Consider that the trellis has to be on the northside of the beds and how many plants you are planning on trellising. I could use 10 to 20 sqft just for pole beans. Tomatoes primed to a single main stem can be spaced at 1 per. Cherry toms need several plants to produce any quantity at a single time also. Also some of your seeds are cool season so those could be in and out before your warm season crops leaving more room.

Consider that the trellis has to be on the northside of the beds and how many plants you are planning on trellising. I could use 10 to 20 sqft just for pole beans. Tomatoes primed to a single main stem can be spaced at 1 per. Cherry toms need several plants to produce any quantity at a single time also. Also some of your seeds are cool season so those could be in and out before your warm season crops leaving more room.

I dont know-like the book mentions-I would start small for the first year to see if you like it. You can always add more during the season if you like it that much. I understand what Mindy is saying about putting trellis on north, but it doesnt have to be that way. For example, maybe you want to intentionally shade a part of your garden to grow things in the summer, like lettuce. As a general rule though, it is good to go on north side. I'd also follow instructions in book to a tee....

The trellis will definitely be on the north side. My only concern now is the size of the box i should construct given I had 5 different varieties of tomatoes as well as cucumber and pole bean seeds. How many plants of cucumbers and pole beans are too many? The book says 2 per square for cukes and 8 for pole beans. Would 1 square of each yield a lot?

With that being said, assuming I can get away with 1 square each for the tomatoes, cukes and pole beans, my length should be 7 ft (or 8ft to make things easier). How about width, given I have all those other plants.

Don't go more than 4 feet wide. You have to be able to reach to the middle of the bed without stepping into it. I found that my parsley got really huge, so I plan on growing it in a separate pot next season.

Here is a link that might be useful: What's Growing On?

I'm tall and I have long arms...for a girl at least and if I could change one thing I would have gone only 3 ft on width. 1 sqft of pole beans is def not enough!

Awesome replies everyone! I think I will make two 4'x3' boxes as opposed to one big 8x3 BUT I will keep them nudged up against each other (I can move them around and rotate them from season to season If need be). I'm trying to visualize reaching into the 3rd row from the front and it's a little uncomfortable and awkward - especially having lost the north side access due to the trellis.

I have been getting seeds started and studying what will companion with which. Then I thought of a space that I have that might make a good SFG. It's approx. 2 ft. wide and about 12 - 14 ft. long. I would like to get feed back on this plan. Remember the bed is two ft. wide.
2 ft. Tomatoes; 1 ft onions; 1 ft. lettuce; 1ft. carrots; 2 ft.tomatoes; 1 ft. onion; 2 ft. peppers. I would probably go another 2 ft. with squash, either summer or winter.
Ideas please. I'm in zone 8 Dallas, Ft. Worth, TX. area.