Icelandic poppy seeds can be tricky to germinate, but we are getting great results with the following method: Surface sow, do not exclude light. 50-60F is ideal. 288 cell trays are usually recommended, micro soil blocks, and 1 1/2" soil blocks have worked for us. Dusting the soil surface with fine vermiculite and then sowing gives a moist evironment without covering the seeds which need light to germinate.
Use domes during germination period. Sowing with the moistened end of a toothpick is the best way to deal with these tiny seeds. Bottom water. Germination can be sporadic, but can begin within 5-7 days. Do not allow soil to dry out during the germination period. Remove domes once seeds have germinated.
Properly hardened off plants can be planted out after about a month. They will tolerate a light frost, but frost protection is beneficial. Spacing 9-12", drip irrigation is best; moist but not wet. Icelandic poppies like good drainage. These are cool growers and do especially well in moderate climates. Where summers are hotter they are good spring and fall performers. In hotter climates, plants started in February and given adequate care during the growing season can bloom from summer to frost and return and bloom the following spring. Summer sown plants planted out in fall will overwinter (Zone 2 and higher) and bloom early summer to mid-fall if picked regularly. Icelandic poppies are treated as biennials where summers are hot and short-lived perennials where summers are cooler. Sowing each year ensures a good crop.
Harvest is done at the cracking-bud stage. Cut and sear stem ends with boiling water or a propane torch. Flower food gives a longer vase life, 5-7 days. Cut poppies at cracking bud stage can be kept in a holding solution in a 4C cooler for a week without diminished vase life.
Icelandic poppy seeds stored dry and sealed in a refrigerator can be kept up to 4 years without significant loss of viability.
