In 1903 it was recorded in Notes & Queries that:

A blossom on the tree when the apples are ripe                                                     Is a sure termination of somebody’s life

In common with other fruit trees it was believed that if an apple (Malus pumila) tree flowered out of season misfortune or death was foretold.

[1872] Remarking in an apple blossom a few days ago, month of November, on one of my trees I pointed it out as a curiosity to a Dorset labourer, ‘Ah! Sir,’ he said ’tis lucky no women folk be here to see that’; and upon my asking the reason he replied ‘Because they’s sure to think somebody were a-going to die.’

[1929, South Moulton, Devon] we had apples and blossom on one branch of the tree one September, and were told it was a sign of death.

[1987, Reading, Berkshire] If an apple tree blossoms very much out of season it foretells a tragedy in the family before the year is out.

[1993, Fleet, Hampshire]  My mother has mentioned the superstition that apple blossom on the tree in August, with fruits, is a bad warning of death in the family.  This was certainly then alive in the village of Crondall … where she spent her childhood in the 1920s.

Image:  cultivated, kitchen garden, Audley End House, Essex; September 2016.