Good Morning.
I'm not sure if anyone has answered your potato question. I'm trying to decide what you have. Since you indicated that there are 3 colors of your potato, I think you have an ornamental vine. It grows well in soil. There are typically 3 colors of leaves - bright light green, dark black/purple, and then a tri-colored leaf. If this is what you have, it is grown specifically for ornamental use. It really doesn't produce edible potatoes. You can check out any seed catalog online - such as
www.whiteflowerfarm.com.
As far as growing edible potatoes is concerned....the potatoes that you purchase in the store don't grow very well. They have chemicals on them for growth retardation. You should go to your local plant nursery and ask about their varieties they have for sale. Potatoes grow best in cool weather. I don't know how well they will do in FL. For you, they probably should have been planted in Nov or Dec. Here we plant them in March. If you do raise potatoes, checking to see if you have new potatoes is the best part. It is thrilling to find your first new potato. First of all, the ground around your potato plant should be very loose to allow the roots to spread out, on which the potatoes are formed. When checking for new potatoes, you will gently just lift up one side of the plant - preferably away from the plant. You really don't bother the main plant. You are just moving dirt away to see if you can spot any new potatoes. As the potato plant grows, most gardeners add mulch on top, such as straw, to keep the soil loose. We plant in March for May or June harvest of small potatoes.
I hope this helps,
Carolyn