[withnail]

hi, im new to this site and gardening in general.

I have selected a site for our raised beds (crappy clay sub soil), however it is adjacent to quite a mature conifer hedge.

i realise this isnt ideal, but i dont have much alternative, apart from this hedge it is ideally placed. btw the hedge is north to the proposed plot

how best could i cope with the thirsty roots of the conifers ? could i line the raised beds with polythene and puncture just a few holes into it ?
or can i simply leave it be ?


thanks for your valued advice  

[WG.]

Water comes up the way as well as down so the polythene seems like a bad idea to me.  How far away is "adjacent" since many conifer roots tend to be fairly compact?

[withnail]

the beds will be tight to the hedge. along one side 1.4m  

the beds will only be approx 1.8m x 1.4m and i do know the roots extend beyond this.
i have cut off the roots in the topsoil where i have found them while digging it over.

i did think that polythene would probably present more problems of a different kind.

[WG.]

My suggestion would be to make the beds deeper so that they hold more moisture.  Incorporate as much organic matter into the clay soil as possible.  Gypsum and sand should also help to break up the clay.  Leave out the polythene.  Buy your carrots and parsnips from Tesco for at least another year until soil is improved (or trade for them with a neighbour).

Oh, and keep watching this thread while others weigh in with their advice.  

[Zak the Rabbit]

the potato patch ive just dug is within 2ft of a conifer hedge. The big problem you will have is removing the masses of fine roots from the conifers. Conifers tend to have 3 or 4 very thick main roots then loads of these fine roots.

As said before, dig a bit deeper. Ive double dug my bed

[muntjac]

as above ,and make a path edge along the conifers with a deep sharp edge  go down to 18 inches clearing what roots you can  and chop em off. rake the soil clear of the path trench running along it .so more surface roots dont grow back into the plot  

[withnail]

thanks for the input.

i am raising the beds 12" with concrete gravel boards, i have turned over the lawn and  topsoil and removed all roots that i have encountered so far.

i've just got to find about 2 tonnes of soil to fill them all up with
once finished  :shock:

[muntjac]

make that 1 tonne of manure and the rest soil and dont grow deep  roots on it this year  

[withnail]

i've just been reading a book i picked up from the library this evening, and i stumbled on a peice about this very same subject.
it suggested a "hip deep" trough lined with polythene, parallel to the hedge, cutting off all roots as found.

im not sure i fancy digging "hip deep" through solid clay, but i might go a bit deeper than i have already.



my sis-in-law has offered my some well rotted horse manure,  will tap her up about this at the weekend when i see her

thanks for the replies everyone

[WG.]

 trough lined with polythene

Just for the record withnail, does "lined" mean sides and base, or just sides?

[withnail]

mmm not sure, will have to look more closely at the exact wording in the book.

:bah: trying to paraphrase, and someone picks the bones out of it  :roll:  

will get back to you on that one  

[WG.]

[withnail]

ok m8....

and i quote

the plot should be kept well away from big hedges - especially leyland cypress and privet which will steal any goodness and moisture from the soil. Competition from any nearby trees and hedges can be reduced by digging a hip-deep slit trench parallel to them, cutting out and removing their roots and preventing them from returning by setting in a continuous plastic sheet before refilling the trench.

from bob flowerdew's organic bible page 140  


not sure if it answers your question even now, probably it doesnt matter if the bottom is lined or not, if your going to the trouble of this, then a 200mm extra wide peice of plastic (or polythene ?) wouldnt break the bank

i know couch grass roots can pierce polythene but can other roots ?

[WG.]

I don't think he is talking about a raised bed at all - only a lined trench to keep the roots from wandering.

[withnail]

probably true, but if the slit trench should be dug to a hip depth, surely it matters very little whether the bed is raised or not ?