Is Compost enough or do I need topsoil too

So I am working on a top section of my garden (on top of a wall) and I want to landscape with shrubs, plants and bulbs.

My, rather naive, question is can I fill the area with bags of compost and brown gold or should I add a layer of topsoil first?


I am creating a section with garden edging to clearly separate the sloping section to the fencing and the area where I would like to plant shrubs etc see photos below

I was, naively, going to just fill with bags of compost and brown gold soil enricher but I think that is not enough for the plants to establish themselves.


Please let me know.

 

I think you need topsoil, it could even work out cheaper.
Compost would tend to disappear after a couple of years and you would need to keep topping it up.
I'd be inclined to break up what is already there, to some extent, and then get some bulk bags of topsoil.

 

Thanks for the reply bulk bags of top soil are an option though they only willing to deliver one tonne bulk bags or more for bout €110-€120 - I don’t think I need one tonne for the area I am currently working so the other option is 35l bags of topsoil - one business is offering 3 for €15 so I could get delivered about 20 bags for bout €90 with free as the order would be over €60. I would then mix the topsoil with the bags of compost I purchased already

 

I think you're underestimating how much you need. If it's to fill the trench in the second picture, I reckon it'll just swallow up a tonne of topsoil and leave you wondering where it all went.

Most bulk suppliers have an online calculator where you can specify the length, width and depth and it will tell you how many tonnes you'll need.

I wouldn't go with compost alone. It will be a maintenance nightmare because compost alone doesn't hold nutrients that well, and it will dry out super fast.

 

Its a difficult shape to work out how much you will need, but as Clueless says once you start spreading it around its surprising where it all goes.
It will settle to some extent as well.

 

I would mix top soil with compost or just use john innes compost and mix in the odd bag of multi-purpose. Why not just get a few bags of top soil or john innes and see how far it goes, then you can calculate how much more you need. Top soil in general is 600L to the ton, that's when it is 100% soil. Nowadays it tends to blended with organic and green waste to bulk it up, whether it is sold in bulk bags or 35l bags.

 

I wouldn't use John Innes at the price it is around here.

 

Thanks for the replies fellow gardeners so first and foremost I need topsoil compost and ‘brown gold’ ain’t enough
and yes John Innes is expensive here too!!

The site I am working with is arkward (sp??) and I am finding it hard to judge how much material is needed - I do have a sizeable amount of compost in 35 litre bags about 8 of these and 4 mini bales of brown gold soil enricher each of these 70 litres. So perhaps 35litre bags of top soil (about 20 -25 in total) would suffice but as pointed out in replies there will be settling too

 

I think the crux of the matter is go for something with soil as all this organic material rots away and disappears over a couple of years.

 

Morning all,

So yesterday I brought in bagged top spoil for the area on the wall and along with bags of compost I have prepared the beds on the top wall

What do you think?

 

Another pic

 

Almost a year later but thought some fellow gardeners might like to see the latest state of this area!!

Let me know what ye think

 

It's come on a treat Will. May I suggest planting something more colourful against the fencing, perhaps climbers, to lighten the area?

 

The heuchera is living its best life

 

Thanks for the compliment, not a big lover of climbers especially on fences and more sore when it isn't mine!

The slope, though narrow, is quite steep so I kind of have a no-mans land there with weed suppressant