Yes. Something I have not tried before. So it's like going from 18/6 day/night to 12/12 day/night. In April that days are pretty short and a plant inside in veg that gets put outside will respond to the light change. If the plant is shocked into thinking winter is coming, it will begin flowering and continue through the solstice and into the end of summer (supposedly - I have not tried it myself). This is good for long flowering sativas, which I am fond of. I have a pile a clones and am going to give it a try!And this is why I don't grow in HB!
How can you get an outdoor plant to flower early? Mine in L.A. don't start showing pistils until mid-July, about 4 weeks after the summer solstice.
Also @Archiweedies if you put a small light near your plants when you go outdoors, you can flip it on in the night to keep plants from going into flower when you put the outside. But I think @Norcaliwood says if you go outside with an established clone (from 18/6) on June 10, it seems like it just keeps on growing, so that is my plan for the Black Dog. Get her as big as I can indoors and outside she goes on June 10.