Growing year round with an underground greenhouse

Isabel - May 11, 2021

Came across this website and forum after reading some of the gardening articles and am impressed with what I’ve seen so far. Hopefully I can just jump in and ask a question, if not feel free to remove this. 

Have any of you heard of or made a walipini? Also known as an underground greenhouse, pineapple pit, or sunken greenhouse.

Here’s a picture of the inside of one:

As you can see, it’s pretty much just growing things in the bottom of a pit with a clear tarp over top.

There are like a hundred pictures of various designs of underground greenhouses on this page: https://insteading.com/blog/underground-greenhouse/ From very expensive and extravagant models to just a sheet of glass over a hole in the ground.

I’ve grown some plants and vegetables here and there in pots over the years but am getting more interested in gardening. Hence why I found this site.  I hope to make this a fun and rewarding hobby that can help me be a little more prepared. And this seems like a good way to grow things because of the recessed garden being warmed from the earth, and ability to grow even tropical fruits year round in colder climates.

Thank you to anyone who comments

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I’ve had a greenhouse in the past… a regular one.  From my experience, I’d say growing tropical fruits year round in colder climates would be a stretch.  And my experience is in north Mississippi, not the far north.

Here is my take on greenhouses.  The clear panels on the roof, and in a regular greenhouse to include the walls, do a good job of letting in warming sunlight & can make it toasty on sunny, winter days.  So much so, mine had heat activated vents in the roots to cool it off.  The issue has to do with longer winter nights and when you have periods of extreme cold and cloudy weather.  During those periods, the temps inside drop quickly, even if you have some thermal mass.  A cold, cloudy winter day will not heat up much… if any.  Your tropical plants, or most any plant will die.

Even inside your tunnel, the soil will be cold.  Up north, even frozen for a foot or two.  So I really don’t think you are going to get the impact that you think.  My experience is that greenhouses, including cheaper & easier grow tunnels on rows, simply extend your growing season.  They don’t turn an area tropical in the dead of winter.  So I went from a greenhouse, to grow tunnels to nothing nowadays.  I extend my growing season by picking cool weather crops, such as collards, peas, & kale to grow during spring & fall… and in some cases, all winter long here in Mississippi.

I would suggest, as a beginner gardener to stick to the basics.  If you are up north, maybe even play with grow tunnels.  I used pvc pipe to arch over the rows & covered with the special cloth.

Just my 2 cents.

 

Thank you for your advice and recommendations. I only mentioned the growing of tropical fruits because of two things I saw online.

The first was a youtube video of a man growing bananas in colorado https://www.youtube.com/watch?v=6KCOY-LVXmk and the second was a Wikipedia article about pineapple pits where in England they were able to grow a few pineapple https://en.wikipedia.org/wiki/Pineapple_pit. These are probably the rare case scenarios though and I likely will not have the same results just starting out.

I do appreciate your advice, you seem to be very smart in this area. I like the idea of the grow tunnels you recommended! 

 

Here is an old pic of my raised beds with pvc pipe for hoops to support the cloth for the tunnels.

 

How do the hoops stay in place and not tip over?

Looks like magic!

You have a really pretty garden by the way 

 

Thank you.  I use cheap pipe clamps and fasten with wood screws.  You might need to use 2 on each side.  I’ve also clamped on a larger piece of pvc pipe to the outside of the bed, where that the hoop ends slide inside.  I got a wide enough roll of the material so that it could hang to the ground with some spare room.  Then I used those pieces of 4×4 you see stacked in the bed.  I just lay them on top of the material & they will hold the material in place in all but the strongest storms.  If real windy, I’ve hammered in some big staples.  Just don’t hammer them all the way in, otherwise they will be hard to remove.

This pic shows the pvc pipe that was used to hold the hoops in place.

 

Oh that makes much more sense! Thank you for the additional information.

 

Good evening Isabel,

Welcome to the forum.

 

Had to cut short this post yesterday.

Yes, had heard of Waliponi.

It was mentioned in a seminar I attended re using shipping containers for greenhouses. Here in coastal Virginia underground greenhouses cannot be used due to the water level. To get the warmth of the earth requires going 6 + feet down.  This doesn’t work here.

I remember at the seminar that flooding must be prepared for.

The overall sunken greenhouse can be expensive.  Costs and budgets must be researched/established before starting project.

……

Not due to the topography of coastal Virginia but the area’s counties try to tax shipping containers on one’s land. 

 

I never thought about using a shipping container before, that is very interesting. Would they cut the roof off and put in a glass one?

That does sound like one of the big drawbacks of an underground greenhouse, flooding. If it isn’t designed properly, it might just become a giant underground indoor swimming pool

Thank you for welcoming to the forum! I love it so far. How long have you been here?

 

Good afternoon Isabel,

Shipping containers are reconfigured for many uses here.

I have little knowledge on greenhouse use but surely after section of container roof removed, it’s refitted with something for sunlight and appropriate to clean.

Believe I’ve been here at forum for about a year.

Glad to hear you’re finding TP.com valuable to you.

 

A friend of mine has a rocket stove in his greenhouse to heat it over winter. That could be worth looking at. They run on twigs , so very efficient.

https://naturalhomes.org/permahome/rocket-mass-heater-basics.htm

 

I have never heard of a rocket stove before, but that does sound like a nice green way to reuse branches and twigs that otherwise would be considered trash. Thank you for the suggestion, I’m going to have to do some more research on this.