Black Hawthorn - Crataegus douglasii


Identification

"Crataegus douglasii is a deciduous Tree growing to 9 m (29ft 6in). It is hardy to zone (UK) 5 and is not frost tender. It is in flower in May, and the seeds ripen in September. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Midges.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: acid, neutral and basic (alkaline) soils and can grow in very alkaline soils.
It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.
It can tolerate atmospheric pollution."[PFAF]

USDA Flower Colour: White
USDA Blooming Period: Mid-spring
USDA Fruit/Seed characteristics:

Ecological Indicator Information
A shade-tolerant/intolerant, submontane to montane, North American deciduous shrub distributed in the Pacific, Cordilleran, and Central regions. Occurs on very moist to wet, nitrogen-rich soils (Moder and Mull humus forms) within boreal. temperate, cool semiarid, and cool mesothermal climates. Sporadic in open­canopy forests on water-receiving sites, scattered in poorly forested, semi-terrestrial communities on water-collecting sites (swamps). Characteristic of nutrient-rich wetlands. [IPCBC][E-flora]


Hazards

Edible Uses

Other Uses

Medicinal Uses


Cultivation

"A very easily grown plant, it prefers a well-drained moisture retentive loamy soil but is not at all fussy[11, 200]. Once established, it succeeds in excessively moist soils and also tolerates drought[200]. It grows well on a chalk soil and also in heavy clay soils[200]. 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[11, 200]. Most members of this genus succeed in exposed positions, they also tolerate atmospheric pollution[200]. Hybridizes freely with other members of this genus[200]. Seedling trees take from 5 - 8 years before they start bearing fruit, though grafted trees will often flower heavily in their third year[K]. 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[245]. Seedlings should not be left in a seedbed for more than 2 years without being transplanted[11]." [PFAF]

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 15oc and then cold stratified for another 3 months at 4oc[164]. It may still take another 18 months to germinate[78]. Scarifying the seed before stratifying it might reduce this time[80]. Fermenting the seed for a few days in its own pulp may also speed up the germination process[K]. 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[80]. 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." [PFAF]


References


Page last modified on Thursday, January 10, 2019 1:33 AM