planting nitrogen fixers:eg: alder; placement within food forest.

While huckleberry picking recently on new logging road, I found that the roadside had some very young, easily transplantable, green alders (alnus viridus).  I am hoping to utilize some of these trees in my food forest, as well as in my intercrop/hedgerow/silvipasture/agroforest that will be bands of shrubbery/coppice/herbacseous plants/trees/shrubs in sun catching and frost and wind deflecting shelter-belts alternating somewhat and protecting areas of grains, potatoes, or smaller vegetables/crops.  This system will be based on swales running roughly east west on a gentle South Facing slope.  

I heard that the Bullock Brothers on Orcas Island have sometimes been planting their alder trees in the same hole as their fruit bearing trees with enough success to continue with the practice.  I think that they were chopping and dropping alder branches as it grew, and eventually chopped the alder completely out of the situation.  The fruit tree benefits from the shelter of the alder, the chopped mulch, and eventually the alder's entire rooting area's nutrients, and eventually it's root pathways as it completely takes over the alder's below ground life zone.

I'm wondering if this is a common practice, or if other methods are preferred?  I'm wondering about surrounding fruit trees with tight groves of alders, or planting alders basically everywhere in the orchard but at a wider spacing to the fruit trees but relatively close to each other, and then thinning them later, or if there are other best practices that are recommended with alder.  I also have access to some carragana (siberian pea shrub), and I'm thinking that I will be using it similarly.  

Any advice?

Any mistakes to avoid?        

That sounds like a great project you've got going there. Food forests are multigenerational projects and a true love gift to the future.

I use  mainly black locust and some caragana and honey locust, all homegrown from seed,  in much the same way  you are planing on using your found alders. I have found the most success when i plant the N fixing nanny tree at a site where a large nut or fruit tree will go at least 1 year ahead of planting the production tree there. I mulch well which also feeds the soil life and spot water as needed.

This jump starts the soil ecology and nutrient cycling  at that spot. There is a reason natural succession follows the same pattern - pioneer trees and shrubs prepare the ground for future forests.

Sometimes it isn't practical to plan a year or 2 in advance, so then i just plant the nanny and production tree a few inches apart at the same time. This works better than planting nut or fruit trees all alone, but not nearly as well as planting the N fixer a yr or 2 ahead. Babies need a nanny.

Building off what Mary said you can plant a number of the nanny trees and slowly chop and drop and eventually chop down most of them. Geoff Lawton talks about stacking functions in time. In this case your nitrogen fixers start as the dominate tree in terms of numbers but then you reduce their numbers over time through chop and drop and eventually just chopping them down. A few are left but most are removed. So in the end you have gone from many nitrogen fixers to a few but lots of food plants.

That's  a good point. Seed grown  nitrogen fixer trees are cheap, fast, and easy to grow. Plant them all over the place close together and then gradually remove ( chop and drop) branches or whole trees as needed. This really improves the soil at very low cost and effort.

Thanks to you both.  This is super exciting to me. (I'm such a permie geek)  I had a feeling that I was on the right track with my thinking.  I seem to recall in one of his Survival Podcasts that Jack Spirko recommended majorly overplanting nitrogen fixers in a future orchard site

I use  mainly black locust and some caragana and honey locust,

 Wow, awesome, Mary.  Do those locust varieties grow wild in your area, or are they naturalized, or did you import them from the U.S..  Do they spread rapidly by seed/birds?  I loved driving through and camping on Manitoulin Island on a trip from Toronto to Terrace B.C., my hometown.  Would it be possible to send me some seed of those locust varieties since you are Canadian?  

I am also going to collect a bunch of lupine seeds locally pretty soon to add to the mix of N fixers.  I'm wondering about planting some on the existing hugulkultur, or incorporating it in future ones, with the idea of it building up a super nitrogen sink, especially as the trees are chopped out.  I figure this will also help stabilize the mound, longer term, with all of it's rooting/and extra woody carbon building up in the mound.    

Other plants to try would be the eleagnus species which include several edible ones, and sea buckthorn (hippophae) if you've got the right soil. All are nitrogen fixers.

I haven't heard of the planting method in the smae hole for trees before, it would be great if you could let us know how they fare! My preference would be to interplant with both woody and herbaceous legumes.

Hi Tomas

Other plants to try would be the eleagnus species which include several edible ones,

I'm thinking that I might be able to get away with eleagnus species, but I don't like their often invasive spreading nature.  I don't want my farm to be the place where Russian olive got established in the valley and became the bane of every cattle farmer, or something.  I read that goumi is not terribly invasive.  Any comments on that or on other possible eleagnus species? --- > I'm not sure, but zone three has it's limits in that species, I think.  Probably only a few varieties; but I'm not sure.  There is a shrub called wolf willow, or silver willow, or silver berry, Elaeagnus commutata that grows near this valley in Jasper Park (might grow in this valley too, but I haven't seen it), [at least I'm pretty sure I saw it there in Jasper] and produces a very nutritious fruit that is palatable when ripe.  The bark was used traditionally for making cordage, and textiles.  I'm into that for sure.  It is also reputed to boost orchard crops by 10% !  Woot Woot.  :)   At least that one is local so that I would not be pointed out as THAT guy, who introduced it.  I read that sea buckthorn has become a problem in part of Alberta, which is my neighboring province.  I should keep in mind that Alberta has a much higher % of disturbed land that would be easily colonized by a heavy producing N fixer.  This valley has disturbed land in the form of some logging activity, as well as ploughed, or disked hay fields where I think it might be a problem.  

My preference would be to interplant with both woody and herbaceous legumes.  

Yes, me too.  I've got alfalfa, red and white clover, wild peas, and vetch growing in the meadow already.  I also have a substantial amount of red clover seed which I plan to spread when I break ground on the swales. Lupines are another plant that I plan to gather seed from this year.  I have a friend with a yard full of it, and I have one huge plant that I started from seed a few years ago, and it is ripening a big load of pods right now.

I loved all those posts! It goes along very well with what I have written somewhere else, that basically we as humans have a tendency to want to plant only what we can save and help grow! No, no! Actually plants are growing in huge numbers, and some will feed others, and it is the same with weeds, just look at all the seedlings after preparing a bed, and at what is left after a few weeks.

So let's sow many seeds of cheap to get trees! No problem if we have to cut some.... I guess if we ask ourselves the question "Do I spontaneously find this idea heart-braking?" It can be a yes when I see that we use such words as babies and nany....

I have planted a local tree at a place where I cannot really water it, but I chose the place... I did not dig into the ground but removed the last bits of a rotten pine. I am sure the new tree is happily finding easy highways for its roots: where the pine had dug before. What I can see abovve ground proves me that it works. (my previous intents are dead, this one is nicely green)

Sounds like you are on the right tract, Roberto. I got my blk locust seed in bulk fom jl hudson seedsman, who is definitey worth checking out for many reasons, and i highly recommend this company.

Seeds cross the border from the US no problem. Trees grown from jl hudson seeds from have wintered over well on  my zone 4 farm, so i think they would do well for you as well.


Blk locust is native to a wide range of eastern north america and is naturalized well north of its original area. On Manitoulin, which is zone 3 to 4,  (it is the largest fresh water island in the world after all, so has more than 1 zone on it), there are groves of blk locust on many zone 3 farms which are over 100 yrs old. It does spread by seed via birds, but this happens slowly. It is not considered invasive this far north.

Lupines are a great N fixer to use as well. I have lupines growing that are descendants of seed i brought back from Sepp Holzers farm in Austria. Way cool,hey.? Definitely a mix of many suport  species contibutes to a healthy soil ecosystem and nutrient cycling.

Eleagnus ssp are great  to include if you have the well draining soil they require. I tried for years unsuccessfully  to establish russian olive, autumn olive,  and wolfberry on my heavy clay soil, which was badly farmed for a century.  It came with a severe hard pan, low organic matter, a severe ubiquitous quack grass (Aka couch grass) infestation, and very poor drainage.

The areas where i have been adding organic matter ( bags of leaves collected in town, cardboard, scrap lumber, rotten logs, chop and drop from biomass plantings,comfrey, etc) for 5 years now can now support some spp that require ok drainage. The best result so far, however, is planting eleagnus ssp, caragana , wild blue indigo, and honey locust,etc on the hugel beds i put in.

Various clovers, alfalfa, vetches, etc are doing well all over the place on my farm and are much appreciated. Comfrey is not a N fixer, but it is a miracle plant in so many other ways.

Blk locust didn't  grow fast for the first several yrs on the hard pan clay, but it did at least survive and grow slowly and my older bkl locust plantings are now growing well. This is a major reason that i love BL so much.

Goumi, unfortunately, won't grow this far north. The invasiveness of russian and autumn olive is generally highly exaggerated.  These are pioneer species whose job it is to heal damaged/ disturbed land. Once they have done that job, they gradually die off as other forrest ssp take over if nature is allowed to follow natural succession.

It is when humans ( and in some areas with really tough growing confitions such as alkaline soil, dry, desert areas, etc) interfere  with the natural tendency for most land to gradually return to forrest that eleagnus ssp can take over. When humans keep disturbing the land with mowing road sides, plowing, over grazing, spraying herbicides, construction/expansion of buildings,etc, it freezes natural succession at the state where eleagnus and other pioneers are needed to heal things, so they step up to do their job.

They just aren't  a threat to the local wild ecosystems where i live, which by the way, are already heavily "  contaminated " with a wide range of introduced ssp that have happily naturalized themselves and most people don't  even realize that they aren't native. Think dandelion, apple, plantain, earthworms,etc.

Hi Mary Yett.

Goumi, unfortunately, won't grow this far north.  

I wonder if goumi could be planted in a large pot and brought in for a few seasons of winters, and then grafted onto another eleagnus like silverberry/wolfberry that is hardier.  I did see online that some people saying that goumi is hardy to -25F, so it might be able to handle zone 3 or 4.  I might be able to microclimate up a few zones or at least one in a hugulkulture sun scoop with a pond nearby on the south side of my greenhouse or house.   I checked out JL Hudson.  Great stuff.     I was unfamiliar with the plant wild blue indigo until you mentioned it.  I looked it up. Seems like a gooder!  

The invasiveness of russian and autumn olive is generally highly exaggerated.  

When humans keep disturbing the land with mowing road sides, plowing, over grazing, spraying herbicides, construction/expansion of buildings,etc, it freezes natural succession at the state where eleagnus and other pioneers are needed to heal things, so they step up to do their job.

 That's my general understanding with most invasives, but I still use caution.

I have taken these alder off the sides of logging roads and they do ok.  If the leaves are already budding, transplant success rate is low..
This is my preferred N-fixer for low swampy areas, next to streams and ditches.  One caution is that alder easily fall down, so plan into the future as such..

One caution is that alder easily fall down, so plan into the future as such..

 Yes, they are essentially as short term compost tree, having a relatively short life span and producing a lot of soil building materials above and below the ground.  I was thinking of coppicing or pollarding the ones that I was going to keep around.  These practices, which promote new growth, keep the trees in a youthful stage, and thus can last a lot longer.  

There is also the 7/8th hacked into method that I saw a video of once, where a person hacks into the the alder (or other easy growing tree planted in a long row, like willow) almost the whole way through, and bend it over using the little bit of wood that is left as a hinge.  The branches that are going upward become a whole new set of trees, and some of the ones below will root.  If the person has a lot of material around to dump on it, the rooting could be encouraged, and a living hugulkulture/hedge would be created.  Either way, it will create a dense hedge via the clones from the branches.

If the leaves are already budding, transplant success rate is low..  

  Perhaps I will wait until the spring, or do a late fall job.

I was up in the huckleberry patch again yesterday afternoon.  I really need to get more of those berries before they are done.  I experimentally yanked on a two foot tall alder on the loose downhill side of the road, and it began to come up.  I figure I could plant some larger ones, if they come up that easy, and then I would have enough roots that even if some of the plant died back, it would still have the vigor to survive.