I think this counts as container gardening...

Our outdoor space is sadly fairly small and all block paved.

I am looking to build a large wood planter and plonk it in the middle of the space, size will be around 2.1m x 2.1m and I was thinking 60cm high. In the middle will be a wooden box with a self-contained water feature sitting on top to give some movement etc

The planter will be made out of 100mm fence posts stacked/fixed and the top layer is to be 200mm wide to give seating all round. I calculate it will need 1 jumbo bag of gravel topped with 2 jumbos of soil.

Climate is fairly sheltered, it gets sun 3-4 hours a day in spring and more in summer, its 2m away from house on one side and there are fences on the other two side about 3m and 5m away, the last side is open.

My questions.....
1 - What sort of soil - i see there is "topsoil" and "garden soil" listed, what is correct for planting??

2 - Does 2/3 soil and 1/3 gravel seem about right, there is no base, the floor will be the block pavings?

3 - I was looking to line the inside with a black poly sheet to keep the soil mostly off the timber - sensible or not?

4 - We want colourful but fairly easy to maintain plantings - what sort of plants might we be looking at?

Thanks for any tips.

 

1...garden soil is topsoil enriched with compost, manure etc to make it more suitable for the garden. It will depend what you want to grow on what soil mixture you create.
2...again it depends what you want to grow on what your mix will be. I think I'd put 3" or 4" of gravel in the bottom to give you a bit of a soakaway.
3...I nearly always put dpm around the inside of mine I think it helps to preserve the wood.
4...better people than me to give you advice on plants, I just try and grow mainly for bees, bird's and butterflies.

 

Thanks, i was mostly looking at ready mixed "garden soil" - we have no soil here at all so it will all have to be bought in in dumpy bags

The area is 4sqm so its going to be tricky getting the gravel in a bulk bag as they seem to be about 0.8cum which is twice what i need if only going for a 4" layer. 16 x 25kg bags will do it though and its only small amount more expensive - better than having half a dumpy left on the drive

 

Finished building the planter today, a nice fun project. Waiting on gravel and soil now, then its off to the garden centre i guess

 

Nice job

 

450kg of 20mm gravel a depth of 100mm exactly as calculated

 

Hello! Now for the exciting part! The classic advice is to plan for foliage interest because that's there for much longer than the flowers. Go for a mix of colours, leaf shape and texture. Then the flowers are the icing on the cake. For contrasting foliage, there's Nandina domestica 'Firepower', Phormium cookianum hybrids (smaller than tenax), silvers like Lavender, Helichrysum, Santolina, Ballota, coloured-leaved Salvia officianalis (purple, yellow/green, green/white/pink), most flowering shrubs now have dwarf forms which is handy Then, for flowers, it will depend on your colour preferences. Blues, pinks, purples or oranges, reds and yellows....
As the soil is likely to be a neutral Ph value, best avoid Rhododendrons, Azaleas, Pieris, Kalmia etc., unless you want to be constantly treating the soil to make it acidic.