I'm completely new to rooting fig cuttings. I have bits of leafing from my twigs but there is no guarantee that the rooting are progression as nicely since my cups are opaque. I started these in potting mix in 18oz cups, set in a dark basement. My questions are:

-How much longer should I leave them in the dark?
-At that time, is it better to transition to an indoor light (fluorescents?)
-At what point, do I start hardening them off to take them outside?

Mine are super babies right now... I thought I had read somewhere to leave them in the dark to get the best roots but the leaves are starting to look yellow so I don't think that's the right thing to do?

 

The majority of people say that leaf development is not an indication of root development.

I for one agree since I used Coir for rooting I saw new leaves forming before any signs of roots showed. How long ago did you start these cuttings?

Try to keep the temperature in the 80's and humidity around 100% and keep them out of direct sunlight and out of darkness and they will be fine. I like natural light as it provides a full spectrum for the leaves to photosynthesize. I keep mine under intermittent mist in the outside shaded from direct sun for the first 6 weeks then I transplant to potting soil and partial sun and water the plant and leaves twice a day under irrigation for another 2-4 weeks.

It's fine to start them in the dark but as soon as there's a hint of green you want to give them as much light as possible.  This helps the leaves produce food for the plant, which can help it put out roots.  Since there may be no roots you want to keep the heat down (mid 70s).  If your leaves have developed in the dark they will quickly fry if exposed to sunlight.  T5 or T8 fluorescent bulbs are the usual choices but HIDs and others can be made to work.  Watch the amount of heat so you're not evaporating more from the leaves than can be resupplied by the plant or environment.  A cheap T8 shoplight ($11 @ Walmart) with 2 5000K bulbs or 1 3500K and 1 6500K provides enough light for a young plant to keep the growth from being weak and lanky while not getting too hot.  You want them under that light ASAP.  Start with 10 hrs a day.  If some plants wilt it means they have no roots and they should be further away from the light source.  Be sure the soil isn't too wet.  Generally if you have a small leaf here and there there may not be roots but if you have an explosion of growth there are probably roots.

Agree with rcantor mostly.  Although if you are rooting this time of year, outdoors is a viable (and cheap) option.

Definitely want them in some light.  Ideal would be outdoors in a location that doesn't get any direct sun or rain, but that is fairly bright otherwise.  If that's not an option, put them under some grow lights.

If you don't, then any leaves that form will sunburn and drop off when you put them outside later.  That isn't the end of the world though, they will likely recover if that does happen.