In the 1920's some 200 willow setts from Cowfold & Beltring were planted opposite the cricket field in Robertsbridge, but they were found to be hard and of poor quality. More recently however a tree was cut in Robertsbridge that was nearly fifty inches around the trunk after only nine years. Len Newbery, who was manager of Gray Nicolls until his death in 1976 said "The timber of the salix alba caerulea is distinguished by a bright orange stain that is known in the trade as the butterfly stain. when these stains appear on the blades of bats the players often reject such bats thinking that they are faulty whereas they are the hallmark of simply the finest willow."
50" circumference trunk in 9 years, that pretty fast growing.
That's about 16" diameter, splits down into 8" clefts with 9 grains. Chop off the inside wedge and cleanup the bark edge and that'll give you roughly 4 grains. Reckon it'll ping like a trooper.
I also see the price of butterfly going through the roof, expect it to reach £400+ in the next year or so for a finished bat.