When you say best yields, how do you mean it? In terms of pounds per plant or overall yield?

Here's my favorites for overall yield compared to square foot of space devoted to the plants:

Tomatoes
Peppers, Hot and Sweet
Sweet Corn
Onions
Irish Potatoes
Pole Beans
Summer Squash
Okra
Carrots (yield a lot per square foot, relatively speaking, because you can plant a lot of them per square foot)
Southern Peas

If you want the names of specific varieties of each of those that yield well, here's a few, and I've tried to list some easier-to-find hybrids though I plant lots of the more obscure heirlooms myself:

Tomatoes:
Slicers--Fourth of July, Goliath, Jetstar, Indian Stripe, Dr. Wyche's Yellow, Brandy Boy (pink), Big Beef, Big Boy, Better Boy
Paste--San Marzano Redorta, Heidi, Rutgers, Viva Italia
Cherry--SunGold (golden orange), Sweet Million (red), Ildi (yellow), Black Cherry (black), Tess's Land Race Currant (red, and one of these is all you need)
For sun-dried tomatoes: Principe' Borghese
For containers: Bush Goliath, Sweet Baby Girl, Husky Red Cherry, Jaune Flammee
Peppers:
Jalapeno--Mucho Nacho,
Habanero--Chichen Itza
Sweet Non-Bell--Yummy Orange
Sweet Bells: Blushing Beauty and Roumanian Rainbow both are the heaviest yielders I've ever grown but any of the 'Beauty' series like 'Purple Beauty', 'Chocolate Beauty', 'Orange Beauty', etc. produce well
Sweet Corn: for early corn and also a space-saving smallish variety "Early SunGlow", for mid-season "Sugar Bun", for later season "Country Gentleman" (shoepeg type), "Silver Queen" or "Texas Honey June" (tightly-wrapped corn husks that help exclude earworms)
Onions:
bulbing--Texas Supersweet (1015Y), Candy, Red Grano
for green onions--Evergreen Bunching
Irish Potatoes: Red LaSoda or Red Pontiac, Kennebec, Yukon Gold
Pole Beans, Snap: Rattlesnake, Garrafal Oro/Smeraldo, Kentucky Wonder, Trionfo Violetto, Lazy Housewife
If bush beans are preferred since they do not have to be trellised: Contender, Speedy, Provider, Derby
Summer Squash:
Yellow: Yellow Straightneck and Horn of Plenty
Green zucchini types: Raven, Cocozelle
Pattypan types: Sunburst
Middle Eastern light green type: Magda
Okra: Stewart's Zeebest easily outyields any other variety I've ever grown by at least 5 to 1 but needs wide spacing to be that productive. If space is an issue, Lee, or for earlier yields, Annie Oakley II
Carrots: Napoli, Yaya, Tendersweet, Paris Market (small, round carrots great for difficult soils or containers, Purple Haze, Atomic Red.
Southern Peas: Purple Hull Pink Eye, Knuckle, Colossus

I could go on and on forever.

For a really compact watermelon that produces great yields for a watermelon: Bush Sugar Baby, Sugar Baby, Blacktail Mountain.

In the herb world, chives, basils and mints (in containers, or it will take over the entire county) produce really great yields in a small space.

If space is not a problem, sweet potatoes produce bountifully. It takes 3 50 ft rows of Irish Potatoes for us to dig 200 lbs around 4th of July, but only one 50 ft row of sweet potatoes gives that much in October. Of course, we dig into the Irish potatoes and eat new potatoes for a month before we dig the main crop, but even taking that into account the sweets are more productive.

Thank you, Dawn. As usual you've gone above and beyond. I really just want people to be successful in their first year of gardening, then they're sucked in ; ). I usually suggest they start smaller so they can keep up with it and not get overwhelmed,

I've had people say, "oh I just grow whatever the big box store has - I'm sure that's what grow here". While it may grow.. It's not always the best producer, in that, you get very little vegetable from it.

And thank you mulberryknob, she has moved in with her dad to go to college and he has acerage, I think this year she's starting small - but maybe she could do a row or two ... (do gardeners know what small is-LOL)

Melissia, You're welcome. I don't buy many seed varieties off the seed rack because they usually are not varieties that necessarily do well here. I agree with you that they grow but do not necessarily produce well. The buyers for national chains choose varieties adapted over a wide area, but our gardening climate is more difficult than most and using the right varieties makes a huge difference.

I hope your friend has a successful first year of gardening.

Dawn

Don't forget greens! Lettuce (cut & come again), spinach, chard, etc are all terribly easy to grow and you can get a lot of confidence-building bulk from them.

Diane

Diane, If she wants more bang for the bulk maybe you can show her a picture of your Tess's Land Race tomato. You know which one. I think it ate the neighbors kids or something. LOL

I've linked one below. Here's another from about a month earlier: http://speedkin.com/2010/06/22/feed-me-seymour/

I'm growing more Tess this year. I can't wait to freak out the neighbors! I'm also growing sword beans that get HUGE just to further freak out the neighbors. Gotta give 'em something new to talk about each year, right?

Diane

Here is a link that might be useful: Tess' Landrace tomato

Omgosh!!! Now I WANT that tomato --- I'll have to get some seeds and share with her.

I think every gardener should be required to grow Tess at least once. Tiny tomatoes but great flavor and bazillions of them!

Diane

By the way, there's a standard sized CRW cage in that plant but you can't even tell. HUGE plant.

Diane

Melissa, It is a currant so the tomatoes are tiny, but you will get tired of picking them. I usually grow lots of small tomatoes and I share with friends. One of my friends will go through the bowl I take to her and pick out all of the Tess. She is one of those people that if you ask what kind of tomato she likes, she will say "red". I thought it was funny to see her picking out all of those tiny tomatoes to use first. She loves them.

One year I had one growing on a big arched trellis in my garden. I stood up and picked until I got tired, so I flipped my garden kneeler over and sat down to pick the rest. My DH came into the yard and had been working out there for a long time before I spoke to him. He jumped. The plant was so thick that he didn't know I was in the garden with him.

Diane, Those photos of TLRC with the kids are my all-time favorite tomato plant photos.

The nice thing about Tess is that if you get tired of picking them, you can just leave them alone and the fruit will fall to the ground and you'll have a million more TLRC plants next year.

My biggeset Tess's Land Race Currant ever was in an 8' tall cage. When I refused to add another cage to the top, the plant began "weeping" back down towards the ground, ultimately reaching a length of 16'. I cut it off when it reached the ground because I didn't want it spreading out sideways and taking over every square foot of the garden. It was beside a pathway and I had to hack away at one side constantly to keep the pathway open. I think that was in 2010, but it could have been 2009. That's the only year I've ever had to climb a ladder to pick tomatoes, and it wasn't easy to do that either because my garden slopes downhill.

Melissia, You can spend hours picking these little tomatoes, but they are so tasty it is worth it. Tess's Land Race Currant was from a breeding project at Even Star farms and I am glad they spent the time breeding and selecting it.

Dawn

I actually like the taste of smaller tomatoes better than most of the big ones.

I don't think I can/should put this in my "actual" garden -- it would take over. However, I'm going to put it out somewhere : )

I haven't got near the planting done I wanted to this week - I've been making soap with friends and today I have to go to Arkansas and pick up a welder for DH... so doesn't look like I'll get much in before my rain like I wanted to.

Along the line of rampant production, I would recommend Old Timey Cornfield Pumpkin (c. moschata). Last year was nearly a complete wash for our garden production. It took me three tries to get winter squash to grow. So it started quite late. Production was down from normal. Yet, we still have at least 50 lb of winter squash to process from last fall's harvest.

The first year I grew it, six plants of Old Timey Cornfield Pumpkin filled about 20'X 30'and produced over 400 lb of usable fruit.

It's not a space saver. But if one wants a low maintenance crop which really produces, this is a good one. I haven't grown Seminole. But my suspicion is that it produces about the same.

George
Tahlequah, OK

Here is a link that might be useful: Old Timey Cornfield Pumpkin

George, how would you describe the flavor of the pumpkin? Is it similar to butternut? I plan to make room in the garden to plant some of the seeds you sent me, and I'm just curious. My husband is a bit of a picky eater. He likes butternut and the yellow straightneck summer squash and zuchini, but he doesn't care for acorn or spaghetti types. I'll eat it regardless, but if it's similar to the butternut I'll plant more of it since it's so prolific of a producer.

It is similar to butternut. When cooked and scraped out of the shell it looks like it has strings. But when eaten, they are not to be felt in the mouth. Most butternut don't even appear to have strings. Nevertheless, I would say this one is closer to butternut in flavor.

George