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Allium (cernuum)

David J. Horvath
Nursery Manager
Illinois Department of Natural Resources - Mason State Nursery
17855 N. CR 2400E
Topeka, Illinois 61567
309-535-2185
309-535-3286 (fax)
dhorvath@dnrmail.state.il.us
gillyflowernursery.com

Family Scientific Name: Liliaceae
Family Common Name: Lily Family
Scientific Name: Allium cernuum Roth.
Common Name: Nodding onion
Species Code: ALLCER
Ecotype: Illinois 650 ft elevation
General Distribution: A. cernuum occurs in meadows or open forests that are moist in the spring; from the prairie foothills to the subalpine; from Alaska across Canada, south to Oregon, and also south to Mexico through the Rockies and the Intermountain West. It is found through out the eastern and Midwestern states.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 1+0 container plugs
Time To Grow: 7 Months
Target Specifications: Height: n/a, herbaceous perennial.<br> Caliper: n/a, herbaceous perennial.<br> Root System: Healthy bareroot system from field grown crop.
Propagule Collection: Seed is collected by hand from nursery stock. The plant flowers from approx. July 13 to August 26. Seed is harvested about September 1.
Propagule Processing: After drying, run the seed through the Dybvig, dry, to separate chaff from the seed. Then it is run overthe Clipper with a top screen of 1/12 and a bottom screen of 1/20 or 1/15. The last step is to run the seed through the Forsberg gravity seed table.
Pre-Planting Treatments: 8 ounces of seed is saved to sow one bench in either 64 flats of the Multipot #6, or 24 flats of the Multipot #3 or #4.
Seed is damp stratified by mixing it with equal amounts of vermiculite and lightly dampening in a plastic bag or container.
Store this seed for 3-4 months in a cold room of 34-36 degrees F.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Propagation Environment: Fully controlled greenhouse.
Container Type and Volume: Multipot #3, #4, or #6 are used. Cell volumes are 6 cubic inches, 9 cu. in. and 6 cu. in. respectively.

Growing Media: Sterile, Pro-Mix PGX. Add vermiculite and perlite at a 10:1 ratio. Mix in 5 ounces of Osmocote, slow release fertilizer, 17-6-10, per cubic foot of soil. Ensure flats are tapped down to prevent settling.


Total Time to Harvest: 7 - 11 months, depending on weather and plant/ root development.

Sowing Date: Three crops are started in the greenhouse with the first in late December and the last no later than the end of March.


Sowing/Planting Technique: Sow the seeds by hand by broadcasting. Try to sprinkle 3 - 5 seeds per cell. Seed purity rates vary from year to year. Thus, it is easier to thin than to transplant. Cover the seeds to one times their depth with the same growing media. Use a dibble board or roller to gently press seed and cover soil in the cell.
Establishment Phase: Set the greenhouse temperatures to be 70-80 degrees F during the day, and 65-75 degrees F at night.
75% germination is reached in about one week.
Plants must be watered by hand during germination. Set the hose on gentle shower to prevent seeds from splashing out.
Active Growth Phase: Once germination is successful, the greenhouse temperature may be turned down gradually depending on outside temperatures. Plants are irrigated in the morning by soaking for 20 to 30 minutes. This allows the foliage to dry out during the day. Once true leaves appear, not cotyledons, the plants may be fertilized. Start with 50 ppm of Rapid Grow or Peter's Liquid Fertilizer once a week. This rate is increased to 200 ppm gradually, and, again, decreased to 50 ppm before moving the plants outside to the shadehouse. It is important to rinse fertilizer residue off the foliage by running the irrigation for 30 seconds. Plants should be thinned to 2 plants per cell. This should be accomplished before the roots are too extensive. When foliage reaches 8 to 10 inches, the plants need to be pruned back to 3 or 4 inches. This is accomplished by turning the flats on their sides and cutting with scissors or sheers. Make sure the clippings are all removed from the flats to prevent disease spread.
Hardening Phase: The first greenhouse crop will be moved to a hoop house in late January to February. To acclimate the plants, the irrigation rate is reduced to 50 ppm before moving and greenhouse temperatures are decreased to 55-60 degrees day. The second and third crops are moved directly to the shadehouse in April and May. Again, greenhouse controls and fertilization rates are adjusted in preparation for the move. Plants that reach 8-10 inches in the shadehouse will require pruning also.
Harvesting, Storage and Shipping: Harvest Date: Flats may be unplugged in October or November as long as most of the tops have died down.

Storage Conditions: Plugs that are not shipped during this fall's planting season may be stored for spring planting in cold rooms above freezing, preferably 40-50 degrees. Try to remove most of the dead foliage as you can before bagging the root plugs for storage. Store them on plastic bags to ensure the roots do not dry out.

Storage Duration: Approximately 4 to 6 months. Plugs may be shipped at any time as long as the receiver has cold storage.
Length of Storage: 4 to 6 months

Citation:

Blessman, Gary; Flood, Roberta Mountz; Horvath, David J.. 2001. Propagation protocol for production of Container (plug) Allium cernuum Roth. plants 1+0 container plugs; Illinois Department of Natural Resources - Mason State Nursery Topeka, Illinois. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/04/18). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.