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The Forest Service National Center for Reforestation, Nurseries, and Genetic Resources (RNGR) is a leading source of technical information for nurseries and land managers regarding production and planting of trees and other native plants for reforestation, restoration, and conservation.

 
NPN Protocol Details Image

Helianthus (annuus)

Andrea Kramer
Conservation Scientist
Chicago Botanic Garden - Research
1000 Lake Cook Road
Glencoe, Illinois 60022
847-835-6971
akramer@chicagobotanic.org
http://www.chicagobotanic.org
Family Scientific Name: Asteraceae
Scientific Name: Helianthus annuus
Common Name: annual sunflower
Species Code: HEAN
Ecotype: wild-collected from Garfield County, Colorado
Propagation Goal: Seeds
Propagation Method: Seed
ProductType: Propagules (seeds, cutings, poles, etc.)
Pre-Planting Treatments: APPROACH: This project aimed to determine optimal germination conditions for species currently used in restoration in the Colorado Plateau, as well as other priority forb species that may be beneficial to include in future restoration efforts. For this study, seeds were plated on 1.5% agar in petri dishes (4 replicates of 25 seeds per treatment) and incubated in growth chambers at Chicago Botanic Garden using six temperature treatments intended to represent different seed sowing times and locations in the Colorado Plateau (treatments are shown as day/night temperatures respectively, using a 12h/12h light/dark cycle):

TREATMENTS:
1) early-spring (4 weeks at 52°F/34°F)
2) winter (12 weeks at 34°F) and early-spring (4 weeks at 52°F/34°F)
3) mid-spring (4 weeks at 59°F/41°F)
4) winter (12 weeks at 34°F) and mid-spring (4 weeks 59°F/41°F)
5) late-spring (4 weeks at 68°F/50°F)
6) winter (12 weeks at 34°F) and late-spring (4 weeks 68°F/50°F)
Establishment Phase: RESULTS: Viable seeds from this wild-collected seed from Garfield County, Colorado germinated to only 40% or less in all three treatments that imposed 12 weeks of winter conditions (treatments 2, 4, 6). Treatments without winter conditions (treatments 1, 3, 5) had even lower germination (0-15%). This suggests that seeding during late winter or early spring will not provide sufficient dormancy breaking to allow seeds to germinate. Additional research is needed to confirm the specific length of winter conditions needed to break dormancy and allow germination. The figure at http://tinyurl.com/CBGSeedGerminationHEAN shows the average percent germination and standard deviation of viable seeds for each treatment.

Citation:

Kramer, Andrea T; Foxx, Alicia. 2016. Propagation protocol for production of Propagules (seeds, cutings, poles, etc.) Helianthus annuus Seeds Chicago Botanic Garden - Research Glencoe, Illinois. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/03). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.