Depth of soil when using a builders bag

[rary]

i intend to use builders bags making raised beds, and would like to know what would be the recommendation for minimum depth would be

[Small pumpkin]

I'd probably go with minimum of 12" .
But if you can make a frame for the bag, I'd fill it to the top. So you can save the knees and back when you're weeding, planting and harvesting.

[Bill Door]

Without sounding silly I would say as much as you can get in.

For instance if you are growing a salad crop first then you could get away with about a foot (that is provide you can stop the sides flopping in). Beetroot and chard would require more , say two feet. But don't forget they don't like it rich.

If you are first growing root crops (carrots, parsnips or herbs) you may need at least two feet.

Potatoes you should start with six inches and then add more soil/compost as the potatoes grow.

Some crops like rhubarb and courgettes like well fed soil.

Don't forget that some crops (cabbage family) don't like too rich a soil.

So I would say that once you know what you are going to grow then you can decide how little soil/compost you will need. Personally if I had 10 builders bags I would fill them with 60% soil; 10% sand and 30% compost and grow any crop except cabbage. For next year I would trial a four year rotation.

Good luck

Bill

[veggiechicken]

I put stakes outside at each corner and looped the handles onto them. This stopped the sides from bulging out. Just a thought

[burnie]

Be aware the do perish and you will get holes in them, they are not a permanent solution.

[alldigging]

I've used one this year. I gave a builders bag to someone for their weeds and they decided they didn't want the weeds. So they put it on my plot and I put a layer of muck on the top and put a courgette in. It's done really well. It'll all be emptied out in the next few weeks and we'll see how much of the weeds have rotted down.

[rary]

Be aware the do perish and you will get holes in them, they are not a permanent solution.

How long would you reckon they would last for?

[ESBkevin]

As burnie says they do succumb to the effects of UV damage and break down. You can then end up with countless strands of varying lengths of plastic contaminating the plot.
I think you would be good for 2-3 years before some notable degradation occures. If you can replace them every couple of years you'd be good but thats a lot of filling and emptying in between.

[burnie]

When you consider they are designed to lift a tonne of weight, you'd think they would be fairly robust, my experience shows not so. I've stored logs, covered bikes/old wheel barrows etc and I reckon no more than 2 years before they start to show signs they're breaking up.

[Potstubsdustbins]

Being as tight as a duck's watsit I grow everything except spuds in containers 6 to 14 inches deep, never found any need to go deeper.

[no_akira]

I tried the other year and it was a complete "fail" unfortunately, the soil kept drying out. Might have been better if i'd cut the bottom out. The size of the bags encourages you to fill with too much soil.

[Cadalot]

I tried the other year and it was a complete "fail" unfortunately, the soil kept drying out. Might have been better if i'd cut the bottom out. The size of the bags encourages you to fill with too much soil.

If you cut them they will fray and unravel best to roll of fold them down

[sparrow100]

When you consider they are designed to lift a tonne of weight, you'd think they would be fairly robust, my experience shows not so. I've stored logs, covered bikes/old wheel barrows etc and I reckon no more than 2 years before they start to show signs they're breaking up.

Plus if you grow something temptingly rooty or bulby in them, I've found voles will chew through the sides to get at the crop. I just use them to store leafmould now.

[Dalrimple]

iv'e got a wall of them across my plot (7) ,i filled them with new manure in march 2016 ,i put 4 stakes at each corner and tide the loops over the tops with Tie Raps and the next bag tide to 3 and 4 post then 2 more posts and so on till youv'e got a wall ,I covered the manure and compost with black plastic and planted my courgettes through the plastic,this is the second year ive grown this way and once the plants got establised they didn't need watering as condensation was trapped under the plastic , i carn't see why it wouldn't work for other plants toms would be ok with about a foot from the top of the bag as this would give them a bit of shelter to start ,i will be emptying the bags this autumn and using the composted stuff on the plots ,the bags arn't showing any sign of brackdown yet but they where new when i filled them so it may be time to get rid ! atb Dal

[rary]

I tried the other year and it was a complete "fail" unfortunately, the soil kept drying out. Might have been better if i'd cut the bottom out. The size of the bags encourages you to fill with too much soil.

The reason I am thinking about using bags is to try and keep tree roots out of my soil so dont want to cut the bottom in any way, and using bags would solve the problem of what to do with the excess soil I would have if I just used pots, and as for drying out, that would be a unique experience, as there is hardly a week goes by without rain
Dal. did the way you held the bags in place stop them spreading out?
And thanks for the comments Folks