Thanks again folks - I started filling the bed today until rain stopped play later on - the topsoil I'm using is quite loose, and seems to have quite a bit of organic matter in it. so I don't think I'll need to add any compost. I've mixed this 50/50 with the grit, and I'm glad I asked on here to get some reassurance - had I tried this myself I would have thought the end result was way too gritty. You live and learn as they say...
I don't need to worry about the bed filling with water, as although it's made of blockwork, the blocks aren't bonded by cement, but rather some kind of glue/resin, and there are plenty of gaps holes all the way through. The result is more akin to a dry stone wall than typical brickwork.
It also depends on what you intend planting in it. It's a fair old height, and most plants don't need that depth of soil to grow well, so it's expensive to completely fill it with soil/compost etc, especially if you're buying it in. Perlite is a very expensive addition - it's usually for mixing in small pots or trays for seed sowing - you wouldn't add it to a permanent feature. Any old rubble for the bottom half is fine, or turf if that's available. I used all the turf I lifted, to put in the bottom of mine.
Grit wouldn't be necessary to top dress if it's a shrub or something like an Acer. Bark would be better. It's nice for spring bulbs or anything with flowers that easily get splashed by soil when it rains. That's the main reason I use it in pots, although any gravel is fine
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
The construction and topsoil sound good. I read your other thread after replying to this one, I see you already have rubble in the bottom, so sounds like your all sorted. Grit as a topper/mulch will eventually end up sinking and merging with the soil, especially after heavy rain. It does look good with med plants tho and at least you easily mix it with more soil/compost if the levels drop and top off again.
Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
I have a sandstone blockwork planter I'm just about to fill for sun loving plants. I've been building the soil level so that it is now about 10-12cm from the rim - what would you suggest for the ideal final fill level - how far below the rim is the best balance?
I don't want to lose soil etc overboard onto the patio, but I also don't want excessive shading by the planter walls. It's also in a pretty exposed location close to the coast, and approx. 1 metre high.
50mm is the standard from lip to finished soil level. Make sure its well compacted but not too firm.
Good stuff, lots of useful info. I didn't consider the grit sinking ino the bed..hmmm.. I was going to use the RHS branded bags of grit I spotted in Dobbies - this grit seems a lot more colourful and interesting than 'standard' grit, but of course there's a premium to be paid, and if it's going to eventually disappear into the bed, I may well rethink that one..
You could use bog standard pea gravel if it's only to assist drainage throughout the container. If you had placed a layer of landscape fabric or something similar, over the bulk in the bottom half, that also helps prevent the soil mix sinking through it all. Then you only need a suitable medium in around the top foot or so, or even less. I didn't realise you had another thread - what plants are you growing? Is it sun loving types?
B&Q also sells grit. It isn't too expensive in there. I put it in a container with holes in the bottom and a bit of fine mesh, then, I either rinse it manually, or the rain washes out any manky stuff so that it's nice and fresh for anything I want it for. I only use it for top dressing or for soil mixes for seed sowing ,or in smaller pots etc. I wouldn't be using loads of it to help with drainage in such a deep container.
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
Almost all finished now - I had stocked up on grit from B&Q at the weekend, and mixed it 50/50 with bags of Westland topsoil. Interestingly, because I had bought the Perlite in bulk - 100 litre bags - it worked out much cheaper than the grit. Just got the fancy topping of girt to do now, and then add the herbs etc. I had intended to start planting at the weekend but now I see there's another cold snap on the way...
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Any old rubble for the bottom half is fine, or turf if that's available. I used all the turf I lifted, to put in the bottom of mine.
Grit wouldn't be necessary to top dress if it's a shrub or something like an Acer. Bark would be better. It's nice for spring bulbs or anything with flowers that easily get splashed by soil when it rains. That's the main reason I use it in pots, although any gravel is fine
I live in west central Scotland - not where that photo is...
I didn't realise you had another thread - what plants are you growing? Is it sun loving types?
B&Q also sells grit. It isn't too expensive in there. I put it in a container with holes in the bottom and a bit of fine mesh, then, I either rinse it manually, or the rain washes out any manky stuff so that it's nice and fresh for anything I want it for.
I only use it for top dressing or for soil mixes for seed sowing ,or in smaller pots etc. I wouldn't be using loads of it to help with drainage in such a deep container.
I live in west central Scotland - not where that photo is...