How far to plant your trees from your nitrogen fixers and other trees in contour rows.

I’m still rather new to gardening, especially when it comes to permaculture systems, so this might be a permie 101 question, so apologies if it is a really basic question.

I want to plant 2 rows of fruit trees on contour on my clay-slope (See pic attached). Between these trees I want to plant berry shrubs and nitrogen fixers. I was thinking of mimosa and seaberry, as both do well here and can root deeply to break open the heavy clay of my soil.
My main question is: when you want to create a self sustaining contour row: how far apart do you plant your trees and shrubs from one another. I’m guessing there is a delicate balance between too far apart that the trees don’t benefit from the nitrogen fixers, but too closely and they’ll choke one another out or deprive e&chitter from the sun.
My terrain where I want to plant the trees is about 70 feet in width (so 2 rows is a total of 140 feet) and the rows could be spread apart about 16 feet, but with a height difference of 9 feet between the rows so they’re less competing for sun.

How many (small) fruit trees would I be able to plant, and how should I space them with the nitrogen fixers?

there are lots of possible strategies that can be used when thinking about orchards and surrounding plantings.  

Remember that there is a time element involved and lots of the soil builders will be gone by the time the fruit trees are full size.

In the beginning you could have all the trees spaced very close together, then start to chop and drop your soil builders as their drip lines start to overlap and they start to compete for sunlight. Every time you cut growth above ground, roots below ground also fall off giving nitrogen and creating more open space in the soil. As the trees increase in size. eventually you might expect all or most of the original nitrogen fixers to disappear as the chopping and dropping becomes more intense and the productive trees start to shade out everybody else.

You didn't specifically ask about it, and maybe you already have some grasp of the dynamics of ways to plant to maximize resistance to pest invasion, disease control, and water distribution, but these things are also important to the process .

When planting small anythings, it's easier to cut out extra trees than to fill in if there aren't enough, so plan to overstack your system. Then it's just a matter of looking at the variety you're planting, the suggested spacings, and then lay out the grid.

bob day wrote:

You didn't specifically ask about it, and maybe you already have some grasp of the dynamics of ways to plant to maximize resistance to pest invasion, disease control, and water distribution, but these things are also important to the process .

Thanks for the tips Bob! I hadn't considered the fact that the nitrogen fixers would be removed over time. Do all nitrogen fixers work with the method of chop and drop, or do they also give off nitrogen via their roots?
I am actually a big fan of seaberries so ultimately I would also intend to harvest the berries for food. But maybe then it's better to just give those a place of their own where they can grow abundantly and use the others just for chop and drop purposes?

About disease control and pest invasion, to be honest I hadn't gotten that far yet. I was thinking about adding borage or comfrey as a chop and drop plant, but I'm not sure if these also have pest control benefits.
I was also thinking of letting my chickens roam underneath the tree rows as a pest control and fertilization. Plus they can eat the fruits that fall off.

What plants/ other methods would you recommend?

First, I am not a primary expert, and you need to be prepared to look at species of trees, their possible diseases, pests, needs.

Most fruit trees don't want any grass for instance, so you'll want things like comfrey, daffodils, etc to totally occupy the space under the trees eventually.  things that contribute to the soil, repel pests,  but don't rob the tree. Fennel is supposed to be good for predatory wasps for instance.


Chickens are great at pest and disease control, I think the ratio is 60/acre, but only after the trees are grown. How will you keep animals away from the young trees?  Your swale type plantings look good for water distribution, and flood type irrigation is a great way to go, but if water is scarce you may need to find an alternative method to localize watering under the roots of the new trees, surface watering creates shallow root systems whereas deep water encourages deep roots. (this isn't as important if you start from seed.)

Since you are on a fairly steep slope there you might consider a net and pan type system to establish your trees.

You will also want to consider how to mulch to create a better fungal dominance in the soil to speed the transition from grass to trees. And the idea of conditioning the soil for a year or two before planting trees can really help the trees to do well when you do plant them.

Sorry I don't have time to add more details, but I really have to get moving now. Hopefully others will add to this.

bob day wrote:First, I am not a primary expert, and you need to be prepared to look at species of trees, their possible diseases, pests, needs.

Most fruit trees don't want any grass for instance, so you'll want things like comfrey, daffodils, etc to totally occupy the space under the trees eventually.  things that contribute to the soil, repel pests,  but don't rob the tree. Fennel is supposed to be good for predatory wasps for instance.


Chickens are great at pest and disease control, I think the ratio is 60/acre, but only after the trees are grown. How will you keep animals away from the young trees?  Your swale type plantings look good for water distribution, and flood type irrigation is a great way to go, but if water is scarce you may need to find an alternative method to localize watering under the roots of the new trees, surface watering creates shallow root systems whereas deep water encourages deep roots. (this isn't as important if you start from seed.)

Since you are on a fairly steep slope there you might consider a net and pan type system to establish your trees.

You will also want to consider how to mulch to create a better fungal dominance in the soil to speed the transition from grass to trees. And the idea of conditioning the soil for a year or two before planting trees can really help the trees to do well when you do plant them.

Thanks Bob! This is great advice!
I had no idea what a net and pan type system was. Just googled it and it seems very interesting! I do wonder how well it would work on steep land though!
As for keeping the chickens away from young trees I would think to use moveable electric fencing and just manoeuvre the chickens around the trees until they are grown enough.