The Nearings’ Sun-Heated Greenhouse

In the first place, MOTHER’s editor and photographer
couldn’t have slept late if they’d wanted to. Why? Because
Scott was up at dawn and spent the next hour (right outside
their bedroom window) splitting wood for the Nearing’s two
wood-burning stoves.

Then, after a simple but hearty breakfast, both Helen
and Scott put in a few hours mixing concrete and setting
flagstones into the floor of the combination
storeroom/garage that they’re currently building. This, of
course, was just a little light limbering-up exercise to
give them an appetite for their lunch (again simple . . . but
monstrous!). After the midday meal, of course, the Nearings
slowed down considerably . . . for them.

Which is to say that Helen only picked a couple of
bushels of late beans from their garden, went to town for
the mail, rummaged through a small storehouse of the books
they’ve written and hauled several boxes of the titles back
to their house, took care of other business, ran errands
over what seemed to be half of Maine,
and — finally — delivered MOTHERS representatives
to a distant airport.

And Scott? With a little help from two or three
assistants approximately 70 years his junior, Scott idly
whiled away the afternoon digging a couple of hundred
buckets of grass and weeds from the Nearings’ blueberry
patch, oversaw the transplanting of lettuce and other
vegetable sets into their sun-heated greenhouse, explained
the finer points of wholistic gardening to a few people,
and otherwise kept the homestead under control. (That’s the
trouble with these vegetarians. They can still do so damn
much at 94 that they make this generation’s 20-year-old
fast food munchers look positively sickly and infirm.)

But that’s not what the following excerpts from the
Nearings’ latest book (they’ve written more than 50) are
all about. These excerpts are about the Nearings’ sun-heated
greenhouse that Helen and Scott use to supply themselves
with fresh green vegetables right through the heavy snows
and frigid winds of a New England winter.

The Nearings really know how to feed themselves well in
a rugged climate without using energy — intensive
gardening systems, as the following snippets from their new
book prove . . . and we hope this tiny taste of Helen and
Scott’s genius will inspire you to run right out and buy
their new $6.95 paperback — Building and Using Our
Sun-Heated Greenhouse — for your very own. It’s worth
far more than its price.

We began our winter gardening in an unheated greenhouse
almost by accident. A small seedling (or seed) got lost
under a bench, and in early January, going by chance into
the ice-cold building, we found a flourishing, lush, and
sizable lettuce plant growing through a clump of dry
leaves. It had survived, unwatered and untended, through
several months of outside freezing, in a sheltered but
chill corner of a cold glassed-in building.

If this could happen, uncared for and unbeknownst, why
could not more lettuces, and other plants, survive, under
better conditions, still without artificial heat? We were
launched on an experimental period of greenhouse building
and planting that has provided us with fresh green things
through thirty winters of freezing and below-zero weather.

Without question, plant germination and growth is checked
by cold weather, and only certain plants can survive. Very
low temperatures will kill almost any growing thing
eventually. But there is a wide margin, and our experiments
pointed up the plants that will not be killed by low
temperatures.

Almost all of our gardening experience has been in the
North Temperate Zone, taking advantage of summer sunshine
when we can get it, and taking cover as cold blasts from
the north and east strip the foliage from trees and crumple
down green crops in the garden. One of our chief aims in
gardening is to find those plants that can remain succulent
and edible throughout the coldest weather.

Timid In The Beginning With Winter Gardening

We were timid in the beginning of our early experiments
with winter gardening. Getting up around daylight and going
into the greenhouse at the point of maximum possible frost
damage, we saw plants of lettuce and Chinese cabbage and
celery, escarole, collards, chard, and radishes limp and
wilted as though their life span were near its end. Going
back a few hours later, after the sun had had an hour or
two to melt the frost on the greenhouse roof and windows,
we found the semi-wilted plants revived, standing up sturdy
and strong.

After a few such experiences we realized that we had
seriously underrated the frost-resistant capacity of
semi-hardy plants. If a greenhouse looks like a graveyard
early on a zero morning, close the door, wait until the sun
has burned off the frost covering, and you may be
astonished to observe the comeback.

Plants Freeze Easily

Most cultivated garden plants freeze easily. A garden of
beans, corn, tomatoes, and squash can be wiped out by three
or four 28 degree night temperatures. Other garden plants
such as Chinese cabbage, some lettuces, and celery often
can stand up against temperatures as low as 20 degrees. For
years we have been able to carry over kale, brussels
sprouts, leeks, parsley, and even spinach in the open
garden if a blanket of snow comes before the deep freeze.

The winter of 1976 — 77 was one of the longest
continued cold spells, with no alleviating thaws, that we
remember. The cold started in November and carried on
through to March. We had to leave our farm early in
December for a lecture trip and did not return till late
January.

We found two broken windows in our greenhouse and one of
the garden gates wide open and frozen in solid ice.
Nevertheless, our sun-heated greenhouse, minus two
broken-out windows, and heated only by a few days of pallid
sun, was able to supply us with:

1. About 100 elephant leeks, still edible and delicious in
mid-February
2. Several dozen celeriac roots
3. Two dozen roots of viable green parsley
4. A score of Pascal celery plants (the outer leaf stems
were frozen, but the growing centers were lively and
green)
5. A dozen small escarole plants that were lightly covered
with dry autumn leaves
6. Several dozen half-grown lettuce plants: Simpson,
Oakleaf, and Buttercrunch
7. Three red chard plants.

This is hardly noteworthy in comparison with the glorious
green that has carried over for us some winters, but it
shows what might be done in a winter greenhouse by
gardeners who stayed at home and took care of their winter
gardening.

We do not recommend leaving a greenhouse without care. We
believe that if it is given daily attention the plants
which it shelters will be in better condition than if left
in total neglect. What we are propounding is the apparent
capacity of certain untended plants to survive in
continuous sub-zero weather.

The simple, cheap, unheated type of greenhouse that we have
evolved adequately protects certain selected greens all
winter. With moderate heat in the garden in summer and
glass protection through the coldest of the winter months,
we have lengthened the season so that we can feed ourselves
year round on growing green things. It is on the basis of
almost half a century of experience with growing lettuce
and other plants in a cold climate that we base our
argument concerning the possibility of year-round gardening
and especially the possibility in a glass-walled unheated
greenhouse.

A Greenhouse Extends the Growing Season

There are many weeks in a New England gardening season when
temperatures hover around freezing. A spring fog or an
autumn haze holds the temperature at or near freezing. We
guess that during the 120 days from April 1 to June 10 and
from August 25 to October 15, our garden may have around
five killing frosts and another dozen mornings with white
frosts on garden paths. Any one of the killing frosts will
eliminate or cripple sensitive seedlings. All of the
near-frost nights will retard germination and growth.

A can, bottle, box, or basket — or even some newspaper
or a light mulch — over each exposed plant will tend to
reduce the frost damage, but a greenhouse provides exactly
the needed protection for everything inside its four walls.
If we have perhaps 105 frost-free days and another 120 days
during which a bit of glass will ward off frost damage, an
unheated greenhouse in our climate belt will provide
adequate frost protection for at least 32 weeks of the
52-week year.

Greenhouses Allow a Variety of Plants to Grow

Our year-round greenhouse continually contains a wide
variety of plants; some more hardy, some less. In it at
each season — spring, summer, autumn, winter — there are plants
in various stages of development. Seeds, tiny seedlings, or
mature plants occupy every square foot of the greenhouse.
Some seeds, recently sowed, are not yet germinated. Some
will make the salad for the day’s evening meal. Some, like
tomatoes or peppers, remain in the greenhouse for months.
All these plants, in various stages, will be transplanted,
consumed, and replaced in their turn. Before the greenhouse
soil gets its next crop of plants or seeds, it will be
reworked, refertilized, and either reseeded or occupied by
seedlings raised in another section of the greenhouse, and
reset in the recently vacated soil.

Each month and season will find some variety of plant life
playing its allocated role in providing the edibles that
make up our daily diet. The sequences are carefully planned
to produce the maximum in food value from each square foot
of greenhouse soil, and all tend to extend the growing
season.

Winter Garden Hazard: Cold Weather

New England wintertime has usually been ruled out as
ungardenable unless it is undertaken in artificially heated
glass houses. Our greenhouse is unheated save by direct and
indirect rays from the sun. Nevertheless we eat out of our
sun-heated greenhouse right through the roughest and
toughest winters. How do we do it? We have learned how to
live with and prevail against winter’s hazards.

The first hazard, of course, is the cold weather. Where we
live in eastern Maine, along the coast, the normal winter
thermometer goes below zero many times each year. Most of
our plants left in the garden crumple up and rot after a
hard frost. Other plants, after freezing, thaw out time
after time. The first task of the would-be winter
greenhouser is to find out which plants will and which will
not stand hard freezing. We have been studying this matter
for the last forty years and are glad to share our
findings.

Winter Garden Hazard: Snow and Ice

The second hazard is snow and ice. Snowfall may be a
problem in its own right; it is certainly an effective
check on gardening. Its after-effects may be even more
serious. A New England snowstorm, driving in from the
northeast, may include rain which melts part of the snow.
If the storm ends by a wind shift into the north, the
resulting drop in temperature turns slush and snow into a
treacherous ice sheet that covers trees, highways, gardens,
and footpaths. Work in the open is brought to a halt, with
foot passengers and drivers alike picking their way with
care, or calling it a time to hibernate.

Equipped with a glass roof, a greenhouse is especially
hampered by snow and ice. A snowstorm cuts off light; it
also adds to the roof load. If the snow is freezing as it
falls, it hardens onto the greenhouse roof and stays there
until it is softened up eventually by higher temperatures.
We aim to keep the greenhouse roof clear of snow. We have a
wooden snow-pusher with a long, light handle. As soon as
snow has had a chance to soften up on the roof we push it
off and let in the light.

Winter Garden Hazard: Frozen Ground and Freezes

A third winter hazard is ground frozen so hard that it
cannot be worked in the unheated greenhouse. This situation
is avoided or postponed by sprinkling, before the ground
hardens, a moderate layer of dry autumn leaves over any
greenhouse earth that is not covered by foliage. A little
experience will show how thick the layer of dry leaves
should be. We know that if lettuce and other such plants
have a light mulch of dry autumn leaves thrown on them it
helps them to survive. Even on a sub-zero night the ground
covered by such a mulch may be unfrozen.

We have checked this point on a bit of land covered by a
thick growth of soft maple, white birch, and pin cherry. If
the normal leaf cover on such a piece of woodland is
undisturbed there will be two or three inches of dry leaves
that can be kicked aside, revealing an unfrozen forest
floor. Unless the ground is water-soaked, the leaves have
curled up and are able to keep large air spaces between
leaves . . . which prevent the ground from freezing.

If any of the soil in the cultivated area of the greenhouse
is exposed, keep it stirred up with a light stick or a
small tool, even when it looks as dry as dust. Really dry
ground cannot freeze; it is the water in the ground that
freezes.

Another hazard is the succession of freezings and thawings
that the plants may have to undergo in an unheated
greenhouse. One or two such experiences may not prove
fatal, but too many might finish off delicate plants. The
foliage of most hardy or semi-hardy plants will survive a
great deal of freezing and thawing unless there are juicy
stems or other exposed parts that get iced up. Deal with
this difficulty by not touching frozen, brittle plants that
may break off before they thaw.

Growing Wintertime Lettuce

We come now to lettuce, which is very important to us
because we use it so frequently in salad making, and go out
of our way to have this tender fresh green for at least one
meal every day.

Lettuce is a rather fussy cold weather plant. During a zero
night the entire lettuce plant is frozen stiff. When the
sun thaws out the plants, those with thin leaf stems
continue green and alive and go on living normally. After
several freezings, lettuce with thick leaf stems begins to
rot. The leaf stems in Oak Leaf lettuce, for example, are
relatively thin. The stems of Simpson lettuce also are
thin; the leaf stems of Romaine are juicy. The Butterhead
lettuces generally have moderately thick leaf stems.

As our experiments have proceeded we have found that
Simpson, Oak Leaf, Green Boston, Buttercrunch, and other
lettuces with particularly dry leaf spines have survived
during our Maine winters. With one exception (the winter of
1975-1976) we have succeeded in carrying some — at
least — of our lettuce plants through every winter.
Almost always they went into winter as half-grown plants or
even as plants still in garden flats.

Our lettuce plants still in shallow garden flats were wiped
out the winter of 1976-1977, while those in beds survived.
Weathermen counted ten distinct storm cycles from the
middle of November 1976 to the end of February 1977. These
storms followed one another closely, without a single thaw
break. In the severest weather the curly endive and
escarole were retarded but did not die. Their growth was
checked but they were not killed by weeks and months of
sub-zero frost.

Growing Escarole in Winter

We would like to refer especially to a bed of broad-leafed
Batavian escarole which we raised in a seed flat and then
transferred to a garden flat. They were three inches high
when moved into a greenhouse bed and covered with autumn
leaves. All of these plants survived the same winter that
killed the lettuce which was in flats.

As we pass this unusually persistent and prolonged winter
season in review, we are pleased we went through it before
we wrote this book. Despite its extreme severity we can
report that we were able to carry a variety of vegetable
greens through one sub-zero period after another with no
thaw in between. Each sub-zero cycle proved to us that our
basic assumption concerning the capacity of succulent green
vegetation to outlast deep freeze is established beyond
question.

Our Fragile Winter Celery

At the other end of the equation is the recognition of the
unquestioned fact that all growing things have their
limits. Celery is more fragile than lettuce. Its leaf stems
are thick and juicy. In the winter of 1976-1977 we had
a bed of celery plants which we had raised from seed, put
into garden flats, and heeled into the greenhouse in the
autumn of 1976. The celery plants took the transplanting
well and went into the winter lightly mulched. We then
entered into the toughest winter in memory. In the course
of that winter this batch of celery was completely wiped
out, but it survived for more than a month with outside
temperatures down to seven degrees below zero . . . and up to
that time showed little frost damage.

Not all Plants Will Survive

It is obvious that all vegetables will not survive a winter
in our sun-heated greenhouse. We selected hardy plants and
treated them as well as we could, and we learned a great
deal during these experiments. We found out that a
homesteading family using a sun-heated greenhouse as its
medium can supply itself on a twelve-month basis with salad
and other greens taken directly from the garden and
greenhouse. If our contention is upheld by subsequent
tests, New Englanders and other cold climate homesteaders
have a means of greatly improving their winter diets
without dependence on artificial heating or on products
imported from Florida, Texas, California, or Cuba.

Winter Parsley Has a Good Chance to Survive

Meanwhile we are continuing our experiments with a greater
variety of plants because we would like to have at least a
dozen greens that will survive the Maine winter in a
sun-heated greenhouse. Our guess is that much depends upon
the water content of succulent leaf stems, also on the
moisture content of the soil in which the plants are
growing.

We know that a parsley leaf with a juicy stem will freeze,
that the cells will burst, and that with the first warm
weather the stem will begin to rot. But please note the
difference between the stem and the leaf webbing. The leaf
web may go on living for days and weeks despite the loss of
the leaf stem support. This fact leads us to conclude that
certain varieties of parsley, lettuce, and other plants-
carefully selected for the relative dryness of the leaf
stems-will survive, particularly if watering is reduced to
a minimum.

The Nearings: Living a Better Life

Through the ages human beings have been searching for a
good life . . . a better life. The current movement to
homestead, to live simply and quietly, in good health, in
clean air, and in the country is part and parcel of that
long-term trend. It is not only a movement for individual
betterment; it implies social change and improvement as
well.

As the determination to live a better life spreads through
the North Temperate Zone, it is being transformed from a
wish or dream stage into concrete social patterns.
Providing fresh green food in a sun-heated greenhouse is but
one example of this advance. A large degree of
self-sufficiency lies within the easy reach of any
homesteaders who have established themselves and who are
ready to put time, energy, and ingenuity into stabilizing
their homestead way of life.

A sun-heated greenhouse is a project that practically any
family can work at and benefit by. The undertaking can
enlarge the possibilities of income. It can extend and
enlarge the variety and quality of food consumed. It can
enhance the homestead itself by an attractive addition to
the home buildings. And it can open up a better life for
its builders and for the country at large.

From Building and Using Our Heated Greenhouse by Helen
and Scott Nearing, copyright© 1977 by Garden Way
Publishing, Charlotte, VT, and reprinted here by
permission. This book is available in hard cover ($9.95)
and paperback ($6.95) from any good bookstore and (in
paperback only) from MOTHER’s Bookshelf.