Raised beds

Kay_Peel

mutley74 wrote: »

I was just wondering how "easy" and how these things work. Can a simple wooden frame be placed on a grassed area? or does the grass need to be removed first?
Also do raised beds needs to be "connected" with the general soil? as i have read on some gardening pages people lining their beds with polythene sheets.

That's what I did, Mutley. I put a wooden frame directly onto a part of my lawn and laid a membrane of thick plastic sheeting in the bottom. I spiked the plastic sheeting with a garden fork for drainage. I'm really pleased that it took very little effort on my part - I'm not really into digging largish areas and just wanted to get planting. :beer:

mutley74

Kay_Peel wrote: »

That's what I did, Mutley. I put a wooden frame directly onto a part of my lawn and laid a membrane of thick plastic sheeting in the bottom. I spiked the plastic sheeting with a garden fork for drainage. I'm really pleased that it took very little effort on my part - I'm not really into digging largish areas and just wanted to get planting. :beer:

why use a membrane of plastic between the bed and existing eart? surely that will restrict drainage and movement of worms etc?

Kay_Peel

mutley74 wrote: »

why use a membrane of plastic between the bed and existing eart? surely that will restrict drainage and movement of worms etc?

Good question. I was following advice from an old boy in my local horticultural society. There were two reasons - to help retain moisture and to put a barrier between the dandelions in my turf and the new bed. I put loads of fork holes over it though - just as you say, to encourage some worm activity.

That's the thing about my raised beds - they tend to dry out, especially around the edges, near the planks of wood. You need loads of water-holding humus in the soil and if you haven't got much humus then 'needs must' with a bit of plastic sheet. And as for dandelions ...... well we all know that they are determined little beggars who will push their way through anything - but in six years they haven't appeared, but the worms are thriving.

Hope that helps! :beer:

mutley74

i got some offcut strips of 18mm untreated plywood - is this good enough to start a raised bed? or will it just come away when it starts getting wet and damp after a few months?

Lotus-eater

Personally I wouldn't put plastic at the bottom of a raised bed, for lots of reasons, but mostly because it is always there then, will eventually break up and be a pain,
I've used thick layers of cardboard in exactly the same way, it will eventually break down, adding some humus into the soil, will help with moisture retention while it is there and when it breaks down, you can dig deep and grow much better long root crops there.

It's only my personal way of looking at it though, so don't jump on me for not agreeing with you.

adouglasmhor

mutley74 wrote: »

i got some offcut strips of 18mm untreated plywood - is this good enough to start a raised bed? or will it just come away when it starts getting wet and damp after a few months?

I would say it woild not be much use, it will fall apart in weeks rather than months.

Lotus-eater

mutley74 wrote: »

i got some offcut strips of 18mm untreated plywood - is this good enough to start a raised bed? or will it just come away when it starts getting wet and damp after a few months?

There are different sorts of plywood, I don't really know enough about it to give you a definitive answer, but my instinct would be, yes, but it might leak something from the glue and it might not last very long.
I'm sure it would last the growing year, so if all you want is that to give it a go, I suppose you could do worse.

Lotus-eater

adouglasmhor wrote: »

I would say it woild not be much use, it will fall apart in weeks rather than months.

Lotus-eater wrote: »

I'm sure it would last the growing year,

:rotfl: There you go, two different views, come back and tell us what happened.

Orange_King

It would not be worth the effort imo - better go for something that will last much longer. I used fence boards, treated them with preservative and then covered the inner side with old compost bags to give a bit of protection from damp.

If you cut the plastic just right it will also help keep the soil inside the bed if the ground isn't level.

Lotus-eater

Orange_King wrote: »

and then covered the inner side with old compost bags to give a bit of protection from damp.

I could never see the logic in this.

Surely all you are doing is creating a huge area where the plastic will never let the wood dry out, the wood against the plastic will virtually stay permanently damp.
The thinner the wood, the more chance of it drying out, so your fence boards may be the best sort of thing to use plastic with.

But I still can't help but think this is maybe causing just as many problems as it solves.