There are too many variables to get a meaningful answer to that question. Two big ones would be, what are you trying to grow and harvest and the biggest variable is the work ethics of the person doing the tending.

John

Here is a link that might be useful: Johns Journal

Work ethic: what ever you consider the average full-time ca$h Square Foot Gardeners work ethic to be.

Again, there will be no bending or kneeling which I would think should eliminate a lot of fatigue.

Trying to grow and harvest equal square feet of:

Swiss Chard, Radishes, Snap Beans, Peppers (both bell and hot), Cucumbers, & Lettuce.

If possible, please give your maximum estimate with and without a properly-functioning irrigation system.

Thank you!

pulpo

No one can give you the answer to this question. It is like asking how long is a piece of string.

What you grow, where you grow, how you water and mulch as well as your personal work ethic are huge variables.

My 70 year old neighbour can(and does) work me under the table when he helps me. I can out work lots of people 1/2 my age. It just depends!!!!

If you do it, be sure to post pictures and your results...

This post is an idea of someone doing cash from a Sq Ft Garden..

Here is a link that might be useful: Cash from a Sq Ft Garden

How many acres of land will you be putting these 4x4s on? I'm a (nearly) 70 year old woman of average build and I have the equivalent of probably 15 4x4s, which I tend maybe 15 minutes a day after all seeding/planting is done. Some days I don't "tend" at all. I doubt I had to pull more than 12 weeds this entire growing season, so once my beds were built it was a matter of planting, watering (mine is automatic, no work on my part) and harvesting. A bit longer in the fall to clean up the beds and amend the soil. I spend a lot more time looking at my garden and photographing it than I do "tending".

Granny

Here is a link that might be useful: Annie's Kitchen Garden

Mike and all -

If it makes it easier, please assume what you personally believe to be averages when assessing any variables that prevent you from providing an answer to this difficult question.

Or, for simplicity, please assume I am growing nothing but radishes and am capable of properly watering them via hand or via an adequate irrigation system.

Granny -

Thank you for sharing that useful information.

I plan on beginning by putting 30 4'x 8' elevated SFG boxes on top of a flat 46' x 41' area. The north/south isles would be 3' wide and the east/west isles would only be 1' wide - allowing for the possible setup of an elevated drip irrigation system running from the north to south.

Mel's first book (p. 32) makes it seem like the equivalent of 60 4'x4' SFG boxes would require maintenance of 30 minutes per box per week. If this is true, then 80 boxes would seem to be the most one could handle if they were tending 40 hours a week. I assume he is using an "average gardener" when calculating these figures.

If this is successful, I could probably do four more similarly sized layouts on my .5 arce lot.

Mike and all -

If it makes it easier, please assume what you personally believe to be averages when assessing any variables that prevent you from providing an answer to this difficult question.

Or, for simplicity, please assume I am growing nothing but radishes and am capable of properly watering them via hand or via an adequate irrigation system.

Granny -

Thank you for sharing that useful information.

I plan on beginning by putting 30 4'x 8' elevated SFG boxes on top of a flat 46' x 41' area. The north/south isles would be 3' wide and the east/west isles would only be 1' wide - allowing for the possible setup of an elevated drip irrigation system running from the north to south.

Mel's first book (p. 32) makes it seem like the equivalent of 60 4'x4' SFG boxes would require maintenance of 30 minutes per box per week. If this is true, then 80 boxes would seem to be the most one could handle if they were tending 40 hours a week. I assume he is using an "average gardener" when calculating these figures.

If this is successful, I could probably do four more similarly sized layouts on my .5 arce lot.

I want to be complete in my thoughts on this, because I'm considering something similar because of the economic climate, only I'm thinking more along the lines of helping needy neighbors. Please don't think of this as a negative post, more of an attempt to help you (and me)consider all the things involved here.
I don't know...other things to consider are:
1. What will be the cost of raising that many beds to waist level?
2. To do SFG exactly to the book, there is an initial layout cost. That cost can be mitigated by a variety of things: do you have manure or compost handy? Do you have a vermiculite source nearby? Do you have peat moss hanging about or coir? What about building wood? Do you have a free source near you? Do you have the tools to create these boxes?
3. What about local ordinances regarding in home businesses?
4. I agree with Granny, my weeding has been minimal. If you raise beds to waist high, you are going to have to weed your beds, and under your beds, unless you cover your lot with pea gravel, and even then, you'll have to deal with moss and weeds occasionally. IMHO, you'd have less work just leaving them on the ground unless you're unable to bend and move about.
5. The irrigation system would be worth any time/money it costs you. Again, just my opinion. I used to work with a lady who had a three acre row garden she watered with pails of water warmed in the sun, yada yada yada. I would want that effort, I'm lazy.
All of these things considered? I think with a half acre lot, you wouldn't be able to put in enough boxes to break a sweat normally. I have a third of an acre, and my lawn is by FAR more trouble than my garden, I know several folks who have multiple acre sfg's who work full time and garden part time. It does take an initial effort, but even that can be minimized with a couple of friends or neighbors helping out. The bigger amount of your time, and what you should be thinking about is going to be shop front stuff. Taxes, grocery bags, dealing with govt paperwork, dealing with crazy bureaucrats, etc... Sorry to be so chatty, but it helps me think though what I'm considering, too, lol.

First off, let me apologize for putting my unwanted opinion in. You are asking questions about commercialization to a bunch of home gardeners. I cannot speak for anybody else, but you may get better information from somebody who is in the SFG commercial business or contemplating it.

John

Here is a link that might be useful: Johns Journal

I am all too happy to answer your questions but it isn't quite on the topic of how many 4'x4' SFG boxes the average gardener could tend growing the average mix of crops (or simply growing turnips).

1. The cost can range from about $130 in materials for a 4'x4' cedar tabletop SFG box that is about 32" above ground at soil level to about $215 for a custom box made of a steel frame (legs and support), ABS plastic sheeting as the bottom, and ipe hardwood as the siding.

2. Yes, there is an initial cost that I am prepared to invest. This includes paying a local metal artisan to build them for $215 per 4'x4' and me paying another $38.61 to fill each one up with the perfectly followed Mel's Mix recipe. Not including seeds, that brings my total investment per 4'x4' to $253.61.

3. My garden is not considered a home business as long as I do not sell out of my home. Taking my produce away from my home to sell elsewhere is perfectly fine according to my local government.

4. Weeds in the boxes will be tended to at waist level - which I believe to be far superior to bending. Weeds will not be an issue underneath my elevated beds. I will have shade-loving monkey grass there which should be too thick for weeds to compete with. My second choice would be Dutch White Clover and my third choice may be pea gravel. All of my isles will have a thick layer of wood chips.

5. With my sunny half acre lot, I have room for approximately 300 4'x4' elevated SFG boxes. Using data from Mel's Ca$H SFG book, I theoretically would receive a return of about $350 per 4'x4' by selling organic wholesale at current 2008 prices. Selling wholesale to organic local markets alleviates most of the retail regulations you mentioned. If I ever did get to the point where I was able to sell directly to restaurants - as Mel recommends in the book - then my potential profit is closer to $700 per 4'x4'; again that is assuming Mel's Typical Ca$h SFG Yield projections are accurate. And least I forget, all of his projections are based on a 6 month growing season.

So, now you can see that I am willing to invest a crazy amount of money while counting on projections that may be a fantasy. It still brings me to this question:

Can one able bodied man with average work ethic tend to the equivalent of 300 waist-high SFG boxes that are drip irrigated and only grow radishes?

Thank you all!

pulpo

Pulpo - I would like to share my thoughts with you, concerning gardening work ethics. There are all types of gardeners out there, and each one has a different work ethic about them. Please keep in mind that i'm attempting to give you useful information, and not belittle anyone for their efforts.... I respect all gardeners, including you. You have :
1. Some that plant a few seeds, and just expect something to grow, with basically minimal input. Believe it or not - sometimes they have remarkable output. Others work their butt off performing the various necessary chores, and fail miserably.
2. Some that live in a location where all of the favorable criteria is present for pest infestations, short growing periods, successes and failures based on all kinds of parameters.
3. Some that plant gardens whole-heartedly, when in reality - they really don't have the time available in their daily schedule to take on such a chore as this.

Like the others said, there are all kinds of parameters involved. Everyone of us has a different success/failure story, and it changes every year.

We can only tell you about our individual gardening experiences, and what is involved.

I have 136 sqft to garden, and work 50 hours per week at my regular job. The personal demands that I place upon my gardening success is beyond the average gardener, because for me - failure is never an option. In the summertime, I tend to it at least 4 hours each day - solely for handpicking various pests, and watering everything. Because of this, my garden is probably 80 - 90% successful. It should be better next year, because of all of the knowledge that I gained this year - with this new method, as well as different vegetables grown. But, it could also average worse, because just as sure as I get one of my problems from this previous year solved, another,different problem will show up next year.
I will say this much....you did yourself a favor by choosing some of the more easier vegetables to grow and maintain. Cucumbers will require hand picking of cucumber beetles, lettuce and swiss chard should be a breeze with a weekly application of BT. I really can't comment on the other veggies......Just don't fill all of the boxes with squash plants.....you'll end up with a squashbug infestation that will likely make you turn the entire garden into a towering inferno - then calmly go to the nearest bar to drink your sorrows away. Personally, I feel that.....
If I didn't have my regular job to go to each day, I feel that I could easily keep 960 square feet maintained as well as my current garden, but then again - my motivation and drive is probably 5 times that of a normal person. That's why I get so many things built.
Maybe this is of some help to you.....If not, i'm certainly sorry. You asked a very complex question, and we are only trying to give you information.

EG

All answers are appreciated, EG & John. Thank you both for taking the time to reply.