Swales to support a dense hedge?

I am leaning on  https://permies.com/t/66024/Swales-heavy-clay-soil

I have heavy clay soil.

On a north facing slope, we would expect swales to on average run east-west, but landscape could provide features such that a swale happened to  north-south for a "short" distance.  But, lets say the swales are mostly running east-west.  If a person was to plant a row of trees on the berm (downhill) side of a swale, that row of trees would be running east-west as well.

As part of a deer/wind control strategy, I will have a dense hedge running north-south (the wind being more or less from the west).  The distance between plants in the hedge is smaller than a swale can be, so there is no way to have a swale "cross" the hedge.

What I am looking for, and so far not finding, is some "rule" on how close one should bring water to the centre of a tree.  The tree to be planted as a seedling, so it will direct its roots to grow as it knows best.  Whatever that is.  I am thinking that the appropriate distance for a 1 year old tree of most species might be as close as 12 inches, but as the tree gets older, you probably want to fill in some of the swale closest to the tree.

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Perhaps a simpler problem to start with.

The largest trees I have planted so far, are (potentially) Bur oak.  This seems to be a tree which is about as wide as it is tall.  My oldest Bur oak has been here 2 seasons, so it is 3 years old.  It hardly grew this last season, as I understand things it is spending all its energy building a root system.  People might plant a Bur oak into the berm of a swale, which would put the oak maybe 5 feet from the water in the swale?  And that would never change, the tree would do what with its roots?  I suspect it might send some roots deep below the swale to the other side.  But at times those roots would be in soil saturated in water.  Certainly more so than a tree planted just in a field.

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On to the more difficult problem.

Having spent too many years doing math, the following is a "rule" I made up with no theory to justify it.

I am expecting the hedge to get to about 20 feet tall (certainly more than 13).  And the plants should be about 6 inch diameter at that point, but will get thicker with additional time.  By and large, if one assumes that the plant is "square" (as tall as it is wide), it is a place to start.  So, the plant is 20 feet tall and 20 feet from dripline to dripline (perpendicular to the line of the hedge).  Perhaps the diameter of the plant when it gets to 20 foot tall is the scaling factor for distance, so the plant is 40 "units" wide.

I have no reason to pick a scaling law of the 1/2 power (square root), but the square root of 40 about 6 and 1/3, and converting 6 and 1/3 units to distance, I get 3 foot 2 inches.  So, I build my swales to come to 3 foot 2 inch away from the trunk when it first hits 20 feet, which would be 3 foot 5 inches from the centre of the hedge.

A couple of years later, I find the hedge plants are now 9 inches thick.  Perhaps the plants are now 22 feet wide.  The plant is now 29 1/3 units (a unit is now 9 inches) wide, and using my scaling law I see I want the swale to start at 5 foot 1.5 inches from the centre of the hedge, instead 3 foot 5 inches.  So, perhaps I should fill the 1 foot 8.5 inches of swale closest to the hedge line?

Comments?  References to papers on this?

Have a great day!

I'm not qualified to answer your questions as asked, but I do have some points for your overall plan re - deer proofing specifically.

Here in the UK hedges are common and historically were the primary means of making stock proof barriers in many regions. The key to making a stock/deer proof barrier is ensuring that stems are densely interwoven at ground level. Untended hedges tend to grow taller, shading the lower regions which inevitably get very gappy as time passes. Farmers periodically (on an 8 to 12 year cycle typically) "lay" the hedges by cutting, bending and weaving living stems from vertical to nearer horizontal. The laid hedge resprouts vigorously, but is stock proof low down. A skilled hedge layer working on a well maintained section of hedge typically would lay 10 to 20m per day. On a hedge that has been allowed to get out of cycle it could be as little as 2 to 5m per day, and might need power tools like chainsaws.

Hedge laying images

Hi.  Thanks for commenting.

As far as qualified goes, I don't think I am even qualified to ask the question.    If you have ideas, by all means present them.

The hedge that I have studied the most, is "hedge" of the Great Plains before barbed wire.  Sometimes called hedge apple, a more proper name is Osage-orange.

I had read that some people did as you suggest with Osage-orange.  I think more people did not do what you suggest (but I have no proof).  I think the people who followed your plan back then, ended up with a hedge that was about 5-6 feet tall, and was possibly 3-5 feet wide.  Which is about the same height as a barbed wire fence is today.  I don't recall ever seeing any comments about the Osage-orange hedge keeping deer out, and at that height, deer would always be able to browse the hedge (even though the thorns supposedly are mostly near the leaves).

There were reports of Osage-orange planted such that trees were 9 to 12 inches apart..  It is entirely possible that some of those trees died.  I believe I ran across one report, talking about the cutting down of a mature Osage-orange hedge, and getting something like 2500 fence posts per mile of hedge.  Which works out to around 2 foot between trees.  It is hard to see how a hedge with trees 2 feet apart would be "pig tight".  But in terms of recovering fence posts from a mature hedge, I don't think that would allow for the type of hedge you describe either.  Maybe a person could get fence posts from the weaved branches and trunks of such a hedge?

As I understand things, regardless of how the people of the day produced their hedges, I think the reason why they were abandoned when barbed wire was invented is to get away from the pruning and other maintenance of that hedge.  For me, I am wondering how one might build a robot to do maintenance on the hedge.

This article explains in detail how to make the osage orange hedge.  I just started a section of this, but I only plan on "working" on it for the first two or three years.  After that it can do as it pleases.  The pictures help show how it becomes "pig tight"

Humble Hive - Osage Orange Hedge

Well, that is certainly "a" way to make an Osage-orange hedge, and it probably demonstrates what Michael Cox from Kent said.  It was interesting to read about incorporating mulberry into the hedge.  I had read about incorporating honey locust into the Osage-hedge, but no specific details on that.

A year or so ago, I corresponded with an "architect" who was involved with the Osage-orange hedge at the Homestead National Monument (in Nebraska?).  Their hedge is of the "row of trees" form, and they are in the middle of fixing (maybe they are done?) the hedge.

There is a fair amount of documentation on an Osage-orange hedge that is in a "crater" in Australia.  They are trying to renovate that hedge as it is a cultural heritage site.

The way Michael is talking about is traditional hedge-laying.  To do it, you cut part way through each plant, bend them over and "lay" them, sometime in a fairly intricate manner of weaving them.  It's quite beautiful and, in my mind, an art form.  The way described on the Humble Hive site, and the way I am doing it, is much cruder.  You just bend the sapling over and fix the top of it to the ground.  Branches from these bent over saplings grow straight up.  The next year, you weave the branches together.  It seems to me to be much easier, but the result is not the beautiful hedge you get from the traditional way.

Regardless of all that, I'm sorry I don't have an answer for your original question about distances from the swales.  I'm not nearly that precise.  I kind of just plant things and see how well they do.  Not necessarily the most efficient way, I know :)

I am not looking for the distances between swales, and I suspect that the answer to this will be in a sense random for my situation.

I want to know how close the swale should come to a hedge that is not parallel to the swale.  In my situation, the hedge will be about perpendicular to the swale(s).

It seems reasonable to expect that this distance changes with changes in the trees which make up the hedge.  If the dripline moves, perhaps the end of swale has to move.

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I guess I have another swale question.

An Evan's cherry is a small tree ([possibly could be under story?).  Ideally, I guess it should go dormant before the ground freezes.  August in many places does this.  Where I live, we sometimes get a fair amount of moisture in September.  If a person build the swale with a "dam" at some point away from the cherry tree, then in September I could open the dam, so that if it rained, that swale would not impound water.  Are there other trees that this sort of thing also should be done for?