MoraniWine: Buds are initiated in the middle of the summer, not in the fall when there is cool nights. These cool fall nights...etc for bud inducton is wrong. By the fall, it is already too late to induce the buds. Once the buds are induced and they are grown about 3cm-5cm, I cover it with aluminium foil cap (around mid October). Then here are the rules:
green flowers (all Chinese varieities): No Cap is required.
Purple flowers: No Cap is required
Orange, Yellow, White: cap it until 2 weeks before blooming in the spring.
Red: the cap is removed anywhere between mid Dec to mid January, depending on the variety. This you have to ask the vendor, specifically for the clone.
From mid Dec, C. goeringii are grown between 0C-10C at all times (no higher and no lower) for an extended period of time. It is called vernalization. During vernalization process, this is when the buds start to grow and getting fatter. By mid January, the buds should get very fat and the flower stem should start to elongate. This is also the time to check if the capping works, at this time, you should start to see the flower petal colours through the flower sheath.