To plant above, within, or below the swale?

I live in central Washington state, a temperate climate with snowy winters and hot dry up to 100F summers. Sometimes no rain for 3 summer months and the rest of the precipitation is mostly all winter snow aside from occasional drizzles with rare rainstorms. About 25” per year of precipitation. I am building swales across the 2.5 acres with a mattock and shovel.

The greatest philosophical debate within my mind is whether to plant trees and seeds and things on the land uphill of the swale, within the swale, on the berm, or at the downhill base of the berm? So much variety of opinions out there, I’d just like to see what people think for this particular climate.

My goal is zero supplemental irrigation, minimal inputs, play the slow game, and grow high calorie foods.

Looking forward to responses. Thank you in advance.

In my dry desert climate during a thunderstorm, the whole soil surface lifts up, and moves downhill during runoff. Therefore, I don't plant in the bottom of the swale, because I'm constantly moving soil from the bottom of the swale to the berm.

If I plant trees along a berm, I plant them below... Because the water moves downhill through the soil.

Would it ease your mind to just do all 3? You'd have the bases covered as well as you can for whatever conditions come, with that approach.

Consider the most favorable setting for the type of plant chosen and stick to that for the majority of them tho to try and prevent large losses.

For example, the willows and sycamores I put in the swales have all survived, but I've lost some of those same species in other non-sunken areas because two consecutive rather dry summers.

Shade is a big factor too. Plant some fast growing (or just let the weeds surround) things to protect the baby trees no matter where they are. I also think this keeps mice and rabbits from finding them so easily. For the baby trees planted closer to my dwelling, every so often I pull weeds right around them and use that as mulch, checking for cracked in the ground around them (exposes roots to air, they don't seem to like that) and try to scratch up some soil to fill that in. It really does help to hit with a little water here and there that first and second year if conditions are real dry. I forget where I've planted many, and yes they die but I'm also surprised sometimes when I find one has made it!

Hope this helps, I'm learning too and just trying my best.

Observation might be the key factor.  What happens to your swales when it rains?

We make mini swales after planting out fruit trees, not before.

I hope you will find the answer that you are looking for.

I tried both, before and after, both worked with peach trees. But i'm on a slope and no clay to stagnate water. Otherwise i might have put them on top. Maybe sending a little phone picture could help people get a better understanding

The top of our swale has the worse soil, so elders there. The side away from the swale, on the swales edge, has a mix of topsoil and the hard pan/clay, so that’s blue berries and hazels. I pepper it all with comfrey. In the swale/ditch itself I harvest the soil/compost, clippings, etc. which I have thrown in to build soil back on the top.

Anne Miller wrote:Observation might be the key factor.  What happens to your swales when it rains?

We make mini swales after planting out fruit trees, not before.

I hope you will find the answer that you are looking for.

how do you build the swales? above/ below the trees? can you send a pic? and what is your climate/rainfall like?

thanks
Sandy

I learned over the past couple years of experimenting here in central Washington that my soil is relatively sandy, and since we get minimal rainfall in the growing season, the only substantial runoff happens off impermeable surfaces (roofs, roads, etc), so making water catching swales is ineffective for watch catchment purposes. I would plant things in sunken beds to shield from evaporating winds and to take advantage of any small amounts of precipitation, though. For dryer areas like this I would plant within the swale basin, in wetter areas I would plant beyond them, or on top if the water pools up and could cause root suffocation. My 2 cents..

I live on the other side of the continent, catty-corner from you, but I have a very similar climate. Our oldest (and largest) swale was dug almost four years ago. I left the bottom of the swale unplanted, planted the berm, and left the upper side as is. My observation is that if you don't plant it yourself, nature will do it for you. Some of what I planted on the berm has thrived, but some things didn't make it. Nature was quick to fill in the gaps. So I guess it depends on whether or not you're happy with nature's choices.

I like the conversation going on here.  I guess if I had to give an answer to that specific question—above, within, on top, or below, my answer would an enthusiastic “Yes!”  

But obviously that means that I would plant different plants in different places.  As Joseph mentioned, I would place trees and other deep/rooted perennials below.  I also agree with Kate that nature will plant something somewhere as long as soil and water are available.

Maybe step back and think about what plants would work best in your area.  I think I would want something above the swale to slow down water into the swale and prevent erosion.  Further, I would never want a swale that had nothing in the bottom of the swale.  I would want something to at least hold the soil in place.  And of course, the real purpose of the swale is to hold water to hydrate just below.  That can be all sorts of things but trees jump out as something great.


Just my thoughts,

Eric

S Smithsson wrote:

Anne Miller wrote:Observation might be the key factor.  What happens to your swales when it rains? We make mini swales after planting out fruit trees, not before. I hope you will find the answer that you are looking for.

how do you build the swales? above/ below the trees? can you send a pic? and what is your climate/rainfall like?

My climate is desert/drought.

Swales a below trees? if that fits? so water flows into them ...