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Rosaceae FAMILY

Rosa californica

Rosa californica

Edibility
3/5
Medicinal
2/5

Safety & Hazards

There is a layer of hairs around the seeds just beneath the flesh of the fruit. These hairs can cause irritation to the mouth and digestive tract if ingested.

Cultivation Details

HabitDeciduous Shrub
Growth—

Rosa californica is a very cold-hardy plant, being able to tolerate temperatures down to around -25°c when fully dormant[1]. Most Rosa species require a sunny position if they are to flourish and flower well. They prefer a circumneutral pH, succeeding in a range of soil texturess so long as they are moist but well-drained[2, 1]. The flowers have a rich perfume[3]. The plant that is most commonly grown as an ornamental under this name is in fact Rosa nutcana[1]. Rose species will often hybridize freely with other members of the genus[4]. Plants in this genus are notably susceptible to honey fungus[1].

Propagation

Seed. Rose seed often takes two years to germinate. This is because it may need a warm spell of weather after a cold spell in order to mature the embryo and reduce the seedcoat[4]. One possible way to reduce this time is to scarify the seed and then place it for 2 - 3 weeks in damp peat at a temperature of 27 - 32°c (by which time the seed should have imbibed). It is then kept at 3°c for the next 4 months by which time it should be starting to germinate[4]. Alternatively, it is possible that seed harvested 'green' (when it is fully developed but before it has dried on the plant) and sown immediately will germinate in the late winter. This method has not as yet(1988) been fully tested[4]. Seed sown as soon as it is ripe in a cold frame sometimes germinates in spring though it may take 18 months. Stored seed can be sown as early in the year as possible and stratified for 6 weeks at 5°c[1]. It may take 2 years to germinate[1]. Prick out the seedlings into individual pots when they are large enough to handle. Plant out in the summer if the plants are more than 25cm tall, otherwise grow on in a cold frame for the winter and plant out in late spring. Cuttings of half-ripe wood with a heel, July in a shaded frame. Overwinter the plants in the frame and plant out in late spring[5]. High percentage[5]. Cuttings of mature wood of the current seasons growth. Select pencil thick shoots in early autumn that are about 20 - 25cm long and plant them in a sheltered position outdoors or in a cold frame[5, 1]. The cuttings can take 12 months to establish but a high percentage of them normally succeed[5]. Division of suckers in the dormant season. Plant them out direct into their permanent positions. Layering. Takes 12 months[2]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Rosa+californica>

Pollinators

Insects, Self

References

  1. [1]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.
  2. [2]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.
  3. [3]Scented Flora of the World. — Genders. R. · Robert Hale. London. · 1994 · ISBN 0-7090-5440-8 ↩︎An excellent, comprehensive book on scented plants giving a few other plant uses and brief cultivation details. There are no illustrations.
  4. [4]Hardy Woody Plants from Seed. — McMillan-Browse. P. · Grower Books · 1985 · ISBN 0-901361-21-6 ↩︎Does not deal with many species but it is very comprehensive on those that it does cover. Not for casual reading.
  5. [5]Propagation of Trees, Shrubs and Conifers. — Sheat. W. G. · MacMillan and Co · 1948 · ISBN - ↩︎A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
  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]Mansfeld's Database of Agricultural and Horticultural Plants — http://mansfeld.ipk-gatersleben.de/pls/htmldb_pgrc/f?p=185:3:4292127278597336 ↩︎Terse details of a huge range of useful plants.
  8. [8]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
  9. [9]A Field Guide to N. American Edible Wild Plants. — Elias. T. and Dykeman. P. · Van Nostrand Reinhold · 1982 · ISBN 0442222009 ↩︎Very readable.
  10. [10]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.
  11. [11]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.
  12. [12]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.
  13. [13]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.
  14. [14]The New Plantsman. Volume 1, 1994. — Matthews. V. · Royal Horticultural Society · 1994 · ISBN 1352-4186 ↩︎A quarterly magazine, it has articles on Himalayacalamus hookerianus, hardy Euphorbias and an excellent article on Hippophae spp.
  15. [PFAF]Plants for a Future — pfaf.org ↩︎