Rock Garden?

[Dog Rose]

We're trying to salvage a bed that has gone completely to weeds. It is completely overgrown, and when we cleared it we found tree roots close to the surface that make digging down impossible. Since it is in a hollow, with a rise in the ground by it, we were wondering about putting in a rock garden, but we're a little concerned about the weeds and ivy overgrowing whatever we put there.

Do you have any advice on building a rock garden from scratch and preventing it getting overrun? Obviously, we'd want it to be stable, since people and pets always climb on these things, but otherwise we're not sure what to put there. There's a large tree near it, but the roots have grown downwards from the bed so it shouldn't be too disruptive to the rocks.

 

[Owdboggy]

Alpine plants do not normally do well in competition with tree roots. So unless you can remove all of the roots and put some sort of barrier between the trees and the rock garden, then you are not going to have much success.
You could turn it into a fernery though, as long as it is not too sunny and grow the kind of woodland bulbs and plants which normally grow amongst tree roots.

 

[remnant]

It is not hard to show a weed free rock garden. Select an area with no manholes or underground pipes and clear the site of plants, growth and used roots. Construct a good drainage by removing a few inches of topsoil and mix with inches of gravel, rubble and coarse sand. Lay used resistant fabric on the ground to prevent weed growth but will allow water to penetrate.

 

[toradrake]

What about using the roots as a decoration for the rock garden? Put the rocks around the roots but do not cover them, then plant (sparsely) plants around the rock garden that do well near trees or that do not require lots of water (cactus type plants). I think it would look really nice and interesting.

 

[mgmine]

If you completely kill the weeds off you will get rid of the original problem. Normally you would use a product like Round Up, but with the tree roots you may want to be a little careful. You could kill the weeds off a little slower by covering them with newspaper. The other thing to consider is whether or not you will be completely covering the area with rocks. If so then the weeds will be taken care of. Simply cut them off at the ground with a weed wacker and that will be that. Add rocks, garden soil from a bag and plants. If you aren't planting seeds then Preem would be a good product to keep any new weeds from growing.

 

[Owdboggy]

Sorry, but covering persistent rooted weeds, like say Dandelions or Ground Elder or any which regrows from roots left in the ground is counter-productive. They will not be killed by covering with rocks. they will just be harder to remove in future when they grow. Indeed they are not killed by weed suppressing fabric either. They just push their way through it and are then harder to remove. Been there done that!
Round-up only affects green leaves, so any which touches tree roots would do no harm.

 

[mgmine]

Sorry but I have to disagree to everything except the weed suppressing fabric comment. Certain weeds such as wild onion can and do come through weed fabric that is why I recommended newspaper. When put down thick enough nothing will get through it. Weeds need sun to grow and without sun they will not grow. Weeds can easily be smothered with either paper or black plastic (not clear plastic). Weeds can also be smothered with rocks. To verify this move a rock and see if anything is growing under it. I am not talking about gravel like on a drive way I am talking about rocks like in a rock garden. As far as Roundup not hurting trees that is not correct. Here is just one of many articles pointing out the danger to trees.
http://homeguides.sfgate.com/effect-glyphosate-tree-roots-29076.html

 

[kgord]

I have a little rock garden in front of one of my trees. I really like it and add to it as I am able. I just picked a bare patch and use the garden as a bit of landscaping around a tall fully rooted tree. Ideally, I would like to add maybe 5 more large stones..so it is noticeable. I mean I know it is there, but I am not sure others would, if they weren't looking for it.