanks for the thought.
Take note of Mr Yan's post, I can see they might easily be a pain in many cases, but something permeable and size degradable I can see as adding to the soil in the long term.

Baked clay products like turface are not far at all from your terra cotta.

I find larger stones help retain moisture. Large, like a step stone. I have no use for impermeable stone. It act likeva bunch of glass beads, which I would find more interesting visually, I suspect.