Most of the seed potatoes that are sold in nurseries in Ontario, Canada (where I'm guessing the OP lives, since the OP posts on the Toronto/ON board) are typical russets/reds/yukon gold/kennebec/superior potatoes, not the low GI kind. They don't list the Glycemic Index on the packages for seed potatoes.
You can grow potatoes from the type that you buy at the store, if the type at the store are not genetically modified hybrids that have the capability to reproduce bred out of them. If you leave the potatoes you like in a cool, dark place for a month or so, they should grow eyes. Once the eyes have developed, cut the potato into a few pieces, with at least 1 eye on piece, and plant the pieces about 8 inches deep in well-worked soil, about a 18 inches between plants.
I've grown fingerlings from the fingerlings I've bought in the basement of the St Lawrence Market vendors in Toronto.
It's generally a good idea to start with seed potatoes, from a nursery, because some are blight resistant and might have other good attributes, but if you want to grow your own from what you buy at the store, give it a try.
By the way, itryalot, I realize you were eager to start your garden on the TO board. Here in southern Ontario, I usually plant my potatoes Victoria Day weekend, or the first weekend in June.
i'm not familiar with the glycemic index of different potato varieties, but I don't see why you wouldn't be able to use a type of potato you like from the supermarket. Make sure it's organic because the industrially grown potatoes are treated to prevent sprouting. I've had good luck growing potatoes from "seed" potatoes from Irish Eyes Seeds (http://www.irisheyesgardenseeds.com/). I've grown the Yellow Finn variety (similar to Yukon Gold but smaller in size) and the Bintje variety (also similar to Yukon Gold but a creamier texture and robust potato flavor). Bintje is the most common grown outside of the U.S. from what I understand, and for good reason. Easy to grow as well - I use a potato grow bag purchased from a garden suppy catalog.
Make sure to let your seed potatoes sprout before planting - leave them in a sunny spot for about 10 days and when the sprouts are 1-2 inches long they're ready to plant.
Here's a link to a university study; seems precooking and reheating can lower the GI of some varieties.
I have grown some fabulous All Blues-- purple skin, white mealy flesh and good earthy potato flavor. I get them as a 'potato assortment' in mesh bags from Trader Joe's, cut them into chunks, let dry for a couple of days, then plant them. They had no trouble sprouting.
Mulch any potato crop deeply (8-12") to prevent skin greening, which is poisonous. Store away from light to prevent sprouting.
I can't say whether one variety has a higher or lower gI than another, but a great resource for all things potato is Peaceful Valley Garden Supply (groworganic.com). Usually planting grocery store spuds isn't recommended, but if you must, organic ones are the way to go.
Ah! Is that common parlance now?
Just made, and looked up plantain;
The GI for a raw plantain is 68 (on a 100-point scale).
Ripe Plantain, Boiled
A ripe plantain that has been boiled for 10 minutes has a GI of 66.
Green Plantain, Boiled
A green plantain that has been boiled for 10 minutes has a GI of 39.
Ripe Plantain, Fried
A ripe plantain that has been fried in vegetable oil has a GI of 90.
Green Plantain, Fried
A green plantain that has been fried in vegetable oil has a GI of 40
Read more: What Is Glycemic Index of Plantains? | eHow.com http://www.ehow.com/facts_5765402_gly...
Interesting difference between green and ripe. Is that right? Who calls the line between green and ripe? Green boiled and green fried the same? That would be awesome!
Sorry. Off topic.
Don't know what low GI means.
A lot of potatoes at the store have been treated to prevent sprouting. I've had both excellent and dismal results from planting them. I assume that if your store has organic potatoes they might not have been treated.
If you have a good "feed and seed" store in your community I would advise buying some seed potatoes from them this spring. For whatever reasons the online company's prices seem extremely high to me for potatoes.