IRISH GARDENING. 



February 



Dwarf Shrubs for Rock Gardens 



By J. \V. Besant, Botanic Gardens, Glasnevin. 



THE number of shrubby plants suitable 

 for rock g-ardens has increased so 

 much of late years that it is no un- 

 common occurrence to find rockeries almost 

 wholly furnished with shrubs. Such a feature 

 lends considerable interest to a garden, and 

 will doubtless become more extended as the 

 difficulty of accommodating sub-shrubby and 

 herbaceous alpines becomes more acute. If we 

 consider alpine plants, as the term is popularly 

 applied, a very considerable number might be 

 strictly classed as shrubs ; such, for instance, as 

 Aethionemas, Iberises, &c. , which have short, 

 woody shoots, and may even attain a fair 

 height, as in established healthy plants of Ibcf-i's 

 sempervirens. 



The shrubs mentioned in the following notes 

 reveal what, in the present instance, is meant 

 by the title. 



Due care must be exercised when, planting 

 shrubs on the rock garden, otherwise there may 

 be troublesome pruning back or lifting to do in 

 future years. Unless on very large schemes of 

 rock-work it is not advisable to introduce 

 strong growing flowering shrubs, however 

 beautiful they may be, otherwise something 

 must suflfer. This does not preclude the use of 

 such plants about the approaches to the rock 

 garden, leading on to it, as it were ; there thev 

 ma)' be eminently suitable. 



A considerable number of shrubs not exactly 

 alpines naturally, manj- indeed garden varieties, 

 have been found to harmonise perfectly with the 

 other occupants of the artificial rock garden 

 because of their prostrate or compact habit. 



Several species of berberis will be found suitable for the 

 purpose under notice. Berberis empetrifulia, from Chili, 

 and the new B. Wilsonre, from China, are both neat 

 growing dwarf plants, the latter particularly good in 

 autumn, when the leaves turn bright-red and yellow ; 

 B. concinna, from the Himalayas, will also be found 

 useful and pleasing. Other good sorts for this purpose 

 are B. stenophylla reflexa, B. stenophylla Iriviitii, and 

 B. Thunbergii, the latter well known for the brilliant 

 colouring of the leaves in autumn. Cornus Hessei, a 

 slow-growing compact species, with dusky purplish 

 leaves, accompanied by bluish white berries in autumn, 

 may be found useful, but should be given a site where 

 there is no possibility of the soil becoming dry. The 

 cotoneasters offer some useful and pretty sorts, and 

 usualh" succeed in any position. C. adpressa is an 

 extremely interesting and beautiful species for a pro- 

 minent position ; planted where it can throw its branches 



over a friendly boulder this species will flourish and 

 furnish a feast of colour in autumn when the leaves 

 colour red and gold before falling. C. buxifolia, although 

 it will ultimately attain a considerable size in a bed, is 

 of comparativeh- slow growth, and will not soon become 

 aggressive in the rock garden ; it is nearly evergreen, 

 and produces quantities of dull red berries in autumn 

 and winter. C. microphylla and the smaller-leaved 

 variety, C. microphylla glacialis (the latter often called 

 C. cungesta), are both useful and pretty rock shrubs. 

 C. rotundifulia bears some resemblance to C. buxifolia^ 

 but has rounder leaves, and the berries are bright red 

 and highly ornamental. 



Of the broom family there are quite a number oi 

 suitable sorts, interesting at all times, and particularl\' 

 beautiful in flower. Cyfisus Ardoini, a charming \*elIow- 

 flowered sort from the Maritime -Alps, is essentially a 

 rock garden plant, and so also is the rare and beautiful 

 C. Beani, raised at Kew. C. decumbens^ of prostrate 

 habit, and bearing yellow flowers, is likewise of great 

 value, while a well grown plant of C. keivensis^ with its 

 diffuse spreading branches thickly clad with cream- 

 coloured flowers, is hardly surpassed in beauty by any 

 flowering shrub. Other good Cytisuses are C. purpureus 

 and its variety alba^ some new forms of C. scoparius 

 and C. versicolor, with small yellowish white flowers 

 tinged with pink. 



Several of the dwarf evergreen Euonymuses will be 

 found extremely useful, particularly for shady places near 

 trees. E. radicans is a prime favourite for such a 

 position, and affords some really fine varieties, such as 

 E. rad. Joliis pictis, E. rad. Silver Gem, the latter 

 particularly bright and pleasing in winter. E. rndicans 

 Carrieri is of more robust habit, and does not trail in 

 quite the same manner as the type plant, but is not less 

 useful, bearing as it does quantities of fruits in autumn, 

 which, on bursting, display the prett}' orange-coloured 

 covering of the seeds. E. minus, with narrow, bronzy 

 green leaves, may be used as well as E. japunicus, and 

 several of its beautiful silver and gold variegated 

 varieties, one of which, E. jap. versicolor, a silver form, 

 is ver}' pleasing. Fabiana imbricata, a heath-like plant 

 of the solanum family, may be used in a sheltered spot. 

 The flowers are pure white, tubular, and produced on 

 the upper portion of the branches. 



The Genistas, another genus of the pea familj', are 

 very similar to the Cytisuses in general appearance. 

 G. anglica, a spiny loose habited plant, bearing spikes 

 of yellow flowers, is useful for a dryish, sunny position, 

 as also is G. germanica, of more compact and leafy 

 growth than the former. G.pilosa is extremely floriferous, 

 and forms a spreading mass two feet high. G.saggitalis 

 affords variety ; it produces somewhat flat branches, or 

 rather shoots, of herbaceous nature and small leaves, but 

 is not so useful for the rock garden as some other 

 species. Genista iinctoria fl. pi. grows from six inches 

 to nine inches high, and is one of the finest of all dwarf 

 flowering shrubs, producing annually enormous quantities 

 of its double yellow flowers. 



Hypericums afford some useful plants for rock gardens 

 in addition to the low growing forms such as H. coris, 

 H. fragile, H. repens, &c. , generally recognised as sub- 

 jects for the rock garden. H. moserianum may be used 

 effectively. The flowers are large, waxy yellow, their 



