Phlox (amplifolia)

Shelby J. French Propagation Manager Mt. Cuba Center 3120 Barley Mill Road Hockessin, Delaware 19707 302 239 8819 302 239 5366 (fax) sfrench@mtcubacenter.org http://www.mtcubacenter.org/

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Family Scientific Name:	Polemoniaceae
Family Common Name:	Phlox
Scientific Name:	Phlox amplifolia
Common Name:	largeleaf phlox
General Distribution:	Native to North America, is found in the U.S. ranging from Indiana south to Alabama, from Missouri and Arkansas east to Virginia.
Propagation Goal:	Cuttings
Propagation Method:	Vegetative
ProductType:	Container (plug)
Stock Type:	1 quart container
Time To Grow:	4-5 months
Target Specifications:	Well-rooted 1 quart containers
Propagule Collection:	Cuttings collected week 1 in January and week 7 in February, from non-flowering new shoots.
Propagule Processing:	"Stock plants forced in greenhouse in November, heat set at 15-21˚C (60-70˚F), under 16 hour long-day length high pressure sodium lights. Stock plants hydrated the day prior. Tip cuttings should be taken as soon as new growth is long enough for 2-3 node cuttings, at this length growth is already firm. First set of cuttings taken January 7, second group taken February 12. This species has new growth which is relatively firm. It is best to force growth in a greenhouse versus field-grown stock."
Pre-Planting Treatments:	"Tip cuttings 2.5-3.8 cm (1-1.5 in) in length. 3 nodes, with 1 node below soil. Rooting hormone Dip 'n Grow IBA/NA at 20X dilution rate (1% Indole-3-butyric Acid; 0.5% 1-Naphthaleneacetic acid), 5 second dip. Pro-Mix PGX, plug and germination media. Cuttings stuck one per cell in 72 plug tray 5.7 x 7.6 cm (2.25 x 2.3 in)."
Growing Area Preparation/ Annual Practices for Perennial Crops:	Cuttings are placed in a propagation house with intermittent mist, cycling every 6 minutes with 8 seconds of mist time. 2 weeks after sticking cuttings, frequency of the mist interval is increased to 12 minute intervals. Bottom heat is provided by hot water, in tubes, underneath the flats at 18-24˚C (65-75˚F). Air temperature is set at 17˚C (62˚F) night temperature. Day temperature ranges from 17 - 22˚C (62 - 72˚F).
Establishment Phase:	4 weeks after sticking, rooted cuttings are removed from mist and bottom heat. 5 weeks after sticking moved from propagation greenhouse to a greenhouse with shade covering, heat set at 15-21˚C (60-70˚F), under 16 hour long-day length high pressure sodium lights.
Length of Establishment Phase:	5 weeks
Active Growth Phase:	January cuttings potted 12 weeks from sticking; February cuttings potted 9 weeks from sticking. 98% rooting success. Transplanted into 1 quart fiber pots using a commercial potting media with added synthetic fertilizer. Returned to the shaded, warm greenhouse for 1-2 weeks transplant adjustment, before moving to a full sun exposure in a glass greenhouse. Plants continued to grow all season.
Length of Active Growth Phase:	5 months
Hardening Phase:	"Due to a potting time of February and March, transplants kept in a warm greenhouse at 15-21˚C (60-70˚F) until early summer. Plants then moved outside in summer and overwintered in an unheated poly-house the following year."
Outplanting performance on typical sites:	Plants ready to be outplanted 8 weeks after first potting, 16-20 weeks from sticking. Plants could likely be pushed to be ready sooner.
Other Comments:	The key to identification from Phlox paniculata is the long corolla tubes, and presence of pubescence on its wide leaves, and stems. Species appears resistant to powdery mildew.
References:	Lady Bird Johnson Wildflower Center. (2017-11-16). Retrieved from https://www.wildflower.org/plants/result.php?id_plant=PHAM7 Missouri plants. (2018). Retrieved from http://www.missouriplants.com/blueopp/Phlox_amplifolia_page.html Mt. Cuba Center research report. (2017). Retrieved from https://1x848d9mftq5g9wx3epiqa1d-wpengine.netdna-ssl.com/wp-content/uploads/2017/12/MtCuba-Phlox-Report.pdf Nature Serve Explorer. (2018) Retrieved from http://explorer.natureserve.org/servlet/NatureServe?searchName=Phlox+amplifolia U.S.D.A. Natural Resources Conservation Service. (n.d.) Phlox amplifolia. Retrieved from https://plants.usda.gov/core/profile?symbol=PHAM7 "Weakley, A. S. (2015, May 21). Flora of the Southern and Mid-Atlantic States. Retrieved from http://www.herbarium.unc.edu/FloraArchives/WeakleyFlora_2015-05-29.pdf"

Citation:

French, Shelby J.; Kniola, Ryan. 2020. Propagation protocol for production of Container (plug) Phlox amplifolia Cuttings 1 quart container; Mt. Cuba Center Hockessin, Delaware. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/02). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.