How much garden space do you need?

In my last post, "The Beginnings of our Garden," a reader asked the following: "36 raised beds is a lot of planting space and when you do double that to 72 raised beds that will be a huge resource. I am jealous. But I still have that question I asked awhile back; how much garden space or raised beds is enough to grow a year's supply of food for a family? Would 36 raised beds do it? I do recognize that you plan to have some orchard trees too and perhaps some grain in the future and of course livestock. But to restate the question how much garden space would be required to raise enough food for four people? Not the perfect variety of food or fodder for live stock but the minimum space that would support a minimum but adequate diet."

This is a hard question to answer since literally everyone's situation is different, but I'll give it a stab. 

Self-sufficient gardens differ from regular gardens in a number of ways. The main things you need to consider are permanence, preservability, and quantity. In other words, what you plant in your self-sufficient garden should fulfill three primary functions:

1. Plants you like to eat
2. Plants you can preserve in some non-electric form (i.e. doesn't require a freezer)
3. Plants you can grow in enough quantity to sustain you

For increased food self-sufficiency, I recommend livestock – chickens, goats, cattle, or other meat, milk, or egg sources.  However if you can’t keep livestock, it's crucial to grow plant-based protein sources such as nuts and legumes. Hazelnuts, walnuts, peanuts, and dry beans are some examples of plant proteins. If you do keep livestock, these plant proteins will help round out your diet.

Another component to incorporate into a self-sufficient garden is perennial plants. Berries, fruit and nut trees, asparagus, certain herbs, and grapes are all examples of perennials which will regrow year after year with minimal effort on your part.

In a self-sufficient garden, you should concentrate on foods you can preserve through the non-growing seasons.  If you're overwhelmed with all the lettuce you've planted and there’s no way to preserve it for next winter, it's gone to waste. (Yes, I know you can dehydrate and powder lettuce, but follow me here.) In warmer climates you might be able to keep a garden going most or all of the year, but in northern climates that's impossible. Instead, we simply concentrate on foods that can be preserved, which captures the garden's abundance to last throughout the colder months until the garden starts to produce once more. This means mostly canning and dehydrating. Some people also freeze or freeze-dry, though those methods use electricity so we prefer not to depend on them.

Probably one of the biggest problems is when people underestimate how much food they eat in a year. When planning a self-sufficiency garden, the basic rule of thumb is this: Grow more than you think you'll need. You may be feeding more than just yourselves at some point.

Offhand I would say a quarter-acre of intensively cultivated garden space would likely go a very long way toward supporting a family of four, especially if it's supplemented by chickens, fruit trees, etc. But this is nothing more than an educated guess, and it doesn't include the land needed for grain, fruit and nut trees, and any livestock you have, from chickens to goats to pigs to cows.

The following material is used (with permission) from an article by "Dr. Prepper" on SurvivalBlog.

To help determine how much food to grow, assume the following facts:

•    One pound of beans = ~2000 calories, one 50-foot row produces 5 pounds of dried beans.
•    One pound of corn = ~ 1800 calories, one 50-foot row produces 10 pounds of dried corn.
•    One pound of hard squash = ~ 250 calories, one 50-foot row of produces 175 pounds of squash
•    One pound of potatoes = ~ 450 calories, one 50-foot row produces 75 pounds of potatoes

Divided out equally as your only diet, for an entire year, you would need the following for one person:

•    Beans – 5 fifty-foot rows
•    Corn – 3 fifty-foot rows
•    Squash – 8 fifty-foot rows
•    Potatoes – 3 fifty-foot rows

Assuming one fifty-foot row is 3 feet wide with a 2-foot aisle, that comes to in total in excess of 4,000 square feet of garden (that's a 63' by 63' plot) needed for growing the caloric needs of just one person. Start multiplying accordingly by the number of members in your family or group and you start to see the magnitude of what is needed for a true survival-type garden. It is quite possible that you may need one-half to two-thirds of an acre to feed yourselves. Also, to reiterate, this is based on providing a minimal diet of 2,000 calories per day, which is not a whole lot of reserve for exertion or stress, and this estimate does not allow at all for crop failure or rotation needs, so you really should plan for a larger garden.

What should you grow? There are a few considerations for what to grow in a self-sufficiency garden:

• Grow what your climate will support. No matter how much you might want them, you can't grow mangoes in Alaska. Become familiar with the USDA Plant Hardiness Zone Map, which most seed companies use when listing their varieties for sale. Local nurseries will usually carry what will grow in your area.  You might also talk to other local gardeners to get their advice.

• Grow what your family likes to eat. You might be able to grow zucchini easily – most people can – but why bother if your whole family hates zucchini?

• Grow what gives you the most caloric and nutritional bang for your buck, particularly if you have a limited growing space. Four crops should be in every self-sufficient garden, particularly if you have no calorie sources from animal proteins: corn, potatoes, beans, and squash. All of these food items are versatile, prolific, and store well under the proper conditions. Varieties are available for almost any gardening conditions, so look into what grows best in your area and with your challenges.  Keep in mind relative amounts of harvest. Out of one raised bed, we can grow 30 lbs. of potatoes, but out of that same bed we might get 8 or 10 ounces of dried beans (which contain more protein).

• Most of what you grow should be preservable in some form, whether canning or freezing or dehydrating or freeze-drying or fermenting or cool storage. Remember, if you're overwhelmed with all the lettuce you've planted and there's no way to preserve it for next winter, it's gone to waste.

Naturally all this advice is adaptable for one's particular circumstances, and considering such factors as skills level, pest pressure, space, water availability, physical strength, time, etc. There are a zillion and one different considerations when answering that initial question "How much garden space do you need?", but hopefully this gives you something to think about.

The beginnings of our garden

Several readers have expressed interest in how Don is constructing our garden beds. I suppose it's time for a garden update to let everyone know what we're doing.

First, let's back up a bit. We've lived in our new (to us) home for two and a half years now, and one advantage of delaying a garden is we now have a better understanding of the "traffic flow" of the property. We've also had a good long time to think over how to make things efficient.

Our land is mostly sloped, with a weird pie-shaped wedge of flatness where the house and barn are located. The barn is on the narrow tip of the wedge, and the house at the wider end. The widest part of all is the driveway. For this reason – and also because it's already covered with heavy weed cloth and fine pea gravel for built-in weed control – we initially thought about constructing the garden in the driveway itself and parking vehicles behind the house by the barn.

That's why we put the two strawberry beds where we did – in the driveway, all by their lonesome and boxed in with horse panels draped with deer netting.

But two years of traffic flow and understanding how we use the property have made us realize the driveway has better uses than a garden. Instead, we chose to place the garden on a gently sloped area right beside the yard. The space is long and narrow. (You can see Don at the far end to give an idea of scale.)

Our old garden was made of tractor tires, and it worked spectacularly well. However tractor tires aren't as easy to come by in our new location, so we had to think of alternative (and cheap) ways to create raised beds.

Thankfully the previous owners of the house had left behind a large stack of old sheet metal siding.

This free resource, we decided, would become the basis for our garden beds. Each sheet is 11 feet long and two feet wide. After taking measurements and deciding on dimensions, Don knew he could get one bed from each sheet of metal. To frame the beds, he purchased a unit of pressure-treated 2x4s.

Each bed would take two 2x4s to create.

Don used a Sawz-All to cut the 11-foot sheets to size: Two eight-foot lengths and two three-foot lengths, to make a bed of 3x8 feet and one foot high.

He made a separate frame for each side. The long side has a central "rib" for extra strength.

He learned staples are the best way to fasten the metal to the frames.

Then he screwed the frames together and started stacking them up. He made ten beds for the first batch.

By the way, some have wondered if the sheet metal sides wouldn't buckle or bulge from the pressure of the soil. Well, the two proto-beds have been planted with strawberries since last summer, and they've worked perfectly. No bulging, no buckling.

Then we had to start prepping the garden space itself. In our old garden, we used drip irrigation to great success and knew we wanted to do the same thing with our new garden. So last year we ordered all the drip irrigation supplies we would need.

In mid-May, when the ground was soft but not muddy, we started prepping the garden space.

Using the tractor, Don scraped off the top layer of dirt...

...and piled it to one side.

We had plans for this pile of dirt, even as clay-y as it is.

For this year, we're concentrating on developing only about half the garden space.

The idea was to make four rows of beds. Once the ground was prepped, we ran string lines and spray-painted those lines onto the ground.

The big difference between this garden and our old garden is we're burying the drip pipes in the ground. The old garden kinda just grew organically, with very little planning. This time the garden is being meticulously planned, with underground plumbing and each bed having its own hose bib that comes up.

Therefore the next step was to dig trenches to bury the irrigation hose. Don used the subsoiler attachment on the tractor.

This useful gadget rips a neat trench. The depth of the trench is determined by how high or low the tractor's PTO is placed.

Following the spray-painted lines, Don ripped four trenches. Notice the heavy clay "bricks" that resulted.

After this, we had to hand-dig the trenches to clear them out.

Down the length of the trench, we laid 1-inch black plastic irrigation hose. At 11-foot intervals, Don put a T-connection to a bib that came up out of the trench. After this, we buried the hose. And can you believe I didn't take photos of these steps? Next go-around, you can be sure I will.

The result is a series of bibs that stick up out of the ground along one now-covered-up trench (center-left of this photo).

Here's what one of the bibs looks like. It's pinched off until we need it so insects don't crawl down the pipe.

Next step: Weed control! Several months ago, we purchased several rolls of industrial-strength weed cloth. Now it was time to use it.

We broke open one roll and laid it out.

Then we dragged it over the top of the hose bibs, and Don cut holes in the fabric to let the bibs poke out. The weed cloth is wide enough to cover two trenches, so we rolled up the excess so it wouldn't get damaged by any tractor activity.

Here's a hose bib, stick up out of the weed cloth.

Then it was time to lay down gravel to anchor the weed cloth and provide drainage for the garden beds. Earlier, we had a neighbor (who is a heavy-equipment operator) deliver us a load of gravel right next to the garden area. Don used the tractor to scoop up buckets of gravel...

...and dump it on the weed cloth. (Notice how the wheels don't crush the cloth because we rolled up the extra.)

It took a little practice to figure out how much to dump so it would spread out to an even layer.

While he continued dumping buckets of gravel at intervals down the line...

...I started spreading it out. It wasn't necessary to make it any thicker than "one rock" thick.

Once all the rock was spread out, we ran a string.

This allowed us to line up the beds nice and straight.

Then we brought up the first row of beds.

We made sure they were all snugged up against the string line...

...and spaced them three feet apart with the hose bib on the outside.

We left a gap between two of the boxes (a bit down the row) because we have a future project planned for that space.

Then we started preparing the soil to fill the beds. For this, we used a great deal of organic and inorganic material. We started by carting away all the accumulated sawdust Older Daughter had created in the woodshop so far.

Next, we ordered a dump truck load of compost from a local landscape business. (Once we get livestock, we'll be able to create our own bulk compost, but for now we had to purchase it.)

We also got a dump truck full of sand, but I forget to get a photo of it.

We also emptied the bin of leaves by the side of the house.

What the heck, we even tossed in a bucket of ashes from the wood cookstove.

We were left with multiple piles of material to mix up to fill the beds: Dirt, compost, sand, sawdust, and leaves.

(Although it doesn't look it from this angle, the piles of sawdust and leaves are actually quite small compared to the other piles. We're fully aware of the folly of putting too much undecomposed sawdust in garden beds.)

Don started scooping up buckets from the various piles in a 9:6:3:1 ratio: 9 buckets of dirt, 6 buckets of compost, 3 buckets of sand, and 1 bucket each of sawdust and leaves. (We would have used more leaves, but we didn't have that many.) He spread it out in a long line.

Then using the rototiller attachment on the tractor, he started churning it up.

The result was a beautiful, friable mixture.

Remember, that pile of dirt he scraped off the garden top is heavy clay. Mixing it with both organic (compost/sawdust/leaves) and inorganic (sand) material breaks it up and will allow the plants the ability to extract the nutrients without getting baked into hard clay. We've been down that path before and weren't about to repeat our early gardening mistakes from many years ago.

(Comical aside: We have some neighbors who moved in from the city about two years ago, eager to embrace a rural lifestyle. Since they had done some successful backyard gardening in their urban home, they felt confident about their skills here. They plowed a good-sized garden space, planted a generous garden, and were happy when things started growing so beautifully – until summer arrived and the ground hardened up. No matter how much they watered, their poor plants got baked into rock-hard clay soil. Now they know about the wonders of raised beds as a solution to this problem and can look forward to more success in the future.)

Before filling the beds, though, we were a little stymied by the gaps between the boxes and the uneven ground. Would soil push through? We didn't know, and started batting around ideas how best to block those gaps.

We tried pushing the rock aside to let the beds rest directly on the weed cloth, but that was just a pain in the patookus and we didn't like the results.

Then Don had a brainstorm: Why not line the inside edges of each box with leaves to block the gaps? By the time the leaves decompose, the soil should be packed enough not to spill out. So that's what we did. (I knew those leaves would come in handy.)

With that obstacle out of the way, Don started scooping up the mixed soil and dumping it into the boxes.

It took a few tries to figure out how many scoops were needed to fill a bed.

Some of the far boxes are filled, and we raked them flat.

That's where the garden stands currently. We have the first row of beds fully installed and ready to plant (I'll be planting strawberries and garlic in them later on). We have the irrigation hose buried for the second rod, with the hose bibs standing upright and ready to go.

Right now Don is hard at work, making lots more boxes. We hope to have 36 beds in place before winter, with plans to double that as time permits. Additionally, the garden area will be fenced larger than where the beds are, and we'll have a small garden shed (for tools) and un-boxed areas at either end for field crops such as corn and wheat.

It's just the beginning of what we hope will be a vastly satisfying project over the next couple of years.