Irises: % of iris seed germination, 1 by

wrote:
If this is about Bearded Iris seeds, I would say that germination depends on how long seeds were stratified and the inhibiting factor removed. Might be genes also.

Soak seeds in hand hot water overnight. Allow to cool. Seeds need to remain in the water for at least 3 weeks. Change the water out daily using a strainer to catch the seeds (so as not to lose any). No nicking is necessary. This soaking and rinsing treatment is to remove the seed germination inhibitor present in the seed or seed coat. Outdoors, the fall rains and melting snow in winter do the same thing over a 3 to 4 month period.

Sow Iris seeds in pre-moistened potting soil 1/2" deep in a container such as plastic shoe boxes (cheap in Walmart). I covered the containers and left them out all winter long on North side of my house. Iris seeds require 12 weeks of less than 40 degrees temperature to break dormancy. They will sprout during spring when temperature reaches 55 to 70 degrees. Check the box during spring and plant any that sprouted in a 2” or 3” pot. Grow them under plant lights until all danger of frost is gone in your area. Harden them off. Then place the pots outdoors to get some more growth before planting in the ground. Feed with plant food low in nitrogen, 5-10-5 is good at ½ strength. First number is nitrogen.

If you are in a hurry to get them to sprout and gain more growing time, bring the box in to room temp early spring. The seeds will soon begin to sprout at higher temperature.

I brought the box of seeds indoors in April and placed under lights. The seeds began to germinate in one week. Every seed germinated to my surprise. I have another box of Iris seeds from my crossed in a plastic shoe box this year also, as shown below.