[shokkyy]

I'm planning some raised beds to go inside my new polytunnel, and I'm trying to work out what soil depth I'd need in them. The tunnel sits on a lawn which I broke up, turned over and flattened. I want to be able to grow carrots and parsnips in there, in the hope they'll do better than my dismal failures outside. Will a depth of 1 foot in the raised beds be enough for that? If they're really determined they could stretch their roots down into the soil/old lawn beneath, but that will be very compacted. And I'm not sure whether I'll try to do any brassicas in there, but if I did would a 1 foot depth be enough for those too?

[sarajane]

Do you have any homemade compost.  We've a raised bed for our carrots and each year I put in loads of compost.  Its not too rich but breaks up the compaction in the soil and produces great carrots.  If you could dig some into the top 9 inches it will greatly improve your crops.

[cooperman]

a lot of coarse sand mixed in with compost makes a super medium for growing carrots in.
Plenty of FBB as well and a general feed of growmore helps.
I grow my carrots in 12" raised beds with no probs, I also use a lot of large containers as well, a bit like a la Bob Flowerdew really....

[shokkyy]

I do have lots of homemade compost, but this autumn I'm afraid it all has to go in my big veggie bed in the garden, which is sorely in need of nourishment. The new raised beds will have to be filled with imported topsoil. My local garden centre does have a good mix for veggie beds, which has a lot of sand in it.

Can anyone help with the soil depth for parsnips and brassicas? Will 12" be enough for them, given that beneath that there will be more soil albeit very compacted soil?

[mumofstig]

unless you are growing 'snips for show, you wouldn't need them longer than 12 inches, would you and that's plenty deep enough for brassicas  

[shokkyy]

unless you are growing 'snips for show, you wouldn't need them longer than 12 inches, would you and that's plenty deep enough for brassicas  

Oh great. Thanks for that. I just wasn't sure whether they'd turn into freakish misshapen blobs if they hit the hard bit with their end roots

[Yorkie]

Depends on the variety ...

[sunshineband]

Are you and DD competing now on the parsnip front? 

Wot a wopper 

and to get back on topic: Shokky, we grow decen enough parsnips at school in beds six inches deep , over pastureland that has had the turf turned over only.

Difficult to get the up sometimes as those tap roots delve themselves down deep, so I guess you'll have no trouble there 

[Yorkie]

I think he just edged that one - mine was longer, his was longer (or vice versa) and his was marginally heavier.

I couldn't remember the dimensions of mine so felt it easier to post the photo rather than search for my previous post!

[sunshineband]

I think he just edged that one - mine was longer, his was longer (or vice versa) and his was marginally heavier.

I couldn't remember the dimensions of mine so felt it easier to post the photo rather than search for my previous post!

Mr Sunny was well impressed anyway even without dimensions 

[shokkyy]

Not only is it huge but it's absolutely perfect too. But how the heck did you dig that up without breaking it???

[Yorkie]

Luck. And just the right soil conditions!