[ConfusedGardener]

I've got some Bocking #14 which was started off in pots, but I've not got around to digging a bed for. We have quite a lot of big stones and rocks in the ground here, so I'm wondering if I need to dig deep so that the roots can reach down to get the nutrients.

I did search for advice, but all I could find was a page suggesting that Bocking #14 strain “is shallow rooted and subject to drought”, which is not what I was expecting!

The page is here: http://www.coescomfrey.com/grow.html

[cadalot]

I bought 10 root cuttings off ebay and grew in pots then planted on the allotment, they grow like mad and I have cut all of the plants back down to the ground at least once this first year and some of them twice. New growth appears in days after you cut them so if they are not really producing until 3 years old as that article suggest I will not be short of comfrey for feed and manure.

I now have a comfrey pipe set up and production of comfrey tea is much better and less smelly that the other methods I tried, see my diary for details. 

[surbie100]

You shouldn't need to do anything fancy for them, they are as tough as old boots. Just pick your site carefully because they are difficult to get rid of, like horseradish.

I moved my plants this year, couldn't get all the root out because they go DEEP really quickly, and now I have 3 plants grinning & waving at me from inside the new strawberry bed. When I get those out, I imagine I will get another 3 or 4 popping up again in the same space from bits of the same root. 

On the plus side, I've what looks like an eternal supply of new comfrey plants!

[ConfusedGardener]

So 2-3 feet should do? Even though there might be quite a bit of firmly packed stones and rubble below?

As well as chunks of slate up to 1' or 2' in length (usually a bit less wide) there are also bricks and general builder's rubble. I'm finding that I need a pic-axe to effectively break through the rocky subsoil when digging my other beds. It is basically "virgin ground" that has not been dug in decades here, and certainly not for the purpose of growing plants.

[surbie100]

I've got claggy clay-based topsoil to about a spit's depth, then a hard pan of either orange or blue clay. The comfrey has happily found a way through, it's determined stuff and roots are tiny threads to begin with.

[mumofstig]

I'd just dig a hole big enough for the pot contents and plant them.

Here the roots broke through a plastic pot, and grew down through soil that needs a pick axe!
I certainly wouldn't try to dig deeper, as they will do the work themselves.

[gypsy]

I left mine on top of the soil for a week as someone gave it to me and then I was out of sorts for a while and could not plant it. It planted itself. That was a few yrs ago, now I have a whole bed of comfrey plants all self propagated.

[ConfusedGardener]

Thanks for the replies and advice. It'll be nice not to have to put some serious work into a bed for a change!