garden ATI - making warm spots in the garden with ATI

This is something I wrote about six years ago here.  I just want to give this concept its own thread.


The idea is that there are two big things at work here.  

thing 1:  the pond is reflecting water onto a dark, heat capturing surface.   When combined with a low sun, this makes for double heat capture.  

thing 2:  we are using ATI techniques to keep this mass dry and to insulate it a bit.  In theory it will collect a lot of warmth over the summer as well as from a low sun in the winter to make for a much warmer spot.  

ATI = Annualized Thermal Inertia

could the thermal mass under the umbrella be enhanced by boulders or rocks buried under the umbrella and exposed to the sun?

And for those who have ponds that freeze in the winter, snow also reflect well.  So having a flat area of snow to reflect would also help.

It would be really sexy if a natural roof could extend from the mound over the plant a bit.  Not enough to shade it in the summer but just to hold down some more heat.  Or maybe block some thermal losses to the night sky.  Or is that what the small black line extending off the mound is?

big rocks would be an added bonus.   Since we are keeping it dry, I suppose you could even make big rocks (sort of) out of cob.

At the northern border of our place there is a 3 1/2 foot urbanite retaining wall of broken concrete slabs, and old concrete lintels and windowsills, some stone, and for whatever reason (and at the base no less) an old icebox rusting away.
It is all dry stacked so it drains well (not holding back a lot of frozen wet soil).
Our dirt access road runs alongside the south side of this wall, and in the winter the snow melts away 6-12 inches from the base with just a few days of good sun. The roadway snow is a good reflector, and the melting happens more quickly than if the road is bare.

Way down on the list, is improving this area for growing. Right now it is very much a utilitarian space, gravelly, fenced out of the main field, subject to wildlife... maybe daffodils and alliums.
The microclimate there has always intrigued me.

What happens if you can keep the water off of it.  And keep the cold air from moving through it?

It is a retaining wall...so no air is flowing through it, per se. Along it maybe?
There's some soil on top, right up to the top course... and who knows what deeper in behind it? But there is plenty of space in between the face "stones" and directly behind... the chipmunks dart in and out all the time, in one place, out another...
The land on the uphill (neighbor's) side is either asphalt pavement level with the top of the wall (a driveway), or it slopes upward for 2-10 feet then becomes asphalt pavement and farther along a garage. The whole length has 8"-12" Norway maples, some growing out of the wall itself, and some shrubs. I'm not sure if the wall is holding the trees up or vice versa.

So, I don't really have control over the water since it isn't my land... and certainly can't shed it like your sketch does. I might get away with a tarp with a lip to redirect a section down the length of the wall... and bury it under mulch? stone? My neighbor might be up for that.

I could lean/stack some things up against my side of the wall at intervals to create "rooms" along the length of the wall... maybe a stack of cement block (coming 16" out from wall... any more than that and it will be a hazard for driving).

I'll try to get some photos this weekend.

Could you indicate on the sketch where the plant roots are?  Is there a membrane-lined planting hole, or a large planter, or?

Thanks!

Kenneth Elwell wrote:The land on the uphill (neighbor's) side is either asphalt pavement level with the top of the wall (a driveway), or it slopes upward for 2-10 feet then becomes asphalt pavement and farther along a garage.

 Maybe the asphalt would do the job of the umbrella, keeping water from infiltrating from above...

Is there a difference in the materials represented by different colours in the vertical part of Paul's picture?
Are the black lines water barriers?

I believe so.  I think the surface black like is just a line showing the surface.  The two lines under the hill are the two layers of the umbrellas.  The lighter grey the soil is, the drier it is and thus the more insulative it should be.

I use my house for the ATI. One side is oriented in a South-South-Eastern direction. So that wall gets a lot of sun. I made a garden bed there, against that wall. That's the spot for my tomatoes and other heat-loving plants.

Warm spot in my garden (front yard)