
Hydrangea aspera
Hydrangea aspera
Safety & Hazards
There is a report that the fresh plant contains the toxin hydrogen cyanide[1]. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.
Cultivation Details
Succeeds in most good soils, including chalk[2].This species is one of the most chalk-tolerant members of the genus[3]. Tolerates most soils[3], thriving in a well-drained loamy soil[4], but resenting dryness at the roots[5, 3]. Succeeds in full sun or semi-shade[3], but if it is grown in a low rainfall area then it requires shade at the hottest part of the day[5]. Does well on very acid soils with a pH around 4.5[3]. The colour of the flowers reflects the pH of the soil the plant is growing in, the flowers are pink in a neutral to alkaline soil and blue in an acid soil. Grows well in an open woodland garden[3]. Although fairly tolerant of soil type, this species is not very easy to grow well, it is best given a dryish soil, it resents winter wet[5]. Dormant plants are hardy to about -15°c[2]. They are somewhat tender when young, and the young growth of older plants is also susceptible to damage by late frosts[5]. Plants resent being pruned[6]. This species is notably susceptible to honey fungus[3].
Propagation
Seed - surface sow in a greenhouse in spring[7]. Cover the pot with paper until the seed germinates[8]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Cuttings of half-ripe wood, 8cm long, mid summer in a frame. Overwinter in a greenhouse and plant out in late spring[8]. Cuttings of mature wood in late autumn in a frame[3]. Mound layering in spring. Takes 12 months[8]. Leaf-bud cuttings of the current seasons growth in a frame[3]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Hydrangea+aspera>
Pollinators
Data unavailable
References
- [1]Medicinal Plants of Nepal — Dept. of Medicinal Plants. Nepal. · 1993 · ISBN - ↩︎Terse details of the medicinal properties of Nepalese plants, including cultivated species and a few imported herbs.
- [2]Shrubs. — Phillips. R. & Rix. M. · Pan Books · 1989 · ISBN 0-330-30258-2 ↩︎Excellent photographs and a terse description of 1,900 species and cultivars.
- [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]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [5]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.
- [6]Climbers and Wall Shrubs. — Davis. B. · Viking. · 1990 · ISBN 0-670-82929-3 ↩︎Contains information on 2,000 species and cultivars, giving details of cultivation requirements. The text is terse but informative.
- [7]The Reference Manual of Woody Plant Propagation. — Dirr. M. A. and Heuser. M. W. · Athens Ga. Varsity Press · 1987 · ISBN 0942375009 ↩︎A very detailed book on propagating trees. Not for the casual reader.
- [8]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.
- [9]Flowers of the Himalayas. — Polunin. O. and Stainton. A. · Oxford Universtiy Press · 1984 · ISBN - ↩︎A very readable and good pocket guide (if you have a very large pocket!) to many of the wild plants in the Himalayas. Gives many examples of plant uses.
- [10]Flora of China — Missouri Botanical Garden Press; St. Louis. · 1994 · http://flora.huh.harvard.edu/china/ ↩︎An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
- [11]Plants for Human Consumption. — Kunkel. G. · Koeltz Scientific Books · 1984 · ISBN 3874292169 ↩︎An excellent book for the dedicated. A comprehensive listing of Latin names with a brief list of edible parts.
- [12]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.