Correct taxidermy guy, such periods of inactivity have appeared to coincide with the accumulation of white precipitation on the ground. The indians, wise in the ways of such matters called those periods of time when plants looked dead and refused to grow, VANTERTYEME, or in the modern tongue, WINTERTIME and instinctively realized that even though plants may appear dead when covered with snow during the months of dec-march they may in fact be very much alive. Thanks for pointing this important yet not commonly known fact out.

HAHAHA. Couldn't resist tax man.

Mike don't know about oak trees, but I do grow alot of other indoor plants from seed and cuttings. Only thing I can say is try and move them out of the coffee cups and into something with very good drainage.
Also don't water to often and wait till dirt gets dry before watering again. Biggest
killer of all the new plants is fungus, mold etc and they like water.Also leaves turning yellow can indicate over watering. Most common problem with all new plant growers is overwatering which then leads to everything else. Good luck.