Seeds – Stratifying

Stratification is a treatment of seeds used to jump-start them to germination.

Many plants need a period of winter chilling to break the seed’s dormancy for spring germination.

Stratification achieves this artificially – most commonly by simply exposing seeds to cold.

Cold Moist Stratification 

  • benefits many species, including fuchsia, sedum buddleja and lavandula
  • place seed in a clear plastic bag filled with moist (but not wet) coir, somposted bark, or equal parts of these with coarse sand, perlite or vermiculite.
  • seal the bag and chill in a refrigerator below 5 degrees C for 4-20 weeks.  The time depends on the type of seed so seek guidance on the particulars.
  • shake the bag periodically.  If you see signs of germination within the bag, then sow immediately.

Warm Moist Stratification 

  • benefits actaea and some lilies
  • place seed in a bag as above.
  • keep in a warm place (such as an airing cupboard) at 18-24 degrees C for up to 12 weeks.
  • move the envelope to the fridge and provide a spell of cold stratification as above.
  • plant out when you see signs of germination.