Home -> Small Garden Landscape -> Small Garden Landscape Design -> Best way to separate dirt from decorative rocks?

Best way to separate dirt from decorative rocks?

This is in a small landscaping rock garden. The small rocks are on a 15' long & 2' wide galvanized sheet metal channel designed to direct water quickly to a front yard storm drain (or else our basement would flood). I'll need to remove the rocks & grit by hand but it's a small job. Grit from the driveway and dirt has caused the channel to fill up. What's the best way to separate the grit/dirt from the rocks? What can I use that would function in effect as a colander? Thanks.


  1. fire
  2. wash them with water
  3. Nearly impossible. Sorry, I have done this in different ways and a powerwasher was my only solution. However, I displaced many rocks. More work upon more work. UGH!
  4. Let it dry thoroughly and use a leaf blower to blast the dirt out of the rocks.
  5. Build a screed for this job. You'll need about 4x4 feet of 1/2" hardware cloth and some 2x4 lumber, Build a square frame, that is elevated at one end, nail the cloth to the frame, shovel the material on to the cloth and let gravity do the work. the dirt should fall through the cloth and leave you with rocks about 1/2" and larger to put back in your trough. Once you get it cleaned out, you might consider a settling area near the storm drain to catch the dirt before it gets to the drain that can be easily emptied with a shovel. As long as this dirt has no oil in it, it can be mixed with good topsoil and used for a garden.
  6. I had a path made of small stones that filled up with soil. I scooped them out and set them on the drive way and then blasted them with a hose sprayer. It washed the dirt away and left the stones nice and clean. I scooped them back up and put them back in the walk. You might want to try using this technique if you have someplace to blast the stones with a hose sprayer where the soil can be washed away.
  7. Pick up and move all the rocks. remove and discard smaller stuff. replace rocks.
  8. I'm running into the same problem but with a much bigger rock bed and bigger rocks. I do not have sheet metal lining the rock bed, just smaller rocks at the botton and bigger rocks on top. But the function of my rock bed is more as a retention basin until the soil can absorb the water. Anyway, I think the key for you is to do what others suggested and either make a screen to screen out the dirt or blow it out with a blower. I screened gravel once before and it's a tedious task, but works well. The leaf blower may or may not work for you. It all depends on the power of the leaf blower and the size of your rocks. If the leaf blower is too powerful, it'll also blow your rocks out of the rock bed. I have a real problem with this. My electric leaf blower has two speeds: turbo and super turbo. I also have a battery operated one, but it has pretty weak power and is more of a sweeper. If you go this route, I'd rake the rocks a few times before you blow them (if they are small enough) to loosen as much dirt as possible. I think a way to help prevent this in the future is to ensure that you've got clean rock in the river bed. If you end up screening the dirt out, I'd lay out the rock on your driveway or something and spray it down with water and dry before you put it back. This will get any remaining sand and fine grit off the rocks. Also, if the rock bed is on a downhill grade, you may want to occassionally spray it down with a power hose nozzle or a pressure washer, forcing the dirt downhill and out of the rock bed, before it gets too clogged up.