How long till they get massive?

I say 6 weeks to 8 weeks.

Bit over 16 days old outdoor
Special kush #1 fem

Its going to be quite sunny here in aus

You've got some time.

Massive is a relative term, but yes, it could be a xmas tree by two months. And out of curiosity, which part of the Aussieland do you reside, an arid or humid area?

Those are SO small for 16 days. I forsee many many problems in the future.

Massive to you could be a runt to others .....I'm usually not getting to thrilled until my outdoor girls are hitting the 7ft tall mark and at least 4ft round and that takes a few months for me .....but I do like a 4ft plant that's 8ft round also easy to tend to ......this year I have several well over 9ft and a sativa dom that's pushing 10 ......which is a bitch to have to carry my painting ladder through my garden to check my girls out from time to time .....but give it a few months and with good training and grow techniques I hope you have the same issue ......GL

Ty a lot