Unless you've chosen a metal halide or high wattage compact fluorecent - like the 200W Envirolite - your growlight will do more harm than good. It's unlikely you've got the appropriate equipment for indoor tree fern cultivation unless you've invested heavily in hydroponic-grade lighting, and plenty of it.

For a variety of reasons tree ferns almost always have to be grown outdoors. Keeping them indoors longterm requires the kind of growroom investment that is unrealistic for all but the fanatic.

Steve Pope - UK

I have a similar question. I imported 2 - 30cm Dicksonia Antarticas and have had them in my basement around 72 degrees (F) since January. One has produced two large fronds, and 1 tiny frond curl is forming. And the other has 4 fronds that are almost full length. I finally took them outside 2 weeks ago because we were having beautiful weather in the 70's, and I placed them (still in their pots) in my fern garden area. The nights haven't gone below the 50's. But it seems their frond growth has stopped, and made no progress. Was this too much of a shock for them? Should I bring them back inside? Do I need to fertilize? Thanks for any tips. These will eventually live outdoors all year, and I'm in Maryland, USA.