Gardening question

Posted by: Officer DBL on 07 April 2009

I have just built a raised bed of recycled railway sleepers (and have crushed a finger tip into the bargain) and I now need to fill it with soil.

I have spoken to a local recycling company and they will supply me with a bulk load of recycled compost. Can I use this compost on its own or do I need to include proper topsoil in the mix?

KR

Brad
Posted on: 07 April 2009 by Fisbey
I wouldn't personally use just compost - dependant on the compost itself it may not drain very well. Maybe add some topsoil and/or grit to help drainage.
Posted on: 07 April 2009 by JWM
Sorry about finger - goes with the turf I'm afraid!

I agree with Fisbey, mixing with topsoil (perhaps 50/50) is a good idea. Compost on its own could in fact be over-rich. If your topsoil is a bit heavy, some grit will help the structure. Mix well before putting in (you're going to be fit!).

If the raised beds have been built over a grassed area, there is no need to dig out the grass because it will be killed off by the exclusion of light by the depth of the soil and will itself add nourishment.

HOWEVER (grassed or not) do at least roughly dig over to loosen the exiting surface, to stop the possibility of an inpenetrable pan developing.

Have fun. I've just slipped a disc which is a bit problematic for my own gardening...!

James
Posted on: 07 April 2009 by Bob McC
I did exactly this a while ago and advice was compost would be too rich on its own. Mixed it 50/50 with top soil. Now got my broad beans in looking good!
Posted on: 07 April 2009 by count.d
I agree with you both, but I don't like using grit as I find it makes the mix too heavy.
Posted on: 07 April 2009 by tonym
A slight note of caution - recycled railway sleepers are deeply impregnated with a tarry wood preservative which gradually leaches out into the surrounding soil and onto their outside surface. Whilst it won't poison all the soil in the raised bed, it will nevertheless contaminate the bit closest to the wood, so don't plant too close. And don't sit on them!

Coincidentally I've just built a raised bed for growing vegetables and decided to use peat-based (bagged) compost, the logic being that my soil is stuffed full of weed seeds & it would be rather nice not to spend hours pulling the blessed things up.

The only problem is that there appears to be a hole in the universe in the centre of my raised bed which has eaten innumerable bags of compost. My veg. is going to be tasty but very, very expensive... Frown
Posted on: 07 April 2009 by Officer DBL
Thank you for the replies. I will order some topsoil at the same time as the recycled compost to make up a 50/50 mix.

Tony, I will be careful with the sleepers. The bed will be ornamental, but I will take your advice on not planting too close.

James, I hope your back gets better soon. At least I can still get on with stuff in the garden, but I am having to adopt a different approach to the keyboard as I can't use my ring finger on the letters W, S and X (trained as a typist years ago you see Roll Eyes).

KR

Brad
Posted on: 07 April 2009 by deadlifter
the best thing to do before you put any soil/compost in is to line the raised bed inside with terram or any other product that act`s as a membrane that allows liquid to travel through it one way and therefore not allowing weeds and such like to come through into the mixture you fill the bed with, thus making weeding very simple and pain free
Winker Big Grin
Posted on: 07 April 2009 by BigH47
quote:
Originally posted by deadlifter:
the best thing to do before you put any soil/compost in is to line the raised bed inside with terram or any other product that act`s as a membrane that allows liquid to travel through it one way and therefore not allowing weeds and such like to come through into the mixture you fill the bed with, thus making weeding very simple and pain free.


Assuming you can stop dandelion seeds floating in.

If they could cross rice/potatoes/maize with a dandelion they could solve world hunger, the bloody things grow anywhere and in about 2 minutes flat.
Posted on: 07 April 2009 by deadlifter
quote:
Originally posted by BigH47:
quote:
Originally posted by deadlifter:
the best thing to do before you put any soil/compost in is to line the raised bed inside with terram or any other product that act`s as a membrane that allows liquid to travel through it one way and therefore not allowing weeds and such like to come through into the mixture you fill the bed with, thus making weeding very simple and pain free.


Assuming you can stop dandelion seeds floating in.

If they could cross rice/potatoes/maize with a dandelion they could solve world hunger, the bloody things grow anywhere and in about 2 minutes flat.


granted, but any weeds will only be surface and not deep in the mix therefor making regular maintainance easier Winker
Posted on: 09 April 2009 by Wolf2
Yes the tar is nasty and poisonous, as are the green treated lumber so no veggies should ever be planted. Rough up the original soil to allow water percolation and put in your top soil/compost. As I understand it creating abrupt changes in soil horizons creates problems with root/water penetration.

But top dressing planting beds with compost on a regular schedule is the best way to keep beds weed free, or easy to pull, and absorbs moisture reducing needed watering and fertilizers. This also enhances the worms numbers in beds which actually do a lot of work for you in tough soils mixing it with their digestion.

One friend had a hedge of Eugenia and he kept throwing grass cutting and hedge trimmings underneath. As storm water drained into that area eventually the soil was so loose and dark the neighbors property didn't get inundated. When he dug every shovelful had worms.
Posted on: 09 April 2009 by Absolute
If planting young plants, a bit of fish blood&bone mix a good idea, gives them an extra bit of nutrients to get started. Just sprinkle a bit in when you are planting up, it doesn't need to mixed through out the bed.
Posted on: 09 April 2009 by deadlifter
quote:
Originally posted by Wolf2:
Yes the tar is nasty and poisonous, as are the green treated lumber so no veggies should ever be planted. Rough up the original soil to allow water percolation and put in your top soil/compost. As I understand it creating abrupt changes in soil horizons creates problems with root/water penetration.

But top dressing planting beds with compost on a regular schedule is the best way to keep beds weed free, or easy to pull, and absorbs moisture reducing needed watering and fertilizers. This also enhances the worms numbers in beds which actually do a lot of work for you in tough soils mixing it with their digestion.

One friend had a hedge of Eugenia and he kept throwing grass cutting and hedge trimmings underneath. As storm water drained into that area eventually the soil was so loose and dark the neighbors property didn't get inundated. When he dug every shovelful had worms.



Originally posted by deadlifter:
the best thing to do before you put any soil/compost in is to line the raised bed inside with terram or any other product that act`s as a membrane that allows liquid to travel through it one way and therefore not allowing weeds and such like to come through into the mixture you fill the bed with, thus making weeding very simple and pain free.
AND VEGGIES CAN BE PLANTED AND GROWN Roll Eyes
Posted on: 09 April 2009 by Wolf2
I like fish and bone and blood meal but often marauding animals and frisky dogs LOVE to dig that up to find something. I had clients that hated the smell but it's gone in a day or 2.