Last year I collected several hundred seeds from our local native columbine (Aquilegia formosa) in Thurston County. I recently planted some in commercial seed-starting mix in my small greenhouse. Could you tell me the best methods for storing and germinating these seeds as well as some of the native tiger lily?
In general, seeds should be stored in a dark, dry, cool place. I have had good luck storing extra seeds in a sealed jar or bag in the refrigerator, but this is not always recommended, because it is damp. According to Seeds by Jekka McVicar, columbine seed is generally viable for five years. McVicar suggests placing flats outside in fall and leaving them out all winter, since the cold helps to prepare the seeds for germination in spring. Alternatively, “in late summer fill tray or pot with compost, smooth over, tap down, and water in well. Use fresh seed (…) sowing the seed thinly on the surface of the compost. Cover with perlite or vermiculite (…)Place the tray or pot in a warm place out of direct sunlight at an optimum temperature of 50 degrees. Keep watering to a minimum until germination has occurred, which takes 14-28 days with warmth. Prick out into pots. (…) Overwinter young plants with a bit of protection in a cold frame.”
Eileen Powell, author of From Seed to Bloom, suggests refrigerating the seedling trays for two to three weeks and then sinking the flats into the ground in a shady location, covered with glass, and transplanting seedlings as they appear. She also says “seedlings are delicate; keep out of strong sunlight and water gently.”
Neither of these authors discusses our native columbine. However, Propagation of Pacific Northwest Native Plants by Robin Rose et al. suggests an easier method for Aquilegia formosa: “Seeds can be stored for up to two years at a low temperature and humidity or longer in sealed containers in low moisture. Prechilling for three days is required for germination. Direct seed in spring or fall. (…) Plant in containers or scatter evenly over a seedbed (this is made easier by first mixing the seeds with fine sand). Cover with a very thin layer of soil or weed-free compost and keep moist. Seeds should germinate in two to four weeks.”
As for propagating the native tiger lily, Lilium columbianum, Plants for a Future database provides directions, excerpted here:
“Seed: autumnal hypogeal germination. Best sown as soon as ripe in a cold frame, it should germinate in spring. Stored seed will require a warm/cold/warm cycle of stratification, each period being about 2 months long. Grow on in cool shady conditions. Great care should be taken in pricking out the young seedlings, many people leave them in the seed pot until they die down at the end of their second years growth. This necessitates sowing the seed thinly and using a reasonably fertile sowing medium. The plants will also require regular feeding when in growth. Divide the young bulbs when they are dormant, putting 2 – 3 in each pot, and grow them on for at least another year before planting them out into their permanent positions when the plants are dormant. Division in autumn once the leaves have died down. Replant immediately. Bulb scales can be removed from the bulbs in early autumn. If they are kept in a warm dark place in a bag of moist peat, they will produce bulblets. These bulblets can be potted up and grown on in the greenhouse until they are large enough to plant out. Stem or leaf cuttings.”
Here is what Kathleen Robson et al. have to say in Encyclopedia of Northwest Native Plants for Gardens and Landscapes (Timber Press, 2007): “Propagation: collect seeds in the late summer after capsules have ripened. Plant them within a few weeks of harvest, either directly into the garden or into deep containers, and leave them outside in the cool, moist winter weather for germination the following spring. Seedlings will take several years to reach flowering size. Those that were sown in containers can be left in them for part of that time; it may be easier to protect them from slugs.”