Kitchen Garden Forum

I understand Comfrey is a good source of nutrients, especially P & K. I assume the plant finds & extacts these in the soil as its roots extend out.

However I'm puzzled in how the plant can continue to find these nutrient year after year in the same patch. You'd think it would start to deplete them after a while, then start becoming less useful.

Do any of you know the secret? Is it advisable to start a new comfrey patch after a few years in a different place?

Hi Colin,
It's not a secret really. The nutrients are measured in Parts Per Million and also you only take part of the crop and as the remaining vegetation dies down it releases some back into the soil to eventually to be picked up by the plant again. I have never found it necessary to move my Comfrey and it has been on the go for more than thirty years in the same place.
Every Autumn it gets a very good dose of Pigs Slurry which it seems to thrive on. Of course Pigs Slurry is not available to everybody but a good feed of any slurry will do. Pig Slurry used not to be used but since the end of Swill Feeding it's as good as any other manure if composted with a goodly amount of straw.
Does this answer your question? If not I'll have another go at explaining what I mean.

Another reason for not moving Comfrey is that if, like me, you don't get it all out in one go it grows back time and time again.

Hi weed,
Sod's Law decrees that it only regrows when you don't want it to!!

I get several harvests of comfrey each year, and every time I cut I put something around the plants - spent hops, horse manure or compost - it only seems fair!

Hi Sprout,
I too get several cuts from my Comfrey, three to be more precise. I feel that because Comfrey is a deep feeder my Autumn manuring has leeched into the soil and when the Spring growth begins that manure has reached exactly where it is needed. I appreciate that there are several views on leeching by I hold steadfast in the view that it is the right way to go.
Your mulching, when you look at it closely, is really a form of leeching. By laying the nutrients in a blanket cover on the surface, and for them to be of any use nutritionally speaking, you rely on leeching to take the nutrients to the target.
I feel that to feed your Comfrey as you pick it could well be a waste of useful nutrients and may well be better employed elsewhere around the plot.
Sprout, please do not think I an picking holes with your methodology I am merely trying to put another point of view.

I'll take a leaf out of your book johnboy - I mulch partly to make sure no weeds sprout between the comfrey plants when they are re-sprouting (straw and spent hops), but will save the most nutritionally 'heavy' (pony poo) for after the last autumn cut this year I really appreciate your advice, can take all you can offer!

I park my wheelbarrows in the comfrey bed when I am mowing and filling them for moving to the compost so it gets a light mulch every couple of weeks from spillage. It is also over the soak away of my septic tank so I guess that helps it thrive from year to year and give me 4 or 5 cuts per year to mix into the compost.

Hi Sprout and Geoff,
The reason why I only take 3 cuts is because of the size of the bed. There are 625 main plants of Bocking 14 and probably hundreds of offshoots. I used
to take 4/5 cuts but my needs are not that great now since the Nursery has been closed.
I mix Comfrey with chopped straw (Barley) and last week before the rains went over the stubble in the field next to me with my sit-on mower and that does the chopping for me as I go. I avoid patches that have any weeds.( which are very few.) I now have masses in the barn and certainly enough for the year.
I used to make potting up mixture for the Shrubs and other plants I used to produce.

Johnboy wrote:I only take 3 cuts

Hi Johnboy,
Could you elaborate a little on when and how - are the three cuts based on time of the year or the state of the comfrey plants, and how severe is a cut?

I have a very modest 5 plants (625 must look amazing!) so am thinking more along the lines of pruning leaves as it were, but do you just chop the whole plant down? how much is left?

Hi Belinda, I get four or five from my ten plants - starting as soon as the plants are away and flourishing, with the last cut in early September so as to give them a good uninterrupted leaf-ing before they die down.

A sickle does the job nicely - swish, just above ground level, and they're harvested. Only stumps left, and the first time I thought oh no, that's done it. About four days later the new leaves start to come up, and after two weeks you wouldn't know they'd been cut!

Thanks for the info Sarah,

I'll sharpen the sickle next spring and try not to worry that I've chopped them too low.

Every Autumn it gets a very good dose of Pigs Slurry which it seems to thrive on.

Thanks Johnboy - that's what I was really after. I don't particularly want to move the plants. However I was puzzled about how they didn't deplete the nutrients after a while. It seems the answer is to keep the soil they're in "topped up".
I assume that we actually have a choice of:
- Adding things like your slurry to the comfrey, which in turn produces another version of fertilizer, or
- Cut out the middleman and apply the slurry direct to our garden.

Since so many people use Comfrey, I guess it is just a much better means of finding and assembling a balanced range of the important nutrients than trying to do the same yourself?

It's worth pointing out that if you don't want it to spread all over the place use Bocking 14. I got some other varieties that I bought direct from Bocking loose in my garden and a neighbour's garden that I used for a time, it took many years of vigilance to get rid of it.
I have had Bocking 14 in a patch for 12 years now, just when it could be cut it goes down with mildew so it can't be everybody's 'cup of tea' as the saying goes, you have to have what makes it grow in your ground in the first place.
If it's not a major source of NPK but only micronutrients then surely seaweed extract would be easier to get and use if you haven't got acres of land.
Allan

does anyone advocate laying comfrey leaves on the soil surface around tomato plants rather than making a liquid feed out of them?