diff --git a/assays/complementation_crosses/protocols/crossing_plants.md b/assays/complementation_crosses/protocols/crossing_plants.md
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..b090a5eaae8dcffaacb3650b63cc5c1021045968 100644
--- a/assays/complementation_crosses/protocols/crossing_plants.md
+++ b/assays/complementation_crosses/protocols/crossing_plants.md
@@ -0,0 +1,10 @@
+**crossing of plants**
+
+- grow parent plants in LD conditions
+- if parental plants have very different flowering times: sow the faster one with a bit of delay)
+
+
+- emasculate florets from mother plants before pollen are shed (about Waddington stage 8.5 - 9.0)
+- pollinate florets with pollen from father plants, pollinate all florets from one spike with the same father: this is one cross
+- cover the spike with a paper bag, count later how many of the pollinated florets develop into seeds
+- harvest seeds from each spike / each cross individually when they are completely dry
\ No newline at end of file