White Widow auto isn't blooming!

[swirlhorse]

Hey everyone. First time grow with these Crop King White Widow Autoflower. Planted them in pots outside in a greenhouse on June 1st. That's about 40 days ago. Plants are doing very well. most are all over 4 feet tall and quite bushy. The greenhouse is facing south west so gets sun from 8am to 5 or 6pm.I am feeding them a 18-18-21 fertilizer about once a week.

Problem: no buds!

What am I doing wrong?

 

[Bloodguy]

I'd be wondering if they weren't photo plants.

 

[AnimaSola]

That's not much light for an auto, autos like 18 to 24 hours of light a day.