Powdered Comfrey

A few years ago I had a friend in horticulture school. The class was growing the same plants in the same soil, in the same greenhouse. The only difference was each student was able to choose their fertilizer.
At the time I was drying comfrey in the back of my SUV. A simple setup of half inch wire mesh fixed atop a concrete mixing pan. It’s didn’t take long in the summer for it to turn to powder so I offered him some.
The other students weren’t quite as inventive and used all sorts of synthetic fertilizers. Half of his plants got a fishy smelling emulsion while the others received one quarter cup of comfrey per gallon.
Out of all the plants grown the fish emulsion worked best. The surprise came from the comfrey plants as they matched the synthetic fertilizers in growth and color.
That old SUV is long gone so now this is my setup. In one week I can crush the dried leaves but they’re not powder yet. I’m also experimenting with lambs quarters and mimosa leaves. Everything I dry now will be used in next year’s homemade potting mix. I’m probably going to make a homemade dehydrator this winter for such uses next summer.
Unfortunately I have no data or measurements to prove this works but will continue to use it.
I hope some of you will too. I’d love some future feedback.

I think I am going to follow your lead on this. I actually had a bear pop the top off a bucket of comfrey tea last week and dump it all.  (I like to picture him swilling it all but that seems unlikely.) Drying it seems like a way to avoid this...

I have seen various N-P-K numbers for dried comfrey on the net. Up to 3.5-1.2-8.4 but that seems pretty generous...

I wonder if using a heavy needle and very light string would allow me to hang some of my comfrey like an impromptu clothes-line? I don't know if I'll get that far today, but I'll add it to my enormous list!

You may be able to smell that bear quite a ways off! That is a pretty generous NPK, I wouldn’t have expected as much.

That does work well Jay. Those thick stalks are great for hang drying. It didn’t end well for me since I was working twelve hour shifts at the time. I arrived home to find it had all broken up and blew away.

Scott, I love the idea of powdered comfrey!  I always grow some comfrey for chop&drop right next to my garden beds.  Unfortunately I really need the comfrey right at the very beginning of the season when the comfrey is at its least growth.  By the time I get a decent crop of comfrey I no longer need the comfrey.

I would love to harvest my comfrey and store over winter so I could use during spring.  Do you think it would last this long?  Could you give just a few more details on how to dry and store over winter?

Eric

I wonder how different the nutrient release rates are for different dried dynamic accumulators.  Comfrey seems to break down very quickly.  A study to test the nutrient release profiles vs. the species used would be super interesting.

Eric Hanson wrote:I would love to harvest my comfrey and store over winter so I could use during spring.  Do you think it would last this long?  Could you give just a few more details on how to dry and store over winter?

I store other herbs over the winter, so my general suggestions are:
1. leave the pieces fairly large and powder it just before use.
2. store in large glass jars (like the industrial pickle ones) with a solid lid as plastic lets moisture in.
3. make sure it's good and dry - in my humid area, that means putting it in the oven on dehydrate for the last bit of drying, and then putting it straight in the fridge to cool in a low humidity environment, and *then* putting it in the jar. That's a bit of a nuisance, but it makes a huge difference in stuff I thought was "dry enough" not going moldy on me!

Scott Stiller wrote:

I arrived home to find it had all broken up and blew away.

Thanks for the warning. With our humidity, and the spot I was thinking I'd hang it, I'd probably be safe, but it would be annoying to do that much work to then lose it all!

Thanks to everyone for the compliments! I figured I may only get some eye rolls! 😂
By far the most efficient way I’ve ever done this is in the back of an SUV. Whole leaves are powder in ten days here in NC. I’m fairly pleased with the soda carrier setup. Crushable in one week was more than I expected.
You can start out with a lot but only get a small amount of powdered for storage. I’ve tried it in mesh seed bags which wasn’t great. If you drop the bag lots of powder gets left on the floor. I now store mine in quart jars through the winter. I can do this for months but only end up with two quarts for next spring.

I was going to try grabbing a big arm load and tying it together by the stems near the bottom, hanging it upside down in my shop to try to dry it.  My thought was using it to help supplement my chicken food through our long winters.  Anyone have any idea if this would work or if bundling it would make it take so long to dry that it may mold?  There are probably too many variables for a good answer, temp, humidity, and the like.  I may just have to try it.  Worst case, it ends up in the compost bin.  I have so much of it, that isn't an issue if it works out that way.  

Good thoughts Scott.

edit: spelling

I just built another big flower bed…over established grass.  I put down thick cardboard and all the comfrey cut from about 30 huge plants for mulch.  Then dirt.  I’ve done this many times.  The big old stocks and leaves will be lovely black stuff by spring no matter how bad the soil is on top.  

I used it to top dress my garlic beds last year.  I just pile it on after planting and throw sawdust on top.  No weeds.

If I was going to dry it I would hang stalks and all.  

It’s just more expeditious to pile it on green.

I like it. so the object is to get a nutrient dense supplement for seed starting that will release as the seed roots get to the point of needing it.  I have seen such good results from using biochar as a seed starting medium so supplemented with the comfrey concentrate should support the biome development.  Will hang some scraggily comfrey  in the green hose while it is still overheating and see what I can get.

That is an excellent idea if you want to dry things fast. I remember my sister drying chanterelle mushrooms that way. Putting them on a string works really slick and they get air from all around. You would not want to put it in a breeze though as the wind might tear the leaf away from the string. I've kept garlic and onions on a string to cure them while I was busy with the dehydrator on a different project.
As fertilizer, I feel that comfrey cannot be beat. I have quite a few young plants of comfrey. I plan to put one or two next to every fruit tree. In the Fall, as they dry and the leaves rot away, they will produce fertilizer for them and prevent other weeds from getting close to the tree. IMHO, comfrey should be part of every fruit tree guild. I still have some comfrey in barrels of water to distribute to asparagus this Fall.

Has anybody tried freeze drying comfrey? I saw a guy on youtube who put kale and a little water in the blender to make a thick paste, then he ran it through the freeze dryer. The result looked kinda like deep green styrofoam that crumbled easily into a fine powder. If put in an air tight container it will last essentially forever!

I'm saving up for a freeze dryer now so if nobody else tries it first I'll let y'all know how it went.

N Stephanson wrote:Has anybody tried freeze drying comfrey? I saw a guy on youtube who put kale and a little water in the blender to make a thick paste, then he ran it through the freeze dryer. The result looked kinda like deep green styrofoam that crumbled easily into a fine powder. If put in an air tight container it will last essentially forever!
I'm saving up for a freeze dryer now so if nobody else tries it first I'll let y'all know how it went.

I was wondering, is there an advantage in freeze drying comfrey? [better color, more potency perhaps?] I was thinking about it, but then I figured I can dry my comfrey [in the dehydrator] just as easily and for a lot less money.
You are so correct about an *airtight* container, that's for sure! My tin cans just won't do! I use it as tea, once in a while.
Once dry, comfrey crumbles very easily between my fingers too.
I suppose if you want to make a big production, and sell the comfrey, going through the expense of freeze drying it might be  worth it. How do you use your powdered comfrey? Do you sell it?

I haven't actually made any yet as I'm still saving up for the freeze dryer, but the 2 big draws for me how are long it will keep and the fact that they claim that freeze dried foods keep well over 90% of their nutritional content compared to regular drying's 60-70%.

Edit: yes, the idea is to sell it eventually.

N Stephanson wrote:I haven't actually made any yet as I'm still saving up for the freeze dryer, but the 2 big draws for me how are long it will keep and the fact that they claim that freeze dried foods keep well over 90% of their nutritional content compared to regular drying's 60-70%.
Edit: yes, the idea is to sell it eventually.

Yes, I can see that as a big draw too. I'm not looking to sell, though, so I can regulate how quickly it gets used. It does drive decisions. As far as keeping it nutritious, airtight glass jars [with the white plastic lids] are my go to.
Any dried food will deteriorate if the wrapping is not airtight, so I suppose you have a way to keep it airtight for a long time if you aim to sell it, but yes, your process will be superior.

This thread is interesting to see! I've been dehydrating and powdering just about every piece of compostable waste that I can get my hands on in preparation for moving in the future.
Eggs, bread, slimy lettuce, potato peels, old tomatoes, citrus rinds, onions and banana peels - everything gets dehydrated, powdered, and stored for later.

My hope is to have at least 10 pounds of powdered goods for soil improvement wherever I go. I'm going to try taking small amounts out and mixing them into the soil of indoor plants as well.
Here's a photo of my initial container. I've switched to a bigger container now, but I like this photo because it shows the different layers.

I love the freeze drying idea! I have a friend that buys alfalfa cubes to boost the heat in her compost. I never told her how insane I think it is. Twenty bucks for a few small grass cubes; no thanks. I can’t wait to see your results!

I am glad I found this thread. I was considering how I can create my own fertilizers, especially for indoor plants, and the idea of drying comfrey came to mind after completing it for a BB. I am going to roll around how to trial the effectiveness of this, some kind of trial grow to see if noticeable growth changes can be observed.

I found a needle and strong thread was more than enough to hold up comfrey to dry. Straight through the center of the stalk does it.

Timothy Norton wrote:I am glad I found this thread. I was considering how I can create my own fertilizers, especially for indoor plants, and the idea of drying comfrey came to mind after completing it for a BB. I am going to roll around how to trial the effectiveness of this, some kind of trial grow to see if noticeable growth changes can be observed.
I found a needle and strong thread was more than enough to hold up comfrey to dry. Straight through the center of the stalk does it.

Comfrey is a fantastic fertilizer, and it can be cut again and again, even here in zone 4b Wisconsin. like 3-5 times in one season. If you have many comfrey plants, you never run short!
I am too lazy to dry it, besides, sometimes, I give it directly to my chickens. [They love it!]
I have, dispersed in the garden some 55 gallons barrels to which I added a spout towards the bottom so I can attach a garden hose.
I do a cutting and stuff the material in one of those paint filters mesh. They are pretty cheap and come usually in 5 gallon size, so you can place them over a homer pail and stuff the bag. Then, just use a string or an elastic to close the bag. Plop it in the barrel and fill with water. Let it "work" for 2 weeks. Then you can pour it on your crops It smells really powerful after 2 weeks! Some folks dilute it. I use it 50/50 with more water. If it is very smelly, pour it on the ground, at the foot of plants. If light, you can use it as a foliar spray. [just with a watering can because a sprayer might get clogged]
Here is another how to:
https://gardenerspath.com/how-to/organic/comfrey-tea-fertilizer/#How-to-Make-Comfrey-Tea-Fertilizer
The reason I use a filter bag is that I attach the hose to the barrel and in this manner, I filter the goo. It doesn't clog my bag, and I never have to touch it. [When I'm done with the  bag, I lift it, tear it open and empty the bag by a tree for compost/mulch/ fertilizer, then repeat...]

I’m glad you found this helpful. Even with a lot of comfrey leaves you’ll only be left with a small powdered amount. It really seemed to help though.
Over the past two years I’ve had I lot of aloe plants. After doing some research I decided to try blended aloe leaves with water as an indoor plant booster. It has worked amazingly well! Plants that are really suffering bounce back to life with a day or two.
I have used a little aloe and a lot; both seem to work well!

The flower stalks and leaf stem contain allantoin gel which is released when crushed.  So it may be a source of instant fertilizer in contrast to the dry powder which would have to be biologically broken down to be available.  Another interesting comparison to try.