the value of alder (Alnus glutinosa)

Curious to know whether anyone followed through on tapping red alder for sap, and how that went?

We have lots of red alder at our new place and according to one of my herb books the sap is rich in vitamins and is consumed as a tonic. So I am starting to think seriously about tapping.

Have been considering transplanting some red alders as nurse trees in our chestnut polycultures but the conditions seem awfully dry in summer for alder up on the hill where the chestnuts will be going. So I started thinking another option to make use of the nitrogen fixing ability of the big alders growing like crazy in their preferred habitat on our lower wetter ground is to rake leaves in the fall and use them to line the swales we will be building this winter. And I want to share a link to a paper I found that is relevant to that idea.

https://helda.helsinki.fi/bitstream/handle/10138/18754/67-1959_Mikola.pdf?sequence=1

It's an experiment from the 1950s showing far more growth in pine seedlings mulched with alder than several other species' leaves. Table 3 shows a major difference. Pretty cool eh?

By the way, I never did get any responses to my inquiry as to whether anyone had been tapping alder sap? Any results to report?

Andrea Locke wrote:Curious to know whether anyone followed through on tapping red alder for sap, and how that went?

We have lots of red alder at our new place and according to one of my herb books the sap is rich in vitamins and is consumed as a tonic. So I am starting to think seriously about tapping.

I'm not sure about alder, but birches (which are relatives) have between 0.5%-2% sugars in their sap, while maples run 1-5%, and sugar maples in optimal conditions can possibly even hit 6%. My silver maples here calculate out to about 3-3.5% sugar content, but they are in good soil, planted in a single row along a field edge, so they get full sunlight.

With respect to syrup production, the amount of syrup yielded by a given amount of sap will be less. It will taste different, but I've heard it's good. It's not something I've ever tried myself.

Howdy folks.

It's been noted in the thread here that Alder is suitable for the cultivation of a number of species of culinary mushroom (you can put Hericium species on that list also) -- but I thought I would add that Alder chips are considered the substrate par excellence for the outdoor cultivation of several wood-loving species of the genus Psilocybe. Including Psilocybe cyanescens, Psilocybe azurescens, and a few others.

... in case that's of interest to anyone here, for medicinal purposes against anxiety and depression (for which there is a growing body of efficacy evidence).

Have been considering transplanting some red alders as nurse trees in our chestnut polycultures but the conditions seem awfully dry in summer for alder up on the hill where the chestnuts will be going.  

This answer may be too late to be of use to you, but I have red alder growing here in central california, within a few miles of the coast. It is in shade at ground level almost all the time, but does not get water from March to November most years. I would think the gulf islands at their driest are more moist than here. No creek or anything nearby. I know they prefer moisture, but I suspect red alder can tolerate anything chestnut can tolerate.

I seem to remember reading somewhere that it was traditional in Sweden to feed the livestock nothing but alder tree hay for a short period (I think a week) in late winter/early spring, to rid them of parasites. But since I can not for the life of me remember where I read that, I don't know any more details (like what parasites, what specific animals, etc.) Arrgh...

Otherwise, alder bark has been used for dyeing, and as an addition (but not on its own) in bark tanning. In both cases it gives a red colour. The bark also seems to be useful medicinally. According to a nice Swedish useful-plants book I have (Vilda växter som mat och medicin, by Stefan Källman) it's used for throat infections and on wounds, primarily as a decoction for gargling and wound-wash. Apparently some unspecified Native American group also put chewed alder bark directly on wounds.

Interesting about the tree hay and parasites. I wonder whether it is killing parasites already in the livestock - maybe from tannins in the leaf and bark? Which seems to make sense based on the use in tanning. I imagine there are trees with higher tannin levels (oak?) but perhaps don’t leaf out so early in spring.

Or maybe part of it is reducing exposure to parasite intake by preventing grazing while the ground is wet. Probably good for the growth of the grass to protect it from grazing for that extra week too. Where I grew up in southern Ontario it was tradition to turn the cattle into the field on Victoria Day which is the third Monday in May, so the ground could dry out and grass would be well established first. Tomatoes were transplanted out that weekend too.

I imagine alder leaves would be an excellent spring tonic for livestock too.

This line of thinking is convincing me to cut alder for our goats next spring. I would say take the goats to the alder woods but it will be too wet underfoot for their delicate and spoiled little tootsies. They would far rather send me in my rubber boots with clippers.

My impression (though it could be wrong) was that alder contains a more specific substance that kills the parasites. If it was just tannin, willow and spruce both contain more. (At least I think so. I attended a tanning course once, and we used both willow and spruce bark. Alder was mentioned as an additive for colour, but not a tannin source in its own right. But again I could be wrong.)

Also, the book I mentioned above says that some scientists in Alaska isolated a substance with insecticidal properties, and another that acts like a neurotoxin, from alder (unclear what species or part of the plant). Sounds about right for getting rid of parasites, but may be a reason for caution if you want to eat it yourself. That said, I did nibble the leaf buds in spring, without apparent ill effects, but long-term, who knows?

Eino Kenttä wrote:My impression (though it could be wrong) was that alder contains a more specific substance that kills the parasites. If it was just tannin, willow and spruce both contain more. (At least I think so. I attended a tanning course once, and we used both willow and spruce bark. Alder was mentioned as an additive for colour, but not a tannin source in its own right. But again I could be wrong.)

Also, the book I mentioned above says that some scientists in Alaska isolated a substance with insecticidal properties, and another that acts like a neurotoxin, from alder (unclear what species or part of the plant). Sounds about right for getting rid of parasites, but may be a reason for caution if you want to eat it yourself. That said, I did nibble the leaf buds in spring, without apparent ill effects, but long-term, who knows?

Interesting! I really want to know the answer to this so I will continue to dig… in the meantime I did find a couple of interesting things, including a document about traditional meadows in Sweden that said alder swamps had been cleared to produce wet meadows for cattle. I also found a paper about traditional herbal livestock medicines in Latvia that didn’t mention alder but did say that high tannin plants were used as wormers. And this one, which says nothing about worming but gives some info about coppicing alder and willows for feed production.  http://www.europeanagroforestry.eu/node/1727

https://ehq-production-europe.s3.eu-west-1.amazonaws.com/d41aca372b996a842e1a1756f10c3e7b24993f74/original/1626951236/3afa22181b89b379569ccc3b2f6798ea_Benefits_of_Farming_with_Trees_LW_03.11.20.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA4KKNQAKICO37GBEP%2F20221128%2Feu-west-1%2Fs3%2Faws4_request&X-Amz-Date=20221128T225355Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=31febaac95d0e6eb7f616262b3380f59a0d64223a7ccf07250a9f35de8e437c0

Sorry about the insanely long URL. It is a writeup on agroforestry from Cornwall, worth reading. This one mentions that the least palatable tree hay, alder, was fed earlier in the winter. No mention of parasites.

Since reading "Sproutlands" about coppicing culture, I've been looking at the power cuts in my neighborhood. They are filled with coppiced wood! Lots of alders in one place, poplars, oaks, maple. In the olden days, coppiced wood was popular because it doesn't take a big saw (or chain saw) to cut it. As firewood it doesn't have to be split, a big advantage. I'm looking at some of these poles for tool handles and other crafty things.
The book on coppicing looks good! Put me in the drawing!