Ask Alys: why did my pyracantha fail to produce berries?

Our gardening expert Alys Fowler has the answerFor the first time in 40 years, my two pyracantha bushes have produced no berries. Is there a reason for this? Can it be corrected?
Did you prune them? A hard pruning will mean few flowers the following year, because pyracantha, aka firethorn, flower on last year’s growth. If you cut them back hard at the wrong time you can unwittingly remove all the flower buds.If you haven’t been pruning them, I can only think that