Looks like your soil may be too heavy , I mean did you prepared a mix between your garden soil and dsme potting soil or some peat or anything to improve the a tual structure of your soil ? It is an outdoor issue , If the plant can't break the soil she won't grow that is way you need to prepare and improve it with nutrients ( compost is a good start ). What amount of light a day she is receiving ? Because if it is less than 18h she will flower pretty quickly even for an auto. I also advise you to spray your plant with water because that dusts on the leaves is not the best way to improve the photosynthesis