Walipini advice needed

I,m looking for Walipini people , where can i find them on the forum , tentative thoughts on building one in a depression that faces south .

Thanks

Malcolm Thomas wrote:I,m looking for Walipini people , where can i find them on the forum , tentative thoughts on building one in a depression that faces south .

Thanks

Does the depression collect water from the surrounding area?  Make sure you redirect that flow, if so.

Dont think so, its free draining about 20 - 25 feet above the water table maybe a tad more . Water is always a problem here , either too much or not enough. I dont want to fill it in as it would take truck loads of soil and what would i be bringing in  so i thought utilize the land shape and thats it.Will try and get some piccies

This is as good a place as any Malcolm. What questions do you have?

Well , loads !. Back in the mid 80s  i built a cold frame it was about a metre square by about 8 feet long with a pull and flip top and it worked a treat and in London UK as well where temps arent great, but a walipini is a very different beast !!! so i get the feeling its a cold frame on super steroids.
I dont want to do much earth moving , just for the moment utilize the natural banking the highest bank at its peak is about 10 feet when i,m in the dip this faces south.
The opposite north facing bank goes from 2 feet to about 4 feet and the distance between the two is about 7-8 feet. However i will have to chop some small scrappy oak trees that are growing in the dip 6-8 inch dia.
In front of the banks ( to the south ) there are about 20 oak trees smalish that give dappled shade, could be a problem?, across the banks . These i dont want to chop.

I,m thinking, a semi permanant wood frame structure one that could be moved and re built if need be .

3 or 4 verticals from the centre line of the depression will form a shallow pent roof that gives a good 10 feet head height.

The available Length would be about 25 to 30 feet

Framing at each end for doors and ventilation

The structure covered with durable clear plastic sheet  

How do you think it would function with dappled shade and what crops could i grow, we can get some pretty hot summers here.

To fill the depression in would take truck loads of soil and i would loose a naturaly shaped opportunity.
I have a small wood burning stove i could put in there during winter.

What are your thoughts.

I will have a go at getting some piccies and post them.

However i will have to chop some small scrappy oak trees that are growing in the dip 6-8 inch dia.
In front of the banks ( to the south ) there are about 20 oak trees smalish that give dappled shade, could be a problem?, across the banks . These i dont want to chop.

Hi Malcolm,

You have painted a great descriptive image here. These oak trees to the south, could you prune side branches to allow more low light in as the trees grow up, OR, prune out the tops to help them bush outward, so that they actually hold more heat ( also known as "less cold") around the structure?

The small scrappy oak trees IN the dip, can you prune the branches but leave them there as however-high-you-can-allow sticks, for beans/tomatoes/vines to grow on and up, or even to hang your coat on them in winter?!

Yeah thanks for the reply mate , its the trees , i dont like chopping my trees and had thought about incorporating them into the idea of design. If i wipe em out i could loose an option , this is a great thought moment and walk around and visualize options before committing.
As for pruning yes , just have to get the tall ladder out . I gotta think about this one .
I will have to break out the camera and fight with technology and post some pics.

Are you in QL ?

hi fella . north or south london . i knocked around edgeware , many moons ago.
you want a wilipini green house . but you dont want to dig . thats a tough one. i may have it wrong . but i figured that the main feature of one of these is the digging of the hole.lol
for sure take two picks from ether end and draw a plan as you see it . lay it under the kitchin light and take a pic of it well lite. pop all 3 onto the desktop of your computer. then use the attachmants option under post reply ( i think). attach the pics and make the post. jobs a good en and we all know what we are working with.
im on the same jorney as you mate . only im still digging the hole.

Facebook has a thriving group on that topic.    Look up "pit garden"   I left facebook, I may have to create a group on MeWe...

Thanks

Will look up face book pit garden
East London area goodmayes / romford, Essex. Well i dont have dig a hole all i need to do is chop out some scrubby bushes install a roof and two ends then either direct plant into the banks or form into the banks small deep beds or terracing . We do have a problem here with wild pigs and deer , some folk might want to knock em off and stick meat in the freezer but i,m not one of them .
When the batteries charge up i will take some piccies .

I’m contemplating a roll back plastic so my Walipini opens up in summer. The shade could help growing heat sensitive crops. The leaves falling off in winter should help heating. I’m also thinking of building my south wall with a wire mesh then filling with compost. More for insulation then compost or heat, but who knows, maybe it will make a great bed for mushrooms.

Yes i looked up pit gardens . An underground greenhouse , hmmm if i stuck a stove in there i could live in it , rekon it could be fairly temperature stable all year round .

im hopeing to put a rocket mass heater into my greenhouse . itll release the heat slower then a stove. being sunk into the ground by 2m, it should maintain a higher average temp . then i got the heater for when it gets realy cold . the problem with these greenhouses isnt the heating as such , its the insulation. the heat will be there in the ground . the trick is trapping it.
im building on the cheap and have gone with two clear tarps . one is good enough to keep the rain off . but if i want to trap the heat in the middle of winter . ill need the second one . not the best material to use . but the cost of plastic sheeting doubles and then some more then the cost of two tarps . that and the plastic sheet idea i only calculated for one layer of roof.

Malcolm Thomas wrote:Yeah thanks for the reply mate , its the trees , i dont like chopping my trees and had thought about incorporating them into the idea of design. If i wipe em out i could loose an option , this is a great thought moment and walk around and visualize options before committing.
As for pruning yes , just have to get the tall ladder out . I gotta think about this one .
I will have to break out the camera and fight with technology and post some pics.

Are you in QL ?

You know what they say, break eggs, make omelette. Find some nice goats to give the pruned pieces too, get some animal interaction energy healing. Or feed them direct to the ground and enjoy future microbial action.

QL, QLD, queensland, the queens land, terrible name for a piece of Oz, a country that has no treaty between the invaders and the Indigenous peoples.
If I built a greenhouse, or Walipini here, it would be to grow durian and mangosteen fruits...they grow on the coast 2hrs drive for me but I am 850m high.

If your oaks are like my oaks, they hold onto many of their dead leaves all winter.  Thus they provide heavier shade in winter than a traditional deciduous tree.  I'm guessing that at your latitude you'll need every bit of sun you can get in the winter if you want to grow through the year.

Malcolm, you mentioned London. Are you still there? Getting to the root of the issue - what's the latitude where you want to build this?

Latitude is an important factor with walipinis, because if you're far from the equator then your winter sun angles will be so low that the wall on the sunny side  will cast an extremely long shadow that may consume most of your potential growing space.

For example...

I'm currently about 46.88 degrees North latitude

At solar noon on December 21, the sun here is 19.7 degrees above the horizon. This means that a south wall of a walipini that's only 5 feet high will cast a shadow 14 feet long. If I have a 16 foot wide walipini, only 2 feet of it gets any sun at all, and only then at the absolute peak point during the day. (For those inclined toward useful units, a wall 2 meters high casts a 5.9 meter shadow.)

At solar noon on March 20, the sun here is 43.1 degrees above the horizon. Now the shadow of that 5 foot wall is only a little over 5 feet, and 11 feet of my 16 foot wide walipini gets sun at the peak point during the day.

London is about 51.5 degrees North latitude, so it will be a bit worse than the figures above... lower sun angles and longer shadows. On 21 Dec the shadow of a 2 meter wall will be around 7.5 meters.

So if the intention is winter growing, walipinis work much better closer to the equator. At a higher latitude you may be better served with a different approach... (unless your site is already on a significant south facing slope so your south wall can be very short).

If you want to duplicate the above calculations for your location, these tools will be useful...

Sun angle calculator, here, will tell the angle of the sun for a given date, latitude, and longitude. Set the "time basis" to "solar time" and then check at noon on 21 Dec, 20 Mar, 21 Jun, and 20 Sep to get a good picture.

Triangle calculator, here, will help you calculate the shadow length for a given wall height and sun angle. Set angle B to 90. Set angle A to the sun "altitude angle" that you got from the sun angle calculator above. Set angle C to 90 minus your sun "altitude angle". Set side BC to your wall hight on the sunny side. Set sides AC and AB as blank. Then calculate. The shadow length will be side AB.

May your days be long and beautiful, and your walipinis enjoy low latitudes.

Thanks for the reply and the calculators . No not in London anymore !!!.
Now at Lat  42.5000 extended growing seasons, hotter summers much like England in winter , NW Spain the green corner.