Before the plant grows so large it gains sentience and tries to strangle me.
This is year three or four of having just gobs and gobs of Comfrey grow from the maybe 2 plants I planted as a green mulch for the marionberries. That itself was a mistake as no blackberry in the history of blackberries has ever needed help growing very very big.
That said I’m less worried about the marionberries this year then I am about the rapid growth of the comfrey. Why? Because when I paved the space for the greenhouse I purposefully pulled all the comfrey remaining and hilled up some very marginal dirt, thinking that it would be the end of the plant.
I was incredibly wrong.
I am, as you can see, a fool.
Being wedged in-between a fence and a greenhouse has been no impediment for this plant, and this isn’t even the half of how large it was. This was what the plant(s) looked like after I had already harvested some for the tea bucket.
I planted the comfrey initially to make comfrey tea with it- a positively awful smelling brew made by putting comfrey leaves in a bucket with water and waiting until the whole mess smells like a combination of elephant dung and rotting flesh. You can then dilute the resulting foul smelling distillate with water for a natural fertilizer. I finally used up the bucket I’d put last years growth into- and it was time to make more.
The plant while not steeped in water smells just fine- so the making of the fertilizer isn’t an unpleasant chore.
Well it’s a chore with the hazard of having to reach in between a blackberry thicket and a greenhouse in order to cut it, but that’s why gardening gloves were invented.
All and all it was a success and now a new bucket of ass smelling fertilizer is fermenting under the apple tree as I type. Pro-tip! If you watch a British gardener talk about how you can just harvest comfrey for free and make a fertilizer from him, you should probably note in your head that said plant grows like the literal weed that it is, and not plant it in a marginal space expecting it to remain tidy and contained. I’m very lucky that I planted the sterile cultivated variety that only spreads via the roots and not by the seeds.
So I only have a King Kong sized problem rather than a Godzilla sized one.
At least the bees are happy with the comfrey flowers.
This delightful fellow fell so sound asleep in this flower that I could move the whole top stalk, sleeping bee included, over to the work table so my stripping the plant for leaves wouldn’t hurt her. This bee has been hard at work, you can tell by her delightful little pollen pants on her back legs. She must have spent the whole day buzzing around gathering pollen, until her energy ran out while wedged in a comfrey flower. Looks comfy!
By the next morning she’d flown away, hopefully well rested and ready to return her pollen to the hive.
And for the sake of her nose hopefully her hive is as far away as possible from the cursed bucket under the apple tree.
The Neanderthal Gardens 
That is too much work for fertilizer. I suppose I would do it though if I had the time and energy for it. I sort of did it with the foliage of cannas, not intentionally, but because I wanted to grow the canna rhizomes, and a lot of foliage comes with that. It works like a cover crop, but is not as ‘nutritious’ as fertilizer teas. Nor does it get tilled in where it grows. I cut the tops off and lay them over soil somewhere else.
Eh it’s not too much work- 5 minutes of stripping the leaves from stems, shoving it in a bucket- covering it with water and then waiting a few weeks. Just turns into a smelly time bomb in the corner of your garden.
I would not want to deal with the overgrowth though. Even with the cannas, they are too much like weeds until I cut them. I will grow less of them in the future. Have you heard of using cattails for fertilizer? I thought that was what my great grandfather used, but can find no information about it.
Interesting! I’d have to look it up
I don’t know if you can. I find nothing about it.