My guess is, from present experience, that they survive fine in small containers until almost fully grown, so the garden centers are hoping they sell quickly at that age.

A friend sent me two dried flowering tops from her crop of cinnamon basil last Christmas. I wasn't sure what to do with them, so simply rubbed them together over a container of potting soil, then softly raked them deeper into the soil.

Well the potting soil was leftover from the year before, so, along with the basil came weeds. Problem is, the two of them look the same, almost, (I'm sure good gardeners could tell the differents, anyway LOL) until they bloom.

I thought I divided the weeds from the basil, and added all the extras into little 2" square containers, planning on putting them out front for anyone who wants them. Well, almost all are grown now, but some ended up starting to bloom seeds (weeds), so I don't want to give folks unknown weeds to eat.

Been a few weeks since then. Haven't had the guts to put the real ones out front, since they haven't developed their flower head yet. Three have dried up for unknown reasons, but the rest are fine.

Doesn't really answer your question, other to say that apparently they can hang out in really small containers for quite a while. (blushing)

The overgrown plants you see at nurseries are grown under near perfect conditions. That is they have fertilizer added, along with the correct amount or heat and light. In some cases these 'forced' plants can suddenly die due to unknown problems. Its usually when you buy them and they are gone to plant heaven in a week or two. Lots of times plants can be grown under soilless conditions (hydroponics) and then they pot them once they want to sell them. Root trimming may also be done to get them to fit in small pots.

When ready to sell plants, nurseries will give high-nitrogen fertiliser to them a week or so before putting them on sale so that the leaves will look wonderful. Most people buying them don't bother removing the plants from the pots to check out the root system. You really should, every time - those plants will almost always be potbound and will remain permanently stunted, though they will grow a bit more when potted on or planted in the garden. Plants in pots are always stunted to some degree. A large plant in a small pot is something I avoid like the plague. It will rarely be a truly healthy plant.

Honestly, a basil plant should be at least a metre tall and at least as wide as that, too. Usually more, both ways. And the roots will be roughly the same distance from the main stem as the leaves are at their extremities. Or, to put it another way, if you can imagine potting the plant upside down, with the leaves in the pot, and the roots showing, that's a good way of knowing the right size pot for the plant. (This is not a scientifically accurate measurement of course - it's a very rough rule-of-thumb for visualisation purposes.)

Think of the traditional Chinese foot-binding, which kept women's feet the size of babies' feet. The women were healthy (though in constant pain) etc, but the feet were grossly misshapen and the women could barely walk. Same with plants - squash their roots and the plants will never be quite perfect, and the roots (and therefore the plants) will always be stunted. Baby plants, like baby humans, need plenty of room to spread out and be 'free'!.

I agree with Daisy totally. As I mentioned in another thread, this year I planted the basil in BIG pots (24" x 24") and they are thriving..... I've never had basil get so big and not woody at all.