I got your email, Louise - Sorry, I've been away at a bonsai show & visiting friends/family. This is a tough one. As I understand it, you have a concrete block planter constructed atop a concrete slab, with no way for the water to make its way into the sand below the slab. Drilling holes in the block walls won't improve drainage. The only 2 ways to effectively improve drainage would be to make sure there is a 'bridge' between the soil in the planter and the sand below the concrete so the water can percolate through the soil, or to make sure the soil you use is porous enough that it holds little or no perched water. This would mean that your soil particles would have to be large & stable, insofar as their structure is concerned. Even the soil you see me holding above would be inappropriate for your application because that soil depends on the wicking action of the earth (in RBs) to ensure it doesn't remain saturated after rain/watering. It looks great, but if you have high standards it would be a disaster in a container or in your app. I'm thinking that about an 80% fraction of a mix of all purpose sand and all purpose gravel and 10% each of pine bark fines and Michigan (reed/sedge) peat or good compost would probably be the direction I would head. In subsequent years, I think all you'll need to do is mulch with pine bark to keep the soil healthy. If expense isn't a major consideration, you could use Turface MVP as the base ingredient for your soil. Topsoil and fine sand just isn't going to drain w/o help. The alternative would be to remove the old soil and cut a hole in the slab so water can drain from the soil in the planter, but it would have to be a hole of considerable size - preferably at the lowest point on the planter's bottom. If you have pictures, it's possible that something else might be devised that will allow the water to move out of the soil via some sort of passive wicking mechanism that we/you could devise, but I'd have to see the application in order to envision the possibilities. There might be a way to employ a false bottom by placing FRP panel on top of cement blocks that are resting on the bottom & building it like a self-watering container in reverse - where you employ a wicking column of soil to REMOVE water instead of supplying it, but I don't know how far you want to chase the issue? ;-) AL

I guess I did ask my question without regard for why the stones were there or whether it was right that they should be, and perhaps on the LD forum it is right that that question would be raised. I didn't think about going to another forum because the question came from another thread here. I used the example of a raised bed in the middle of a lawn as an example of why this question might be of broad general interest, but as it happens that isn't what I'm doing. I am trying to create some topography, having a tiresomely flat yard, but at the foundation, not in the middle of the yard. Fortunately our porch is of masonry block and dirt can be piled against it. I am having to slope down to avoid putting dirt against either side of the wooden stairs, which abut the centre of the porch, so my raised bed is bound to be an imperfect design. But I want rocks, and I want relief from flatness, and I want a stepped rock garden, whether it constitutes good design in my setting or not! I was driving around the suburbs today noting the use of stone in yards both obviously professionally installed and maintained, and DIY. In one case gravel was the surface of choice outside the fairly large stones. In another case, someone had lovingly and optimistically ringed all the beds with quite small rocks, and was clearly losing the battle to keep the grass from growing between them. In yet another case, someone had installed - but not quite deep enough - plastic edging with the rolled top around another small rock edging, showing to just what dreadful extremes one can be driven by the frustration of grass invading rocks, or being unable to mow. It is perhaps surprising in these cases that the removal of the rocks is apparently not contemplated. I think it's a question worth asking in some cases, for reasons of either design OR maintenance. KarinL

Tuffatuffa AC noise has different frequencies. One of them being Humm, which typically transfers mechanically (making adjacent structures vibrate with them). Wood is typically used in combination with space, creating sound "traps" for lower frequencies (the humming part of your AC noise). Remember, higher frequencies have shorter wave lengths, so combining different density materials is what you're going for, unless there's a specific frequency range you want to address. This seems like a good link. Let me know if it doesn't answer your questions and I'll do some more research Bass trap I think you're looking for acoustic insulation that wont look bad. Since AC noise will have a variation of frequencies, the more diverse materials you use, the more diverse the frequencies you will absorb. Then, the higher frequencies will just be reflected by the solid surface of the tufa. So, this is how I would do it: 1) Make your wall with a frame of 2x4s for shape 2) Take a piece of plywood or something to go along the interior. Staple it 2 inches from the border (so you're in the middle of the wall). 3) Fill the remaining space (which should be about 2 inches on each side) with foam, carpet or whatever you can find and dispose of. 4) Use some kind of metal lathe to give the tufa something to cling to, and stable it to your wooden frame. 5) If you want to take it a step further, before covering with tuva, cut a few sections of PVC pipe and place it at even intervals accross the side of your wall (about an inch or two of separation). This will insure different frequencies are reflected in different directions 6) Cover the whole thing with tufa. Then, cover with plastic so you can isolate the foam from your wet tufa when you apply Now you have an effective bass(humm) trap, and high and mid frequency absorbtion and reflection (with the interior foam for absorbtion and the corrugated tufa surface for reflection) If you can, lie your "wall" on the floor when applying the tufa. Or at least at an angle so our tufa doesn't slide down. You'll find this is where the lathe will come in handy ;-) Forget my comment about replacing the AC. I have a noisy AC myself, so I am biased towards just dumping the thing :-) OK, I'm typing a lot and I don't know if I'm answering your questions. Let me know if there's anything else I can do to help.

To show visuals of Bab’s great ideas (and again, not knowing your exact growing conditions, just general ideas ... your local nurseries can best advise on specifics once you decide the look you’d like): With a pink color scheme you asked about. The hedge is dwarf Yaupon Holly, and they stay pretty compact on their own, if you don’t want a sheared look like this: No hedge (fountain grass):