One more factor is sunshine to initiate flower bud formation. Last year I was out of the country for part of the summer, so I put pots of Helleborus in deep shade around a small automated sprinkler, so they wouldn't dry out. I moved them when I returned home in the fall, and expected them all to flower in midwinter. None did. I then read that hellebores initiate flowerbuds during late summer, and require light to do this. This year I've left them out in the sun. Rhododendrons make their buds in late summer also. It is very easy to see whether rhododendrons are going to flower in the spring as the round flower buds are noticeable from September. Bulbs are another matter. No sneak preview unless you cut them open. Diane Whitehead Victoria, British Columbia, Canada maritime zone 8, cool Mediterranean climate mild rainy winters, mild dry summers