Quercus (macrocarpa)

Mark E. Majerus USDA NRCS - Bridger Plant Materials Center 99 South River Road, Rte. 2, Box 1189 Bridger, Montana 59014-9718 (406) 662-3579 (406) 662-3428 (fax) mmajerus@mt.nrcs.usda.gov http://plant-materials.nrcs.usda.gov/mtpmc

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Family Scientific Name:	Fagaceae
Family Common Name:	Oak Family
Scientific Name:	Quercus macrocarpa Michx.
Common Name:	Bur oak
Species Code:	QUEMAC
Ecotype:	Numerous northern Plains seeds sources from Montana, Nebraska, and South Dakota.
General Distribution:	Broadly distributed across northern and central US and parts of southern Canada.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Stock Type:	2+0 40 cubic inch container
Time To Grow:	2 Years
Propagule Collection:	Collect acorns in the late summer or early fall as soon as they mature. Acorns fall to the ground quickly after ripening and are favored by several animals necessitating frequent inspection to prevent loss. Curculio species losses are high in Great Plains sources so it is often necessary to over-collect to meet target production. Curculio damaged and poorly filled seed can be removed by flotation in water.
Propagule Processing:	Caps, if present, are removed prior to sowing. Use flotation in water to remove damaged or poorly filled seed.
Pre-Planting Treatments:	A 60-day cold, moist chilling appears optimum for most seed sources, although some lots germinate with little or no chilling. Imbibed acorns may be chilled in ziplock bags and then sowed or, sowed into media and then cold, moist chilled. We allow acorns to uptake water for 24 hours prior to chilling at 34 to 37øF.
Growing Area Preparation/ Annual Practices for Perennial Crops:	For container production, sow 1 to 2 acorns in 40-cubic-inch containers into a well-drained commercial peat-lite mixwith baseline nutrition. Use tall narrow containers to allow adequate room for root development. Sow acorns so that they are barely covered with media.
Active Growth Phase:	Varies by growing season conditions and, possibly, seed source. Active growth can be maintained with long photoperiods under greenhouse conditions and multiple flushes of growth are possible. Some outplanted trees are capable of a second flush of growth in mid- to late summer but there is no evidence that these trees remain active longer. We have observed that outplanted bur oak tends to break bud late relative to other deciduous species used in the Bridger, Montana area, although fall dormancy/senescence seems comparable with other species.
Hardening Phase:	Move containerized material (at least 2 months old) started in the greenhouse that winter to an outdoor hoophouse in late spring/early summer (i.e. "finish" the plants in the hoophouse). The hoophouse is ventilated but not cooled, and the containers are usually exposed to full sunlight for 2 to 4 weeks early in the season. The hoophouse is then covered with a 50% shade cloth until temperatures cool in the fall. Another option is to finish container plants and rooted cuttings in the greenhouse and then move them to the shadehouse in late summer, allowing 30 to 60 days of hardening prior to winter. The shade is usually removed in late summer/early fall and replaced with clear plastic. The plants harden-off gradually in the hoophouse prior to winter. Bridger is characterized by a high number of solar days that keeps the environment inside the hoophouse relatively mild until winter. In the case of premature and severely cold weather, a small propane heater is used at keep temperatures above freezing.
Length of Hardening Phase:	As a standard practice, we allow a minimum of 30 days of hardening off prior to killing frost, 60 days is preferred.
Other Comments:	Protection of seedlings from animal browsing essential the first several years of field establishment. Container and field production of seedlings, some recent evidence of potential for vegetative propagation from stem cuttings. We prefer containerized stock to bareroot material, and outplanting success of bareroot bur oak from several commercial sources has been poor. Similarly, outplanting success of Bridger PMC bareroot material has been poor relative to container grown plants. Part of the problem at Bridger may be loss of roots due to limitations in the digging capabilities of our equipment. In addition, a much taller and larger caliper plant can be produced in a greenhouse environment at Bridger than in the field.

Citation:

Scianna, Joe. 2003. Propagation protocol for production of Container (plug) Quercus macrocarpa Michx. plants 2+0 40 cubic inch container; USDA NRCS - Bridger Plant Materials Center Bridger, Montana. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/01). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.