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Rosaceae FAMILY

Crataegus opaca

Crataegus opaca

Edibility
3/5
Medicinal
2/5

Safety & Hazards

None known

Cultivation Details

HabitDeciduous Shrub
GrowthMedium

Crataegus opaca is a very hardy species, tolerating temperatures down to about -30°c[1]. A very easily grown plant, it prefers a well-drained moisture retentive loamy soil that is slightly acid, but is not at all fussy[2, 3, 4]. Once established, it succeeds in excessively moist soils and also tolerates drought[3]. It grows well on a chalk soil and also in heavy clay soils[3]. It thrives in acid soils[1, 4]. A position in full sun is best when plants are being grown for their fruit, they also succeed in semi-shade though fruit yields and quality will be lower in such a position[2, 3]. Most members of this genus succeed in exposed positions, they also tolerate atmospheric pollution[3]. Crataegus opace is occasionally cultivated for its fruit, especially in southeastern N. America[5]. There are some named varieties[6, 4]. Crataegus species often hybridize freely with other members of the genus[2, 3]. This statement is not fully accurate; at least in the wild most Crataegus species usually breed true and only occasionally hybridize - in addition, any hybrids are usually putative[7]. Many Crataegus species are very variable with regard to fruit size and quality. Seedlings, even if obtained from a good fruiting form, can often be disappointing - though they can also be an improvement on the original form. The most reliable way of obtaining a good fruiting form is by grafting from a known good tree, or obtaining a named cultivar from a reliable source[PFAF]. Seedling trees take from 5 - 8 years before they start bearing fruit, though grafted trees will often flower heavily in their third year[PFAF]. The flowers have a foetid smell somewhat like decaying fish. This attracts midges which are the main means of fertilization. When freshly open, the flowers have more pleasant scent with balsamic undertones[8]. Seedlings should not be left in a seedbed for more than 2 years without being transplanted[2].

Propagation

Seed - this is best sown as soon as it is ripe in the autumn in a cold frame, some of the seed will germinate in the spring, though most will probably take another year. Stored seed can be very slow and erratic to germinate, it should be warm stratified for 3 months at 15°c and then cold stratified for another 3 months at 4°c[9]. It may still take another 18 months to germinate[10]. Scarifying the seed before stratifying it might reduce this time[11]. Fermenting the seed for a few days in its own pulp may also speed up the germination process[PFAF]. Another possibility is to harvest the seed 'green' (as soon as the embryo has fully developed but before the seedcoat hardens) and sow it immediately in a cold frame. If timed well, it can germinate in the spring[11]. If you are only growing small quantities of plants, it is best to pot up the seedlings as soon as they are large enough to handle and grow them on in individual pots for their first year, planting them out in late spring into nursery beds or their final positions. When growing larger quantities, it might be best to sow them directly outdoors in a seedbed, but with protection from mice and other seed-eating creatures. Grow them on in the seedbed until large enough to plant out, but undercut the roots if they are to be left undisturbed for more than two years. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Crataegus+opaca>

Pollinators

Midges

References

  1. [1]Wonder Crops. 1987. — Natural Food Institute, ↩︎Fascinating reading, this is an annual publication. Some reports do seem somewhat exaggerated though.
  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]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.
  4. [4]Plants Database — United States Department of Agriculture · http://plants.usda.gov/java/factSheet ↩︎An online database with an excellent collection of fact sheets about native N. American plants.
  5. [5]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.
  6. [6]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.
  7. [7]Annals of the Missouri Botanical Garden Vol 92 — Missouri Botanical Garden; St. Louis, Missouri · 2005 · http://www.mbgpress.org · ISBN 0026-6493 ↩︎A botanical journal, containing a range of articles
  8. [8]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.
  9. [9]Growing from Seed. Volume 4. — Bird. R. (Editor) · Thompson and Morgan. · 1990 · ISBN - ↩︎Very readable magazine with lots of information on propagation. A good article on Yuccas, one on Sagebrush (Artemesia spp) and another on Chaerophyllum bulbosum.
  10. [10]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.
  11. [11]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.
  12. [12]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.
  13. [13]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.
  14. [14]Sturtevant's Edible Plants of the World. — Hedrick. U. P. · Dover Publications · 1972 · ISBN 0-486-20459-6 ↩︎Lots of entries, quite a lot of information in most entries and references.
  15. [15]Trees of North Texas — Vines. R.A. · University of Texas Press. · 1982 · ISBN 0292780206 ↩︎A readable guide to the area, it contains descriptions of the plants and their habitats with quite a bit of information on plant uses.
  16. [16]A Field Guide to Medicinal Plants. Eastern and Central N. America. — Foster. S. & Duke. J. A. · Houghton Mifflin Co. · 1990 · ISBN 0395467225 ↩︎A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
  17. [17]Hawthorns and Medlars — Phipps J.B.; O'Kennon R.J. & Lance R.W. · Timber Press; Portland · 2003 · ISBN 0-88192-591-8 ↩︎An excellent guide to some of the better known Crataegus species, plus quite a few less well-known. It also contains some information on the Medlar.
  18. [PFAF]Plants for a Future — pfaf.org ↩︎