# Grow Your Own Food Easier with a Greenhouse

- Link: https://greenlivingguy.com/2016/06/grow-your-own-food-easier-with-a-greenhouse/
- Published: 2016-06-10T05:09:55-04:00
- Author: greenlivingguy

Getting started with growing your own food can seem pretty daunting at first. So
figuring out what grows in your area, how to plant things, what to put where. For
there are a lot of things to work out in the beginning. However, one thing that 
always makes things easier is having a nice, warm space to get seeds started and
protect plants from frost before you plant them in the spring.

## Greenhouses are the way to go

Greenhouses can extend your growing season. In addition, they can keep you from 
having to purchase baby plants from a nursery. With a warm, sunny, protected place
to get plants going, you can get things going earlier. I mean and even harvest more
food.

Of course, greenhouses only go so far. These are essential big glass bubbles, designed
to harness as much sunlight as possible and provide a frost barrier for delicate
young plants. The problem is, glass isn’t the best insulator, so your climate has
to be fairly stable for it to be suitable for plants.

If you have temperatures that still dip below freezing in the spring, you may have
to rig up some additional heat sources in your greenhouse, or even wait to put plants
out there. Some greenhouse kits make it easy for you, but more often than not, insulating
and providing additional heat sources comes at an extra cost.

### Underground Greenhouse

Your best bet for really extending your growing season without paying a big fat 
electric bill in the spring months is to instead build an [underground greenhouse](https://permies.com/t/46532/Greenhouse-Future).
These structures not only give you the chance to get your own seeds started, but
can extend your growing season to year-round, even in the most unforgiving climates!

Now of course, when we talk about underground greenhouses, we’re not talking about
a cave with plants in it. For these things are far from dark. Moreover, it can let
the light in via a glass roof or a south facing set of windows. Thereby depending
on what you’re working with.

### Heat Storage Works in Underground Greenhouse

First, let’s think about how heat storage works in an underground greenhouse;

 1. The sun comes up, and shines through the windows into the earth walls and floor
    of the greenhouse.
 2. The earth acts as a thermal mass, holding onto the sun’s heat and helping regulate
    the internal temperature of the structure even after the sun goes down.
 3. As the air in the greenhouse cools, the earthen walls and floor slowly release 
    the heat of the day.
 4. Over time, this creates what is known in some circles as annualized thermal inertia,
    in which an annual cycle of heat flow is created within the greenhouse.

These structures work in pretty much any climate, with a few modifications. That’s
the thing with a dug-in greenhouse – there is no one size fits all kit, you have
to make adjustments according to your climate and location.

For instance, if you have an extremely rocky plot of land, digging down is probably
more trouble than it’s worth. Additionally, if there are things in your soil that
you’d rather not churn up, like from local mines, it’s nice to take some clean top
soil and instead bury a greenhouse on the surface with bermed walls.

## **Adding a Heat Source

If that big hunk of earthen thermal mass isn’t quite enough for what you’re growing,
[electric heaters](https://morningchores.com/rocket-stove-plans/) aren’t your only
option. Using a [rocket mass heater](https://richsoil.com/rocket-stove-mass-heater.jsp),
you can heat the inside of your subterranean greenhouse extremely effectively, with
very little wood to boot.
[⌊image⌉](https://i0.wp.com/greenlivingguy.com/wp-content/uploads/2016/06/wp-1465535106079.gif?ssl=1)

Rocket mass heaters are a simple design that works so effectively by utilizing the
heat from the exhaust, rather than just the fire itself. You just run the exhaust
piping all over your greenhouse, encasing it in a mass if you like (maybe a pretty
cob bench!), and then run the end of the exhaust pipe out of the structure.

Be careful with rocket stoves though – these things pack a powerful punch, and can
quickly heat up a room. Use them sparingly, and always keep an eye on how hot things
are getting in there.

[⌊image⌉⌊image⌉[

### **Creating Humidity

Having a heat source can quickly dry out the air in a greenhouse, so if you plan
to supplement your underground greenhouse with a rocket mass heater, it may be a
good idea to start thinking of ways to add moisture back to the atmosphere in there.

In a lovely book about a couple’s journey to [off the grid](https://greenlivingguy.com/2019/09/off-the-grid-alternative-housing-ideas-for-independent-living-2/)
living – Off On Our Own – the author Ted Carns details their own dug in greenhouse,
and how they actually put a hot tub in the room, built right into the floor – talk
about cozy!

You could even go so far as to integrate these systems further, not only using the
rocket mass heater to warm the greenhouse, but running the heat source around a 
barrel or two of water for your hot tub for an off the grid hot water heater/greenhouse
heater/humidifier triple whammy.

#### **Core Design Elements

While every setting is different and will likely demand a different set of specifications,
there are a few things that are pretty standard across the board you’ll want to 
keep in mind when creating your underground greenhouse plans:

 1.  Always capture southern sun – You’ll get the most sun exposure from the southern
    path of the sun, so make sure to plan windows accordingly if you’re not doing a
    transparent roof. South facing slopes are ideal for building underground greenhouses.
 2. Insulate the roof – as long as you’re not using it to capture sunlight. If you 
    are, plan on losing quite a bit more heat than you would otherwise. Remember, heat
    rises, and transparent materials aren’t exactly insulative.
 3. Use the roof to capture a water source – Regardless of your window placement, your
    roof can be an excellent way to supply a water source right on top of your greenhouse.
    You can either do a simple rainwater catchment gutter system, or if rainfall isn’t
    prolific enough, create a [radiative rooftop airwell](https://permies.com/t/56129/article-airwells#469568)
    to capture condensation instead.
 4. Redirect cold air – To keep the plants happy and your internal temperature stable,
    it’s wise to build a cold sink into your greenhouse as well. This is basically 
    a narrow channel dug in to the greenhouse, often below a walkway, that allows cool
    air to sink, and keeps it away from the plants.
 5. Leave your walls bare – don’t cover them in anything but earthen plasters or cob.
    Remember, you’re capitalizing on that mass to hold onto the sun’s heat – hiding
    it underneath wood paneling isn’t going to do you any favors. Seal it if you must,
    but let it be a big, dense wall of dirt.

### **Hands On Learning: How to Build One**

I wish I could give you some step by step tutorial on how to create one of these,
but in truth, all I know is what I’ve read in books and spoken to permaculture experts
about in the past. There are no comprehensive tutorials detailing this process on
the web, and it’s still a pretty fringe concept, even for dedicated gardeners.

However, I do highly suggest reading Mike Oehler’s **The $50 and Up Underground 
House** – his designs incorporate a greenhouse on the south facing side of his home
designs, and the concept is very much the same.

There are also a few video resources on the subject – this “Greenhouse of the Future”
one is particularly well done, rich in information, and the end result is a beautiful
earthen jungle room that’s one part sanctuary, one part food production machine.

Otherwise, your best bet in finding an education that covers underground greenhouses,
airwells, and rocket mass heaters is going to be taking a professionally taught 
in-person [Appropriate Technology course](https://richsoil.com/pdc.jsp), like the
one we’re about to have with Tim Barker here at Wheaton Labs in western Montana.

The course not only covers passive solar heating and greenhouses, but will also 
feature special rocket mass heater instruction by the master herself, Erica Wisner.
This course will take place this summer, so if you want a spot, get it now.

Other than that, if you can’t make it to a class, it’s time to start playing around
in SketchUp, rent an excavator, and get to work. Though figures vary by climate,
these greenhouses have been known to maintain an internal temperature of 40 degrees
in 20 degrees below zero weather – without a heat source.

### **How long is your growing season?**

Would you produce more of your own food if you had the growing season for it?

![author avatar](https://secure.gravatar.com/avatar/df91669667126e1290c21ee0342c386e2da19d588d4d9ca6560bd82ed59a9641?
s=300&d=monsterid&r=g)

 greenlivingguy

 The Green Living Guy, Seth Leitman is an independent power producer, a green living
expert, and Editor of the McGraw-Hill, TAB Green Guru Guides. Seth is also an Author,
Radio Host, Reporter, Writer and an Environmental Consultant on green living. The
Green Living Guy writes about green living, green lighting, the green guru guides
and more. Seth's books range from: # Build Your Own Electric Vehicle by Bob Brant
and Seth Leitman (2nd and 3rd editions) # Build Your Own Plug-in Hybrid Electric
Vehicle by Seth Leitman # Build Your Own Electric Motorcycle by Carl Vogel # Green
Lighting by Seth Leitman, Brian Clark Howard and Bill Brinsky # Solar Power For 
Your Home by David Findley # Renewable Energies For Your Home by Russel Gehrke #
Do-it-Yourself Home Energy Audits by David Findley # Build Your Own Small Wind Power
System by Brian Clark Howard and Kevin Shea # and more green living books to follow.

 [See Full Bio](https://greenlivingguy.com/author/greenlivingguy/) [  ](https://greenlivingguy.com/author/greenlivingguy/)