Pounds per square foot?

I had someone recently ask me "how many pounds of food can I grow in a 4'x4' garden?" An interesting question, the answer(s) to which obviously are obviously quite heavily determined by WHAT you grow (and growing zone).  But if one would have to make a guess for a typical garden (in New England) that grows some spring greens & peas, summer crops like tomatoes, peppers, eggplant etc., and some fall greens & such).  What would anyone guess that the average yield per square foot would be?….I'm thinking it's 7-8 perhaps?  Interested in your thoughts.

Hmm.... I've been keeping a tally of my harvest but have no firm numbers yet for this year,as the season continues. A few years ago I got just about 300# out of 300 sq. feet of garden.that wasn't a stellar harvest year either. I am hoping to surpass that yield this year.

Pounds per sf is very tough...might be easier to figure "Salads" per square foot. 

That sounds so very crop dependent. For instance, peppers don't weigh much, so even a great crop isn't going to be breaking any scales, whereas tomatoes can be so heavy that even a relatively poor crop could add up fast in comparison, weight-wise. And some tomatoes, peppers, etc., are heavier producers than others.

Then there's also the question of whether one intends to extend the season either early or late, or even have anything growing through the winter at all.

Maybe a better question might be one that asks how many pounds of a specific crop, or even a specific cultivar, can be grown per season. It would probably lead to a more useful answer, too. Telling someone you've been able to grow about X pounds of Roma tomatoes per square foot during the summer and X pounds of Sugar Snap peas per square foot during the fall and spring is a lot more tangible and easy to wrap the mind around than addressing the production of something as vague as "food."

I agree that the yield per square foot would be VERY crop dependent, and also would different for various climate regions.

Having said that, with the combination of vegetables I grow, my garden averages just under two pounds per square foot of garden space.   (Excluding the asparagus bed which is too new to produce anything yet). 

But please understand that every garden will be different.

Perhaps the best thing to do is to invite them to look at the "Showcase of Gardens" forum on this site.

I've kept records over the past 5 years.  Melons have yielded up to 7 pounds per square foot if grown vertically, cherry tomatoes 5 pounds per square foot, strawberries 1 pound, peas 0.5 pounds, and lettuce less than 0.5 pounds per SF, etc..   Some squares yield nothing due to diseases and bugs.    

When I average the entire garden,  my overall yields have ranged from 0.4 pounds to 1.0 pounds per square foot.   That is for a wide variety of vegetables and fruits in Maryland, including spring, summer, and fall harvests.  No greenhouse.

Mike