Cross pollination only affects seed; the original plants will not change. Since we usually eat the leaves of basil, it will have no effect from cross pollination. However, basil is so pungent that there might be some flavor exchange if you serve them together.

hi Paul.. the above comment can be very true, however, if your living in a city and have no outdoor space, like me, then we grow on our window sill :) Actually what I do is place my basil on a small table just near a window. My Basil is from seeds planted in May and they are still growing in their small terra cotta pots.. just be sure that your pot drains well. And at least once a week(on the really nice days) I open the windows or take it out to my sun porch where my other herbs currently are. To help with your infestation, you may want to think about purchasing an insect killer spray. Or if you prefer organic you can always google how to make your own..there's a ton of websites that can give you instructions.. or stick with your current method if it seems to be working. Imho, I think you should re pot it in different soil. If you cannot get your finger an inch or so in then the soil may be too dense. You can buy just a little bag of good draining potting soil, or maybe you can ammend the soil you currently have with some sand and/or sphagnum moss. And go ahead and pinch those yellow leaves off. I wouldn't fertilize especially with it so late in the season. And make sure to freeze or dry some of your leaves before you've squeezed all the life of your plant that you can lol.. but I like to do this so that I can still enjoy the herb even in the cold cold months. But as I read over my advice I'm reminded that it is almost October so don't go and spend too much money and/or time as my indoor basil usually is a goner by the end of November. Good luck and remember "Nothing ventured, nothing gained!"

I grow basil too but it doesn't look like the supermarket monsters. Mine always has a much more bushy appearance - I guess real sun, real wind, and real rain do that. While I don't know for sure, I suspect the supermarket basil is primarily hydroponically grown. Have other vegetables grown in exactly the same place the basil is now? Successfully from seed? I've had similar problems with one of my garden beds that I have yet to do much with. The beds were here when we bought the house and much of the soil was badly spent. Seeds are nearly impossible to start in that bed and the seeds that do sprout are sad little things. Of course basil has had a problem with disease over the last number of years. Go to google and I'm sure you can find more information on Fusarium Wilt. See if any of those symptoms match your basil. FataMorgana

Another angle