Well, it depends. I think rutabaga is milder and sweeter, but it does have a very distinctive taste. To me, turnip is more bitter. Unless you get very small turnips, then they can be milder and sweeter. I think you should get some of both and try them. I love rutabaga, and I also like turnips, but rutabaga is my favorite. Because taste is subjective, not objective, I'm sure others will disagree, which is why I think you should taste both yourself.

The only one that is an appropriate substitute for a potato, in my opinion, is rutabaga. It's somewhat starchy and has often been used where potatoes weren't available. Turnips are wetter and more pungent, in a raddishy kind of way. I've successfully used turnips for flavor as a replacement for onions.

I prefer rutabaga....I mash with butter and nutmeg. Yum!

Rutabaga preference here, as well. Love it mashed with some apples, a little brown sugar and butter!

I told DH to buy either rutabaga or small turnips. The store doesn't always have rutabaga.
We'll be making this in a few days. I'll let you know how it turns out.

The online carb counter I checked had the following values for 1 cup of cubes, potatoes - 13g, rutabagas - 11g, and turnips - 4g. I have no idea the accuracy of the website I found. For a whole pot of soup, there would seem to be little difference between using potatoes and rutabagas.

btw, I LOVE both rutabagas and turnips.

Interesting. I've no idea what site I used, but I'm pretty sure that there was a greater difference in carbs. Perhaps it was net carbs, i.e subtracting the 5 grams of fiber. I also checked parsnips. They were much higher than potatoes.

It will be 4 or 5 days before we make it, but I'll let you know.

I made turnip "fries," roasted in the oven. Really tasty, but I felt like I wasted so much of the turnip---after I cut away that woody center core, there was hardly any turnip left to roast. Is this typical? Clearly, I don't have a lot of turnip experience! :)

Book, did the recipe call for coring the turnips? I've never cored turnips, but I've never roasted them either.

I've never cored a turnip. One of my favorite things to do with turnips is make "turnip chips". Get a big flat turnip--disk shaped rather than pointy (there always seems to be at least one in the bin). Just wash and trim the ends, then use a mandoline on its finest setting to make really thin chips. They should look something like flat Pringle's. I use the .5mm setting. Spread them out on an enamel or non-stick baking sheet, or parchment if you don't have one. They can be touching, should be close together, but not overlapping. Use a ribbon grater like Microplane to cover the whole thing with wisps of a sharp, hard cheese. I like New York aged white cheddar, but you could use anything with a lot of flavor. It doesn't take a lot of cheese because the ribbons are so wispy, and the flavor of the cheese is enough that you don't need more. Broil at 375, or whatever works for your oven, until starting to brown and the turnips look a bit dryer. Serve warm. They may all go before you have a chance to put them on a serving plate. The results are soft, but way yummy. I even had one cooled once and it was good. They're best piping hot, and as I said, most don't linger to the point where you can test at other temps.

I didn't really follow a particular recipe. I got the idea from Ina Garten's roasted root vegetable soup, so was roasting carrots and turnips. The turnips looked like white carrots on steroids, and I chose what were the smaller ones in the bin. All of them had a woody core down the center and it seemed like everywhere I looked on line called for removing that core. Plllog, when you say you've never cored a turnip, did your turnips have cores? (what a funny question to ask!) Mine were pretty big, maybe it is a function of size.

Bookmom, the turnips I use look like this, not like carrots.

From reading plllog's description, it sounds like the ones she's using are similar to the picture.

What Bbstx posted is a picture of turnips. The "white carrots on steroids" are parsnips. Entirely different vegetables. Turnips, as you can see in the picture, range from Christmas ball shaped (the two in the back) to the iconic round but pointy toward the root end shape (like the one on the right but often fatter--that's a small one), and flatter, disc shaped (the big one is actually pretty pointy, but if you imagine that the white side is shaped like the purple side, with a root nubbin in the middle, you'll get the picture. That's the kind I use for chips.) There might be a few varieties of turnips that look different, but your basic grocery store turnip will always have a purple top like in the picture.

Parsnips are a light beige to white color and shaped pretty much like carrots, but fatter at the tops. They also are sometimes sold in gigantor sizes, while other times they're the size of an average carrot. They're also pungent, but sweeter than turnips, and harder/less watery.

Rutabagas (also known as Swedes) look a lot like dirty turnips, but have a very different composition and flavor. The flesh is a golden yellow, almost sweet potato color, and while they're also round topped and pointy bottomed, the point tends to be fatter and more carroty in shape than the turnip's nubbin. For your basic grocery store type, the top is also purple but it's darker and less vibrant than a turnip's. Rutabagas also have a lot of little hairy roots along the sides, whereas turnips are pretty smooth. Rutabagas taste sweet and are sometimes subbed for sweet potatoes. They're also used as a replacement for white potatoes in many dishes, but I think that's more about availability or flavor (they definitely have more flavor than potatoes, though they're mild and not nearly as pungent as turnips), not about cutting carbs.

All turnips have a core. I've never had the core of even a giant turnip be distinctively woodier, to the point of wanting to cut it away. That's why I posted about the turnip chips. It uses the whole turnip. There's hardly anything left if you remove the core. It's mostly core with a very thin rind of softer flesh.

There would be more left of a parsnip if you removed the core. It's more like a carrot inside, with a distinct, round core. I only buy the gigantor ones for making stock and throw them in in whole large chunks, but then only if there aren't any smaller ones. I'll use the medium sized ones for general cooking, however; the ones that are bigger than a horse carrot but not weapon sized. I don't remove the core from them, either. That's for things like pot pie or tsimmis (sort of vegetable stew), where everything gets cooked ahead to the same point of doneness and then cooked more once assembled. That might be the optimal size for something like fries if you want to remove the core because there's about an equal amount of core and outside. Or you could wait until you find small, carrot sized ones and use them whole.

Parsnips are flavorful and a bit sweet, though not very starchy. Twice the sugar of a turnip, with about the same amount of total carbs. Not really a substitute for a potato, but good nonetheless. Go ahead and put them in your soup.

Oh man, I am embarrassed! Pllog is right, I was using parsnips, not turnips. (hiding face in shame..) Oh well, thank you all for the help for this clueless cook. Those parsnip fries were pretty good, but like I said, once I cut the core out, there wasn't much left to roast. I did eat some roasted, and put the rest in the Ina-inspired soup. Next time, I'll try turnips.

Thanks again, ladies, for your explanation and your patience.

How to core a parsnip...

Bookmom, no need to be embarrassed! Whether it was because you weren't very familiar with these roots or just had one of those slip moments when you say the wrong word, it happens to everyone. Sometimes, a picture or a thorough explanation help communication a lot! But really that's all it was. We were trying to communicate with you, not shame you. How did the soup come out?

Annie, thanks for the video clip. That's actually how I cored them, it was pretty intuitive.

The soup was OK, but I can't blame Ina for the meh results since I tinkered with her recipe a great deal. And those parsnip fries turned out to be so yummy that I ate most of them before they hit the soup pot.

plllog, no worries--I did not think anyone responding here was trying to make me feel badly about my error--I just really appreciate the helpful responses in spite of my ditzy mistake. :)
Apparently, it's true. A picture is worth a thousand words.