Valley Oak (Quercus lobata)

Distribution map for Valley Oak:• Endemic to valley habitats of California (in fertile lowlands in deep rich soils between the Sierra Nevada and the coast)

• May be the largest N. American oak

• Can live to 400-600 years

• Massive trunks (over 2 meters in diameter)

One meter diameter trees may be “only”150-250 years old

• Can grow to 30 meters tall

• Grows very rapidly in mesic sites where roots can

* 501 Oak AveQuercus lobata DBH = 6’5”!

On the City of Davis Landmark Trees List

According to the City of Davis Master Tree List:

valley oaks make good street and parking lot trees and have a moderate growth rate.

Landmark Trees may be so designated because they are unique in being:

• An outstanding specimen of a desirable species

• One of the largest or oldest trees in Davis

• Of historical interest • Of distinctive form

Using the Trunk Formula Methodof Tree Appraisal by the CTLA (Council of Tree and Landscape Appraisers), and species ratings by

Regional Groups

The Appraised Value for the Valley Oak at:

501 Oak Ave Davis, Ca

= $97,400

(from a whopping $193,300 prior to personal speculation on tree location, placement and health!).

*According to the “Street Tree Planting Guide”provided by the City of Sacramento Urban Forest Services Division(of the City of Sacramento Department of Parks and Recreation):

• Valley Oaks average 50-70’ height and canopy spread

• Are rounded in shape

• Deciduous

• Drought tolerant

• Are ‘fair’ in terms of root suitability to confined spaces

• Are poorly suited to canopies in confined spaces or in conflict with overhead wires

• Are the largest valley native.

• And, should not be planted in turf areas.

According to USDA (United States Department of Agriculture)

NRCS (Natural Resources Conservation Service) Plants Database: http://plants.usda.gov/

Classification: Quercus lobata Née (also called California White Oak)KingdomPlantae ‒ PlantsSubkingdomTracheobionta ‒ Vascular plantsSuperdivisionSpermatophyta ‒ Seed plantsDivisionMagnoliophyta ‒ Flowering plantsClassMagnoliopsida ‒ DicotyledonsSubclassHamamelididaeOrderFagalesFamilyFagaceae ‒ Beech familyGenusQuercus L.‒ oakSpeciesQuercus lobata Née ‒ valley oakRelated Taxa: 6 genera in Fagaceae, 206 species in Quercus

Morphology/Physiology:

Active Growth Period: Spring and SummerGrowth Form: Single Crown Shape and Orientation: RoundedHabit: deciduous treeGrowth Rate: Rapid Height at 20 Years, Maximum (feet): 35 Height, Mature (feet): 100.00Resprout Ability: Yes

Growth Requirements:

Adapted to Coarse Textured Soils: Yes Adapted to Fine Textured Soils: No Adapted to Medium Textured Soils: Yes (Prefers medium loamy and heavy clay)Anaerobic Tolerance: NoneDrought Tolerance: Medium Fertility Requirement: Medium Fire Tolerance: Low Frost Free Days, Minimum: 200 Moisture Use: Medium pH: 4.50 ‒ 7.50 (most any pH)Precipitation, Minimum: 16 Precipitation, Maximum: 40 Root Depth, Minimum (inches): 42 (Plants produce a deep taproot and need to be planted out

into their permanent positions as soon as possible, in fact seed sown in situ will produce the best trees. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.)

Salinity Tolerance: NoneWind Tolerance: HighShade Tolerance: Intolerant Temperature, Minimum (°F): 7 (hardy to zone 7)

Reproduction:

Bloom Period: Early Spring (flowers monoecious, wind-pollinated

Fruit/Seed Period Begin: Summer Fruit/Seed Period End: Fall(Seed ripens in the first year, good crops every 2-3 yrs.)

Suitability/Use:

Berry/Nut/Seed Product: No Christmas Tree Product: No Fodder Product: No Fuelwood Product: High Lumber Product: NoNaval Store Product: No Nursery Stock Product: Yes Palatable Browse Animal: Low Palatable Graze Animal Palatable Human: No Post Product: No Protein Potential: Low Pulpwood Product: No Veneer Product: No

Hookers Valley Oak

*FORMORLLY A DOMINANT SPECIES IN THE CENTRAL

VALLEY:

• Used to occur in extensive park-like groves

• Common riparian species • Extensive forests largely eliminated during agricultural development

• Habitat destruction is the primary problem

• The favorite oak species for ecological restoration

• Form ectomycorrhizal relationships

• Acorns provide food for many small animals and are adapted to survival in our harsh summer drought climate

• OAK APPLES caused by CYNIPID WASP (Andricuscalifornicus)

•Galls are formed when adult wasps deposit their eggs into plant tissue in the summer

• Larval secretions cause the galls to form as larvae feed within.

•When mature, the wasp chews a hole in the gall and flies off (usually in late spring)