Grows like a week in the greenhouse. I don't use it much but I grow it in the AP system every year. I haven't tried to figure out growing it outside of it's normal season, I just leave it in it's own grow bed (a 27 gallon tote) and it spreads from 3 individual shoots to fill the tote at least twice a year in the greenhouse (of course I'm not harvesting much so it gets to do what it wants). I rip it all out and start again using part of what I take out. At the price I see it for sale in Asian groceries around here it's probably not worth growing but it sounds like another story where you are (I got my starts from one of the local groceries, you can find galangal, turmeric and other interesting asian vegetables this way - NOTE: Kang Kong is not legal but you may see it for sale, I made a post with more information about Kang Kong a while back).
I replant in the Spring and again late Summer/early Fall - I don't know if this is right but it works for me
. I plant the starts close to one side of the grow bed like you would some types of orchids because the new growth is directional. The plant sits dormant during the winter and survives near freezing temps so you don't have to coddle it unless you want to supply it in the Winter (33F, I've even had the fish tank partially iced over). I'm guessing you'd have to extend the day length for it in the Winter and might need to give it temps at least around 60. It seems to take off slowly in the Spring but comes on when it warms up (sometimes I think the plant looks dead but it isn't)I'm sure there are a lot of Aussies that grow Lemongrass
