Blossom end rot

Blossom end rot

© CavinB

Type: Other

Blossom end rot

A sunken, dark patch at the end of fruit where the petals were indicates calcium deficiency. This causes cells to swell and burst. As a lack of calcium in soil or compost is rarely a problem, it is almost always due to inadequate distribution of that calcium around the plant by water - either because of insufficient water at the roots or too little transpiration (loss of water through the leaves).


  • A dark (yellow, green, brown or black), often sunken, patch at the end of the fruit where the flower was
  • Tends to affect the earliest trusses and larger fruited varieties more seriously

Prevention & control

  • Never allow compost/soil to dry out, ensuring a good supply of water - mulches can help and plants in large containers or borders are less susceptible to drying out
  • Ensure good ventilation under glass to encourage transpiration
  • Avoid over-application of fertiliser, particularly in dry conditions as this can hinder the uptake of water
  • Remove and compost affected fruits
Top tips
Login or register above to add your own tip.