Asaf, I find that learning when to harvest any variety of eggplant comes with a little experience, and watching the fruit for appearance. Once the fruit begins to grow, the skin will become glossy. Glossy, shiny fruit tastes best. As it matures and reaches full size, the skin will loose that glossy, shiny appearance, and will begin to dull. The dullness is a sign that the seeds are developing, and the taste will not usually be as good as those with a shiny skin. If left on the plant, it will begin to develop a yellowish, brownish color (color changes vary by variety.) The color change is a sign that the seeds are developing and the taste will become bitter. So, by keeping watch on the fruits as they grow, you'll notice that one day they will still be shiny/glossy, and the next day they will begin to become dull. I like to harvest while the fruit is still shiny, but it's just beginning to become dull. When you get experience with a certain variety, you will know when a fruit has reached it's optimum size, but the skin still has that shininess. Overall, as said in comments above, regardless of variety, it's not size that tells the grower when to pick. It's the shine. One fruit on a single plant could be 3", another could be 8". Eggplant has an average size depending on the seed and variety type, but fruit size is very variable... even on the same plant. I hope that helps.

I decided to leave them out. Just spend a few hours in a still hot sun to position them from the winds. It's just still too mild to wanna move them. At worst in the extended I see temps in the 60's and low in the 50's. And they get unobstructed southern sun all day long. When I move them, they go into a sunny, big garage, but it's hard to keep up with the watering..., bad enough in the winter. I was considering fertilizing for the last time of the season (they haven't been fertilized in over a month), but figured the excessive rains would just leach the fertilizer out. I spent time tilling the soil and introducing more gypsum. I don't use a gritty mix but they get so darn dry in more peat/perlite based soils. Spent time hosing them down well. Been a dry Fall so far so all the rain in appreciated. I do notice that plants seem to respond better to RAIN than water out of a hose. Didn't use to believe this but in my experience tropical plants grow better with regular rain that can't be made up from irrigation. Is it too late to consider fertilizing? (I don not fertilize at all in the winter as they are kept quite cold.)

5-6 years is a long time for me. Only thing I've had live that long has been hostas and peonies. The biggest problem is I have a really shady yard. I could put it in a pot, so long as I don't have to bring it indoors in winter, my house is so dark I can barely keep philodendron alive. I swear, my next house is going to have windows that actually let in LIGHT and treeless yard! Anyone know how big of a pot would it take? Other than potting it, I'm just not sure where I can plant it. I understand they only get a couple feet tall, but can be wider than that? How long does it take to get that big? I want everyone to know I feel like an idiot here. I was just thinking, "Oh it's an herb. Grow it just like you do any other herb." and I didn't even look into it. I'm normally not quite so much of a dunce gardener.

Tough call in this case. The plant is now large enough to have roots touching the pot surface inside. If the whole soil mass will move as one piece, you could add soil to the bottom, do not add soil to the top. If your in ground soil has warmed up, you can plant it there and lose maybe a week or two to transplant shock. Eggplant needs a very hot location to do its best.