This about is the same scenario as my other question Do spring-flowering bulbs inhibit the growth of other plants? so I won't repeat the details.
In the past few days (last week of August), I have healthy-looking crocus leaves appearing months before they should be starting to grow in spring.
I thought the growth cycle was triggered by warming soil temperatures after winter, but this obviously doesn't apply here. The UK summer weather has been hotter than average, but otherwise fairly normal.
The bulbs were originally bought from a supermarket, not named varieties but labeled (correctly) by color, and definitely not as "autumn flowering crocus." In any case, autumn flowering crocus produce flowers before any leaves appear.
Any ideas what might be the cause of this?