Mulch vs Rock vs Soil: What’s Best For My Planter Beds?


Once your great new plants are in the ground, brightening up your landscape, it’s time to decide the finishing touch — what goes on top?

Mulch? Rocks? Or keep it simple with a top dressing of soil?

Let’s take a look at mulch vs rock vs soil for planter beds and see how it all shakes out.

A Look At Mulch


Gardeners love mulch. Shredded bark is the king of mulch, either natural or dyed a dark brown for a rich look.

Plant bed with mulch

For such a simple material, mulch has a lot of benefits for planter beds.

The Pros of Mulch:

  • Bark mulch conserves water, by holding in your soil’s moisture so you need less irrigation.
  • It protects your plants’ roots from extremes in temperature, keeping them cozy in cold weather and cool in summer’s heat.
  • Mulch keeps rain from washing away your soil.
  • As it decomposes over time, bark mulch adds nutrients to your soil.
  • And, maybe everybody’s favorite mulch benefit: it discourages weeds from popping up, keeping everything dark so the weed seeds can’t sprout.
  • Finally, mulch just looks great, adding a tidy, uniform appearance to your beds.

The Cons of Mulch:

  • Shredded bark mulch can blow away if you have windy conditions on your property.
  • It doesn’t last forever. You have to replace it every couple seasons.

The Average Cost of Mulch: $40-$50 per yard, not including delivery or installation.

Decorative Rock Mulch


A top dressing of rock is a good choice if your bed isn’t filled with plants, or if drainage is your main concern.

Plant beds with rock mulch

The Pros of Rock Mulch:

  • Rock stays put. This is a plus if you have a lot of wind, and your shredded bark keeps blowing away with every big gust. And, you don’t have to reapply it every season or two.
  • Rock creates great drainage, if you have excess water issues on your property.

The Cons of Rock Mulch:

  • Rock doesn’t add any nutrients to your soil, because it doesn’t break down over time.
  • If you change your mind later, and want to add more plants and turn the space into a real garden bed, it’s kind of a pain to remove all the rock.

The Cost of Rock Mulch: Basic, non-decorative rock runs $12 to $15 per yard before installation or delivery.

But if you want more attractive, decorative rock, the price jumps sharply. The pretty black and tan rocks cost $80 to $110 per yard.

That’s pretty pricey. But if you’ve replenished bark mulch more times than you can count because the wind blows it away, it might be worth the investment.

Soil for Planter Beds

When you consider mulch vs rock vs soil, it’s tempting to just choose soil. It’s already there, right? What could be easier? But there are some disadvantages.

The Pros of Soil for Plant Beds:

  • There’s no extra cost to just leave your beds bare.

The Cons of Soil for Plant Beds:

  • Bare soil dries out quickly in the sun and wind, leaving your plants thirsty for water.
  • Rain can easily wash soil away, exposing your plants’ roots to scorching sun, drying winds and icy blasts.
  • Weeds will have a field day, because there’s nothing to keep them from happily sprouting and growing.
  • Soil doesn’t look as neat or attractive as a more polished dressing of bark mulch or rock.

A Quick Word About Playground Mulch


If your property includes a playground, choose mulch designed specifically for play surfaces that will keep the kids safe. Opt for clean wood with smooth edges or recycled tire mulch. This will prevent slivers.

Perplexed About Mulch vs Rock vs Soil? Give Outback A Call


We know a lot about mulch. It’s part of what we do every day.

We’re happy to take a look at your property and help you decide what type is best for your beds.

We’ll even spread it for you. This day keeps getting better!

Located in Idaho Falls, Idaho, we serve residential and commercial properties in Idaho Falls, Rexburg and Pocatello, Idaho, as well as Bonneville, Madison and Bannock counties.

Contact Outback Landscape at 208-656-3220, or fill out the contact form to schedule a free consultation.

We’d love to hear from you.

Get Started