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Fagaceae FAMILY

Notholithocarpus densiflorus

Notholithocarpus densiflorus

Edibility
2/5
Medicinal
2/5

Safety & Hazards

The tree's leaf and twig trichomes shed when disturbed. They irritate the skin and are easily inhaled, making it unpleasant to log in tanoak forests[1].

Cultivation Details

HabitEvergreen Tree
GrowthSlow

Notholithocarpus densiflorus is a moderately cold-hardy tree, tolerating occasional temperatures down to around -15°c when dormant. It grows best in areas with to a mediterranean climate modified by cool-moist coastal air currents. It grows in a region where the mean annual precipitation ranges from 1,020 - 2,540mm, with rainy winters and dry summers and autumns. Productive tanoak sites are humid, with plentiful moisture from soil, rain, fog, low clouds, and/or high humidity. Both young and older trees are shade tolerant; they also grow well in full sun[1]. Prefers a deep fertile soil with medium drainage[2], growing in the wild on a variety of soil types[3, 4]. A slow-growing tree in the wild, living up to 300 - 350 years old[4]. Plants usually flower in the spring and sometimes again in the autumn[5]. The seeds take two seasons to ripen[4]. Prolific crops are usually produced every other year in the wild[4]. The mean annual production of trees with boles between 45 - 60cm in diameter is estimated at 3,900 - 4,600 acorns. A 24-year study on a productive northern California site found tanoak seed production was more consistent than that of associated California black oaks (Quercus kelloggii) and Pacific madrones. Tanoak production was mostly light. Tanoak acorn production in a heavy seed year ranged from 220,000 - 420,000 sound acorns per hectare[1]. Tanoak seedlings quickly develop a burl at the base of the trunk from which they can resprout if damaged. The burl is already partly effective within a few days of germination and is fully developed within about 5 years[1]. Young plants often die back to this burl for no apparent reason. The original seedling stem typically dies back by the time the plant is 6 - 12 years old, with the new stem being somewhat stouter stem than the original. The tree can die back and resprout from the burl at least 3 to 5 times by the age of 60, even when top-killing events are not apparent. The burl buds divide as the burl enlarges, so the number of subsurface buds increases as tanoaks age. One large tanoak stump supported about 1,400 buds. Open-grown tanoaks tend to produce more sprouts/burl than tanoaks in shade. The sprouts can be very dense after logging or fire, often forming extensive stands[1].

Propagation

The seed is best sown as soon as it is ripe in the autumn in a cold frame[2]. It needs to be protected from mice, squirrels and other seed eaters. The seed has a short viability but can be stored for a few months if kept cool and slightly damp - the salad compartment of a fridge is a good storage place. Germination takes place in the winter or early spring. When they are large enough to handle, prick the seedlings out into individual pots. If the plants are 15cm or more tall by the summer they can be planted out into their permanent positions. Give them a good weed-excluding mulch and some protection from the cold for their first couple of years outdoors. If growth is not sufficient then grow them on in the greenhouse for their first winter and plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Notholithocarpus+densiflorus>

Pollinators

Data unavailable

References

  1. [1]Fire Effects Information System — http://www.feis-crs.org/feis/ ↩︎An on-line information site with comprehensive information on over 1,100 species of plant. Mainly developed to supply information on the effects of fire on plants and animals, it also contains a wealth of other information on the plants
  2. [2]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  3. [3]Manual of the Trees of N. America. — Sargent. C. S. · Dover Publications Inc. New York. · 1965 · http://www.biodiversitylibrary.org/ · ISBN 0-486-20278-X ↩︎Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. It can be downloaded from the internet.
  4. [4]The Complete Trees of N. America. Field Guide and Natural History. — Elias. T. · Van Nostrand Reinhold Co. · 1980 · ISBN 0442238622 ↩︎A very good concise guide. Gives habitats, good descriptions, maps showing distribution and a few of the uses. It also includes the many shrubs that occasionally reach tree proportions.
  5. [5]The RHS Gardener's Encyclopedia of Plants and Flowers — Brickell. C. · Dorling Kindersley Publishers Ltd. · 1990 · ISBN 0-86318-386-7 ↩︎Excellent range of photographs, some cultivation details but very little information on plant uses.
  6. [6]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
  7. [7]A California Flora. — Munz P.A. & Keck D.D. · University of California Press; Los Angeles · 1959 · ISBN - ↩︎An excellent flora but no pictures. Not for the casual reader.
  8. [8]Common Edible and Useful Plants of the West. — Sweet. M. · Naturegraph Co. · 1962 · ISBN 0-911010-54-8 ↩︎Useful wild plants in Western N. America. A pocket guide.
  9. [9]Edible and Useful Wild Plants of the United States and Canada. — Saunders. C. F. · Dover Publications · 1976 · ISBN 0-486-23310-3 ↩︎Useful wild plants of America. A pocket guide.
  10. [10]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
  11. [11]Cornucopia - A Source Book of Edible Plants. — Facciola. S. · Kampong Publications · 1990 · ISBN 0-9628087-0-9 ↩︎Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
  12. [12]Food Plants of the N. American Indians. — Yanovsky. E. · U.S. Depf of Agriculture. · ISBN - ↩︎A comprehensive but very terse guide. Not for the casual reader.
  13. [13]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
  14. [14]Encyclopaedia Britannica. 15th edition. — ? ↩︎It contains a few things of interest to the plant project.
  15. [15]Economic Botany. — Hill. A. F. · The Maple Press · 1952 · ISBN - ↩︎Not very comprehensive, but it is quite readable and goes into some detail about the plants it does cover.
  16. [PFAF]Plants for a Future — pfaf.org ↩︎