John M. Englert
Natural Resources Conservation Service - Norman A. Berg National Plant Materials Center
Bldg. 509, BARC - East, E. Beaver Dam Road
Beltsville, Maryland 20705
|Family Scientific Name:
|Family Common Name:
||White heath aster
||Great Smoky Mountains National Park
||Maine and Nova Scotia to Georgia, west to Wisconsin, Iowa, Kansas and Arkansas. Found in dry fields, waste places, and sandy soils.
|Time To Grow:
||Stock Type: Container plugs.
Height: 4-6” at outplanting after cutbacks.
Root System: Firm full plug; roots fill container.
||Collected in Great Smoky Mountains National Park, NPMC seed production block.
||Seed Processing: For aster species that are grown in NPMC production fields, seed is harvested with a modified Trac-Vac which removes only the seed with pappus from the stem. Seed may also be harvested with any other vacuuming process such as a shop vac or modified leaf blower. In cleaning, the pappus is removed from the seed by a debearder modified by NPMC staff for small seed lots. For ease of cleaning, large seed lots are first run through a large clipper before being further refined in a desk top clipper. Either machine will need a solid bottom screen and top screen with holes large enough for the seed to fall through. Fan speed is set low enough to blow only empty seed out.
Removing the pappus from the seed of aster sp. reduces the cleaned seed weight approximately by 10 times and will require adjustment in seeding rates since seed with pappus may produce 240 plugs per gram while seed without pappus may produce up to 2,000 plugs per gram.
Seeds/Kg: Estimated at 2-5,000,000. 100 seed weight has varied from 0.013g to 0.05g.
Purity: 98.6 to 99.9%.
||Seed Treatments: Seed germinates in light, therefore it should be surface-sown.
|Growing Area Preparation/
Annual Practices for Perennial Crops:
Propagation Environment: Greenhouse with alternating day/night temperatures; daytime temperatures varied from 70-90ºF depending on natural solar; night temperatures averaged around 65-68ºF. Plugs were grown under 14-16 hour long day conditions using high pressure sodium lighting from 4:30-10:30 p.m.
Seed Propagation Method: Seed was hand-sown into germination trays. If seed had pappus still attached it was surface sown over tray cells in small clumps. Cleaned seed without fluff was mixed with talc and surface-sown using a salt shaker.
Container Type and Volume: Seed is started in 392 or 406 germination plug trays. See Sowing Technique for further discussion. Seedlings are transplanted into Ropak Multipots (67 cell) or 72 trays.
Growing Media: Seed is sown onto germination mix. Seedlings are transplanted into Sunshine #1 (72’s) or #5 (multipots). The potting mix is amended with 18-6-8,180-day Nutricote SR (0.15 lb./cu. ft., or 20 oz. per 3.8 cu. ft. bale of potting mix).
||Sowing Date: Winter, or summer, depending on time of planned outplanting in the spring.
% Emergence and Date: Using the protocol described below most of the seeds that will germinate have done so within 4 to 7 days.
Sowing/Planting Technique: Seed is small and difficult to sow evenly. Seed germinates in light, therefore it should be surface-sown. If pappus is left on the seed, sow in clumps. If pappus has been removed, cleaned seed can be mixed with talc and sown using a salt shaker. Uniformity of germination is greatly enhanced by keeping seed trays moist and warm. During the winter, trays were covered with clear plastic and placed on heat mats set at approximately 75ºF. Using this protocol, seedlings emerged in about 3-5 days and germination was thick (many multiples per cell). Seed trays sown during the summer were put under mist and emergence of target number of seedlings occurred in 11 days. We have not direct-sown aster seed into final containers in the past because cells have germinated irregularly or too thickly and there is often uneven growth and maturation of the seedlings. Selecting plugs from the germination trays that are at the same stage of development provides reasonable assurance that contract goals and deadlines will be met.
Establishment Phase: Seedlings in germination trays need to be kept evenly moist. We have put trays under mist, but slowing of growth has occured if left too long. Pulling plugs is easier if there are multiple seedlings in each cell and this can be done early. Seedlings seem to grow more rapidly the sooner they are bumped up to plug trays with larger cells, potting media and fertilizer. Thinning of crowded seedlings may be required to allow one seedling to dominate the cell.
|Active Growth Phase:
||Rapid Gowth Phase: Transplanted plugs are lightly fertilized approximately bi-weekly, or as needed, with a soluble fertilizer (Technigro 16-17-17 @ about 100 ppm). Cutbacks are performed to keep top growth uniform and strong, to prevent shading of smaller leaves, and to control insect pests and fungus. Foliage does attract typical greenhouse pests (aphids, mites, whiteflies) so treatment may be needed.
||Hardening Phase: Approximately 2 weeks prior to outplanting, temperatures are reduced in the green house or plants are moved outdoors to a sheltered location, weather permitting, and fertilization is stopped.
|Harvesting, Storage and Shipping:
||Harvest Date: Seed is harvested from the NPMC production block in November or December, after some frosts. Plugs are outplanted in the spring or fall.
Total Time to Harvest: About 10-12 weeks from germination to finished plug.
Storage Conditions: Usually plugs are grown and planted in the same season. This year we will be overwintering finished aster plugs in cold storage
@ 40ºF, 35% relative humidity for 4 months.
Seed storage: cleaned seed is stored in cloth seed bags in the NPMC seed cooler @ 40ºF, 35% relative humidity.
|Length of Storage:
||Storage Duration: 4 months.
|Outplanting performance on typical sites:
||Outplanting Site: GRSM in spring, 1998; NPMC seed production block was established with plugs and divisions.
Outplanting Date: Spring in the park, spring or fall in the NPMC field production blocks.
||Brown, M. L. and R. G. Brown. 1984. Herbaceous Plants of Maryland. Port City Press, Inc.
Gleason, H. A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada, 2nd edition. New York Botanical Garden.
|Davis, Kathy M.; Kujawski, Jennifer L. 2001. Propagation protocol for production of container Aster pilosus plants (1+0 containers); Natural Resources Conservation Service - Norman A. Berg National Plant Materials Center, Beltsville, Maryland. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 4 July 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.|