A secret message?

There are two Silver Banksias Banksia marginata growing in my garden, and they've been coming up to full flower the last couple of weeks. (Banksias take a while to come to the point.)

And last week I was holidaying 300 km away, and in my favourite bit of heath the Silver Banksias are coming up to full flower. How do they do it? What triggers the mass flowering? And why do they flower now, when very little else in the bush is flowering?

I'm not complaining. The sight of numerous shrubs covered in yellow spikes is a joy that I look forward to every year.