[Sparkyrog]

I am considering constructing 2 bed's out of railway sleepers for my parsnips and carrots "maincrop" These would be roughly 1200cm x 5000cm any thoughts ?

[Sparkyrog]

oops it should of read mm

[mumofstig]

what's that in feet and inches? 

[Kate and her Ducks]

Was thinking, Wow! 50 meters!

[sunshineband]

    That would be one he$$ of  abed, Sparkyrog 

But converting to mm: bear in mind that you ideally need to be able to access the whole bed without treading on the soil, so 1m 20cm across would be fine.

You would also need to walk around to work from both sides, so I wonder if 5m is a bit long?

The width would easily lend itself to building an enviromesh cover too, to protect against carrot fly 

[Sparkyrog]

  That would be one he$$ of  abed, Sparkyrog 

But converting to mm: bear in mind that you ideally need to be able to access the whole bed without treading on the soil, so 1m 20cm across would be fine.

You would also need to walk around to work from both sides, so I wonder if 5m is a bit long?

The width would easily lend itself to building an enviromesh cover too, to protect against carrot fly 

We are in a garden here not on an allotment and I have two beds more or less the same on either side of a central path ! A couple of years ago I decided to make things easier for when I get older ,so  around the inside of the hedges I sank 25mm netting to keep the ******** Rabbits out inside this I put down slabs with membrane and gravel taking up the slack these beds would be the width of one bed ! I could put in several but dont think it would be cost effective ! Two would allow me to alternate ,I dont think 3 is justified on the cost 

[Kate and her Ducks]

My beds are with 5 or 10m by 1m and they work pretty well. Admittedly I sometimes take a shortcut across a bed providing whats growing is small enough to leap over.

[Kristen]

I am considering constructing 2 bed's out of railway sleepers for my parsnips and carrots "maincrop" These would be roughly 1200cm x 5000cm any thoughts ?

I considered sleepers to "frame" mine, but with beds 4' wide (max to be able to reach from either side) and 18" between them for paths, the width of the sleepers becomes significant and after 4 beds the sleeper surrounds would have used up the width of another bed!! so I opted for "planks" instead.

If you just have two raised beds what about crop rotation?

Dunno what sort of sleepers you are considering, but the old ones ooze tar and creosote and I wouldn't want that near my food crops; no fun to sit on or touch on a hot summers day when the tar is runny either

New ones are treated with something that should be fine for crops, but I've never seen any evidence that "buried"  the chemicals are safe for food crops, all safety information seems to be be when the wood is in a dry, above ground, environment.  I've shielded mine from the soil using damp proof membrane - although who knows whether the plasticisers will leach from that into my food crops.  Clearly it is possible to over-think the risks!!!

[Sparkyrog]

I am considering constructing 2 bed's out of railway sleepers for my parsnips and carrots "maincrop" These would be roughly 1200cm x 5000cm any thoughts ?

I considered sleepers to "frame" mine, but with beds 4' wide (max to be able to reach from either side) and 18" between them for paths, the width of the sleepers becomes significant and after 4 beds the sleeper surrounds would have used up the width of another bed!! so I opted for "planks" instead.

If you just have two raised beds what about crop rotation?

Dunno what sort of sleepers you are considering, but the old ones ooze tar and creosote and I wouldn't want that near my food crops; no fun to sit on or touch on a hot summers day when the tar is runny either

New ones are treated with something that should be fine for crops, but I've never seen any evidence that "buried"  the chemicals are safe for food crops, all safety information seems to be be when the wood is in a dry, above ground, environment.  I've shielded mine from the soil using damp proof membrane - although who knows whether the plasticisers will leach from that into my food crops.  Clearly it is possible to over-think the risks!!!

I was thinking alternating would be sufficient  I would have room for two rows of each in a bed !

[Kristen]

3 or preferably 4 year rotation normally recommended.  Two main reasons, firstly that it gives time for any bugs / diseases specific to the crop to die out between crops of like type being planted in the same place again, and secondly to allow the nutrients to recover - different types of plants placing different demands (and in some case replenishing them).

For example, root crops like Carrots and Parsnips fork if the ground is freshly manured, so manuring is done for one/several of the other years in the rotation, so that there is no need to manure prior to the year when roots are sown in that zone.  Similarly with Liming to adjust the pH.  It would be more difficult to manure the ground if it was mono-cropped with Root crops.

[Sparkyrog]

You misunderstood me Kristen . I intend all 4 rows to go in one bed per season, and I have never had a problem with roots in ground manured the previous season . I have not had to lime here in 30 years 

[Kristen]

You misunderstood me Kristen . I intend all 4 rows to go in one bed per season

Still not understood then, sorry.  Are you intending to move the raised beds to get crop rotation?

[Sparkyrog]

if in one bed one year then the other the next year when they go back in the first bed carrots will go where the parsnips were and vice versa that way to my mind they will only be in the same spot once every three years .

[Kristen]

Ah, I see.

Carrots and Parsnips both effected by Carrot Fly.  Obviously parsnips not to the same extent, but there is some evidence that Canker is exacerbated on Parsnips by Carrot fly.  Whether having Carrots or Parsnips every second year will impact on nutrient recovery I don't know.  Depends how much compost / manure you add and what other crop you grow in the intervening year I guess, but I suspect that part will be fine.  Don't know if there are other bugs / diseases that will linger - its not like roots catch anything persistent, that I know of?!!, like Brassica Club Root or Onion White Rot.

[J_B]

i have just sued normal timber rather than railway sleepers its much cheaper ...definitely work it for wht u are planning