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Juglans californica
  • California Walnut

a perennial woody deciduous member of the Juglans genus in the family Juglandaceae.

Niche
  • Canopy
    Canopy
    There are no details available for this niche.
Functions
  • Rootstock
    Rootstock
    There are no details available for this function.
Light
  • Full sun
    Full sun
    The amount of sun exposure that a plant prefers in ideal conditions.
    Key
  • no shade
    No shade
    The amount of shade a plant will tolerate without adverse health affects.
    Key
Water
  • Water Requirementsmoderate
    Moderate
    The amount of water a plant needs for healthy growth, relative to other plants.
    Key
Soil
  • acid,neutral,alkaline
    Acid to Alkaline
    The PH range (acidity or alkilinity) of the growth medium ideal for healthy nutrient absorbtion.
    Key
  • Sandy to Clay
    The soil texture this plant prefers for optimal growth.
    Key
Cold & Heat
  • 8
    Zone 8
    The USDA Hardiness scale assigns plants a number from 1 to 12 representing the minimum temperature a plant can survive.
    Key
    0< -53.9ºC< -65ºF
    1-51.1ºC-60ºF
    2-45.6ºC-50F
    3-40ºC-40ºF
    4-34.4ºC-30ºF
    5-28.9ºC-20ºF
    6-23.3ºC-10ºF
    7-17.8ºC0ºF
    8-12.2C10ºF
    9-6.7ºC20ºF
    10-1.1ºC30ºF
    114.4ºC40ºF
    12> 10ºC> 5ºF
  • ?
    Unknown
    The AHS Heat scale assigns plants a number from 1 to 12 representing the number of days per year a plant requires a temperature exceeding 30ºC (86ºF).
    Key
    11
    21 - 7
    38 - 14
    415 - 30
    531 - 45
    646 - 60
    761 - 90
    891 - 120
    9121 - 150
    10151 - 180
    11181 - 210
    12181 - 210
Juglans californica has 0 edible uses listed
Juglans californica has 0 material uses listed
Juglans californica has 0 medicinal uses listed

Uses

Edible uses

Notes

Seed - raw, cooked or used in pies, confections etc[1]. A sweet flavour[2]. The seed is small with a thick shell but it makes good eating[1]. The seed is up to 15mm in diameter[2]. An edible oil is obtained from the seed, it tends to go rancid quickly.

Unknown part

Oil

Seed

Unknown use

Material uses

Often used as a rootstock for J. regia.

Plants produce chemicals which can inhibit the growth of other plants. These chemicals are dissolved out of the leaves when it rains and are washed down to the ground below, reducing the growth of plants under the tree[3][4][5]. The roots of many members of this genus produce substances that are toxic to many plant species, especially apples (Malus species), members of the Ericaceae, Potentilla spp and the white pines (certain Pinus spp.)[6].

Wood - moderately coarse-grained. An attractive wood, but the frequent branching pattern of the trunk limits the use of this wood commercially[2]

Unknown part

Herbicide
Wood

Medicinal uses(Warning!)

An infusion of the leaves is used to treat thin blood[7].

Unknown part

Blood tonic

Ecology

Ecosystem niche/layer

Canopy

Ecological Functions

Rootstock

Forage

Nothing listed.

Shelter

Nothing listed.

Propagation

The seed is best sown as soon as it is ripe in individual deep pots in a cold frame[8]. You need to protect it from mice, birds, squirrels etc. The seed usually germinates in late winter or the spring. Plant out the seedlings into their permanent positions in early summer and give some protection from the cold for their first winter or two. The seed can also be stored in cool moist conditions (such s the salad compartment of a fridge) over the winter and sown in early spring but it may then require a period of cold stratification before it will germinate[9][8].

Practical Plants is currently lacking information on propagation instructions of Juglans californica. Help us fill in the blanks! Edit this page to add your knowledge.



Cultivation

Requires a deep well-drained loam and a sunny position sheltered from strong winds[10][11]. Prefers a slightly alkaline soil[6].

Plants are not very hardy in Britain, tolerating temperatures down to between -5 and -10°c[6]. A fairly fast-growing tree in its native habitat, but quite short-lived, dying after about 125 - 150 years[2]. Plants produce a deep taproot and they are intolerant of root disturbance[10][11]. Seedlings should be planted out into their permanent positions as soon as possible and given some protection since they are somewhat tender when young[10][11]. Flower initiation depends upon suitable conditions in the previous summer[6]. The flowers and young growths can be destroyed by even short periods down to -2°c, but fortunately plants are usually late coming into leaf[6]. Any pruning should only be carried out in late summer to early autumn or when the plant is fully dormant otherwise wounds will bleed profusely and this will severely weaken the tree[6]. Trees have a dense canopy which tends to reduce plant growth below them. We have no specific information for this species, but the roots of several members of this genus produce substances that are toxic to many plant species, especially apples (Malus species), members of the Ericaceae, Potentilla spp and the white pines (certain Pinus spp.)[6]. The leaves of many species also secrete substances that have an inhibitory affect on plants growing underneath them. All in all this is not a very good companion plant[K].

Closely related to J. hindsii[1][6]

Crops

Problems, pests & diseases

Associations & Interactions

There are no interactions listed for Juglans californica. Do you know of an interaction that should be listed here? edit this page to add it.

Polycultures & Guilds

There are no polycultures listed which include Juglans californica.

Descendants

Cultivars

Varieties

None listed.

Subspecies

None listed.

Full Data

This table shows all the data stored for this plant.

Taxonomy
Binomial name
Juglans californica
Genus
Juglans
Family
Juglandaceae
Imported References
Edible uses
[1][2]
Medicinal uses
[7]
Material uses & Functions
[3][4][5][6][2]
Botanic
[11][12][6]
Propagation
Cultivation
Environment
Cultivation
Uses
Edible uses
None listed.
Material uses
None listed.
Medicinal uses
None listed.
Functions & Nature
Functions
Rootstock
Provides forage for
Provides shelter for
Environment
Hardiness Zone
8
Heat Zone
?
Water
moderate
Sun
full sun
Shade
no shade
Soil PH
acid, neutral, alkaline
Soil Texture
sandy, loamy, clay
Soil Water Retention
well drained
Environmental Tolerances
    Ecosystems
    Native Climate Zones
    None listed.
    Adapted Climate Zones
    None listed.
    Native Geographical Range
    None listed.
    Native Environment
    None listed.
    Ecosystem Niche
    Canopy
    Root Zone Tendancy
    None listed.
    Life
    Deciduous or Evergreen
    deciduous
    Herbaceous or Woody
    woody
    Life Cycle
    perennial
    Growth Rate
    moderate
    Mature Size
    x meters
    Fertility
    self fertile
    Pollinators
    Wind
    Flower Colour
    ?
    Flower Type
    monoecious











    References

    1. ? 1.01.11.21.3 Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications ISBN 0-9628087-0-9 (1990-00-00)
    2. ? 2.02.12.22.32.42.5 Elias. T. The Complete Trees of N. America. Field Guide and Natural History. Van Nostrand Reinhold Co. ISBN 0442238622 (1980-00-00)
    3. ? 3.03.1 Philbrick H. and Gregg R. B. Companion Plants. Watkins (1979-00-00)
    4. ? 4.04.1 Riotte. L. Companion Planting for Successful Gardening. Garden Way, Vermont, USA. ISBN 0-88266-064-0 (1978-00-00)
    5. ? 5.05.1 McPherson. A. and S. Wild Food Plants of Indiana. Indiana University Press ISBN 0-253-28925-4 (1977-00-00)
    6. ? 6.06.16.26.36.46.56.66.76.86.9 Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press ISBN 0-333-47494-5 (1992-00-00)
    7. ? 7.07.1 Moerman. D. Native American Ethnobotany Timber Press. Oregon. ISBN 0-88192-453-9 (1998-00-00)
    8. ? 8.08.1 McMillan-Browse. P. Hardy Woody Plants from Seed. Grower Books ISBN 0-901361-21-6 (1985-00-00)
    9. ? Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co (1948-00-00)
    10. ? 10.010.110.2 F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press (1951-00-00)
    11. ? 11.011.111.211.3 Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray (1981-00-00)
    12. ? Munz. A California Flora. University of California Press (1959-00-00)


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    Facts about "Juglans californica"RDF feed
    Article is incompleteYes +
    Article requires citationsNo +
    Article requires cleanupYes +
    Belongs to familyJuglandaceae +
    Belongs to genusJuglans +
    Functions asRootstock +
    Has binomial nameJuglans californica +
    Has common nameCalifornia Walnut +
    Has drought toleranceIntolerant +
    Has edible partUnknown part + and Seed +
    Has edible useOil + and Unknown use +
    Has fertility typeSelf fertile + and Wind +
    Has flowers of typeMonoecious +
    Has growth rateModerate +
    Has hardiness zone8 +
    Has lifecycle typePerennial +
    Has material partUnknown part +
    Has material useHerbicide + and Wood +
    Has medicinal partUnknown part +
    Has medicinal useBlood tonic +
    Has search namejuglans californica + and california walnut +
    Has shade toleranceNo shade +
    Has soil ph preferenceAcid +, Neutral + and Alkaline +
    Has soil texture preferenceSandy +, Loamy + and Clay +
    Has soil water retention preferenceWell drained +
    Has sun preferenceFull sun +
    Has taxonomic rankSpecies +
    Has taxonomy nameJuglans californica +
    Has water requirementsmoderate +
    Inhabits ecosystem nicheCanopy +
    Is deciduous or evergreenDeciduous +
    Is herbaceous or woodyWoody +
    Is taxonomy typeSpecies +
    PFAF cultivation notes migratedNo +
    PFAF edible use notes migratedNo +
    PFAF material use notes migratedNo +
    PFAF medicinal use notes migratedNo +
    PFAF propagation notes migratedNo +
    PFAF toxicity notes migratedYes +
    Tolerates nutritionally poor soilNo +
    Uses mature size measurement unitMeters +
    Has subobjectThis property is a special property in this wiki.Juglans californica +, Juglans californica +, Juglans californica +, Juglans californica + and Juglans californica +