Gravel or coarse sand added to an entire planting area can help to improve drainage because it introduces spaces in between the soil particles for water to penetrate, but it takes quite a lot to have much of an effect. And it needs to be fully incorporated into the soil to a significant depth, not applied as a layer. The accepted horticultural convention is that organic matter (i.e. compost) is preferred for this purpose, as its decomposition over time improves soil fertility and structure in addition to increasing the pore space. The incorporation of the gravel or compost into the entire planting area is the same theory behind not amending individual planting holes - amending creates situations of different soil structure adjacent to each other - this impedes root development as well as water penetration. It's called soil interface issues and if your "landscaper" is self-taught or long out of school, he may not be familiar with the both the theory and the current practices. Establishing a border of drain rock at the front base of the wall where it meets the lawn (or whatever) should help to reduce the wading pool effect. It is a pretty common application here with heavy, poorly draining NW soils and if deep and wide enough, relatively effective. It can even have the appearance of a dry stream bed (or mostly dry) and become part of the garden aesthetic as well as being a highly functional application.

I plant almost exclusively in these unenclosed raised beds. I call them berms but not sure if that's the appropriate term for them. Some of them I have simply laid down a layer of cardboard to smother out the weeds in that area and then piled topsoil roughly 1 foot high with it decreasing to ground level gradually at the edges. I planted shallow-rooted perennials, herbs & veggies in these beds. Some of my beds though I decided to go ahead and till up the ground below and then add the soil berm on top. Do this for deeper rooted shrubs/trees, roses, etc... Plant your plants and then top with a layer of mulch. I've had no problem with rain washing away any of the berms but then again they weren't in areas where there was alot of washout anyway. Just pack it down gently with your foot and it should stay put. If it is in a washout prone spot you may need to re-direct the runoff with a ditch, some corrugated drainage pipe and gravel. Good luck with your project! Danielle

The ph and complete composition of mushroom compost is going to depend on what the mushroom growers use to make their compost and what they add to it. This will likely vary depending on what type of mushrooms are being grown. The mushroom farm where I get my compost uses gypsum for added calcium so I don't expect that the pH of mine is exceptionally high. The soil the OP has sounds like it is at least on the slightly acidic side (strawberrys mentioned.) And another component of the raised bed mix is peat so I doubt the problems in the raised bed are due to High pH. The manure/Mushroom compost mix may have a fair amount of nitrogen but if it was sterilized before being sold, then it may not have the necessary microbes in it to make the nitrogen available to the plants. Softmentor, your lengthy post about how plants and seeds can't grow in the non mineral soil media, I can't agree with. I have grown plants hydroponically and Therefore know that soil is not necessary. That said, most of my gardening is outside on the ground, the larger deeper rooted plants I'm sure reach the native soil, but a huge number of my plants are actually growing in deep layers of mulch and compost. I've found seedlings sprouting in 4' deep piles of wood chips before so saying that "Seeds can't grow in the "O" horizon, they need to be in the "A" horizon" just doesn't jive with what I have observed in my gardening nor in nature. Some seeds/plants may need the mineral soil more than others but most any plant you can grow in a container with a potting mix can grow without mineral soil provided it gets fertilized with what it needs.

GG: Concrete, while not completely impervious to water, will greatly impede the flow of water. Depending on the type of concrete, water can pool on concrete for many hours and days. And whenever a soil mix encounters a material of different water flow characteristics it will support a PWT. For PWT it does not matter whether water can seep out of the sides of the container or not. PWt is purely a vertical phenomenon. If the sides are open to air then there will be just be a layer of dry soil at the boundary. The only thing that matters is what is beneath the soil mix. In this case concrete will act like a barrier to water flow downwards. As long as it impedes the downward flow of water the soil above will act like it is in a container. Same thing will happen if one digs into very hard impervious clay to plant in ground. It will act like a container. Underground aquifers are formed this way - very porous rock sitting on top of impervious rock. Technically, that is where the name perched water originally comes from (geo-science)