Even though the nutrients might last for 3 months, the lime which buffers the ph of the soil probably ran out already (usually takes 6-8 weeks, coincidentally )

Wait until just before your next watering and pot up to a 5 gal or put in the ground, whichever suits you better. I'd rather use the pot in case they need to be moved at some point.

I would also stay away from the time released nutrient soil, some regular potting soil (not topsoil) with 25% perlite mixed in will do fine.