William said: Once in ground they seem to immediately start to grow new roots (yes I do dig and check these things 
).
I agree/can confirm this. I got a lot of bulbils from Tiger Babies. I picked off around 20 of them (there's still a bunch still on the stem) and potted them up, none had leaves (and still don't) but they started growing a lot of roots last a looked (about a month after planting...I also went poking around) and seemed to have increased in size a fair bit compared with the ones still on the stem.
Australis said:What else (other than damage to the stem) can trigger bulbil production?
Complete guess but it wouldn't surprise me if heat stress is a trigger.
