Soil that's been buried under concrete?

CuppaCocoa

As part of our house renovation our builders will be removing a large concrete slab underneath the sitting room window. I want to plant bushes here but want to know whether I should dig out the existing soil underneath the concrete and get rid of it and replace it with fresh or aerate what's there and plant away . The concrete is about 3ft x 6ft and has been there for over 40 years!

looksee

Maybe wait and see what is under there. Chances are it is rubble and rubbish. Once the slab has gone I think you will find it will need to be topped up to get any sort of reasonable level. If by chance you find there is soil under it, then dig it over and improve with something like compost, but I think that is a bit unlikely.

Sonnenblumen

You might be surprised to find that the soil might perhaps be very useable (builders were better once upon a time). Anyways remove any debris and supplement soil with a few bags of well rotted farmyard manure and add some peat free compost. You can purchase very good quality manure in small bags at your local garden centre/shop. Fork it in well and allow area to settle for a small time before planting.

magicbastarder

i did something similar (in phibsboro) with a section of a yard which was probably under concrete at least 20 years.
i had to lift out a lot of junk, but the soil itself was very good; i had to top it up with topsoil sourced elsewhere though, just to bring the level up.

CuppaCocoa

Thanks for the advice! Look forward to seeing what's under the slab!

CuppaCocoa

Update! The soil isn't bad at all, only problem is it's full of stones and slate. Took me ages to dig out a hole big enough to plant a magnolia bush in the other day. I've a hell of a lot more digging to do though

Next question - the strip of ground under the window is about 3 feet wide and runs along the width of the house to the hall door. I want to plant some small bushes, preferably ones that are evergreen. The rest of the garden has raised planter boxes made from railway sleepers on two sides and the middle of the garden is covered in stone chippings. It's an old Victorian house with a lovely tiled path and I want something attractive yet not too tall that will be in keeping with the house (the stones were there when we bought it )

Can anyone recommend any plants/bushes?

Sonnenblumen

Great to see you're making good progress. For a very formal look, you might consider Buxus Sempervirens, but if you do not like the clipped look try the fabulous Sarcococca Confusa.

For a more simple natural but ornamental look, consider the stunning Euphorbia amygdaloides 'Robbiae'.

Tip: add some ericaceous compost to the soil around your newly planted Magnolia.;)

CuppaCocoa

Thanks! I put some top soil into the hole when I planted the Magnolia.

bmaxi

lilybarlean wrote: »

Thanks! I put some top soil into the hole when I planted the Magnolia.

As Sonnemblomen has said magnolias need an acid soil. What type of magnolia did you plant under a window? Magnolias, with the exception of Stellata, can grow quite big. They also don't like being dry at the roots and wouldn't appreciate being too close to a wall which would suck moisture from the soil, water it well and give it mulch of peat.

moceri

Be careful when planting so close to your external wall. If the soil is above the damp course then you may have damp/water ingress making the wall damp. Watering plants so close to the wall may also cause water splash making the wall damp.
Have you considered how big a magnolia will grow? Dwarf azaleas may be a better choice if the site is in shade. Carpet roses make a nice display for a Sunny site.