Different question about strawberry runners

Does the crown come after the plantlet has established itself or when pegging  down the plantlet should you still be careful not to bury the immature crown.

I seem to be doing it right as have loads this year and last year that worked very few that just rotted.  I wondered if the ones that rotted were because I had buried the crown if it has one.  Although it was probably because cut too soon from mother.  It doesn't happen often i.e. 4 out of 40 runners.  Can't help counting them something for nothing.

Thanks for that Trill

To the young plant, it does matter how soon the runner is cut off. The young plant needs a bit of time to establish, so it draws food from the parent plant for a while as it sets its own roots. The time to cut is when the young plant looks like it has a modest root system for self support.
As for the mother plant, when you cut off the young plant is of no matter to it. A strawberry plant's lifespan is only 5 yrs max which is why it reproduces with runners. Mother plant's yield however is definitely affected by whether or not you cut off the older, reddening leaves after fruiting; these suck up needed food by the crown part. These leaves were the old fruiting leaves and must be trimmed off and the plant fed with compost or aged manure, and watered if dry. This rejuvenates the mother plant for next season. Progressively her yield dwindles until she eventually dies off regardless of treatment.
Re feeding - never feed prior to fruiting as this makes very soft fruit that easily molds. Feeding is necessary after fruiting is finished.