Oh, cool. I did not know that. Thanks! But would this apply to Thai basil as well? My parents just bought two huge Thai basil plants and they're pretty tall and leafy. I just picked off some flowers from it.

Thai basil is notorious for flowering despite best efforts to keep trimmed back. But it's so pretty as an ornamental too.

Yes--the process is the same for all basils. As soon as they get root bound or stressed, they want to flower. Cutting them back and either using the leaves, or rooting them for more plants is good for them. It depends on the size of the plant how far back, pics could help if you want an opinion. It's not really harvesting, but called pinching. Basic rule is a third at a time, but if it's healthy, I sometimes do more with my basils.

This is one of the two huge (first time seeing a Thai basil, sorry) Thai basils that my parents bought. It's like 2 to 3 1/2 feet tall, I think. Should I "pinch" them down to the last joint? The stems are kind of woody, though. Also, in the Philippines, where I'm from, vendors sell plants by two's or three's in one plastic container, and this Thai basil has 3. It was pretty rootbound, I was kind of afraid that I was going to kill it from trying to resolve the rootbound condition.

You are correct that those three will be so root bound so as not no longer separate without damage. I generally only do pairs in pots, and be mindful that they need more water then. If you want to thin them, I would just cut one whole stem at soil level. Philippines! I am assuming hot and humid--basil should thrive well.

For pinching back, when it is that woody, you do want to be more careful as the woody stems don't grow as much as the herbaceous ones. I think my strategy for this one would be to take about a quarter to third off the top of all, then kind of step down further in stages per branch, making sure that you have the new stems sprouting before switching branches so as to not add too much stress at a time. In about the center of your pic--that's what you're looking for when trying to pinch and make bush--a center stem with the leaf pair and at that juncture you get a secondary pair of stems that grow above the leaves.

I just found out that the other Thai basil (still in its plastic container) contains 4 mature Thai basil. I'm surprised it has not died yet. But anyway, I'll do as you said to all of my Thai basil. Thank you!

Yeah, I hope my basil would thrive here. It will get rainy and there will be typhoons coming the next few months... I'm hoping to get all the leaves I can before typhoons come in so I can have some mighty pesto and whatnot. :))