NOTES ON A ROCK GARDEN. 



419 



Euonymus radicans kewensis is a very charming, compact, little trailing 

 shrub; E. microphyllus, E. m. variegatus, and E. nanus variegatus are 

 very small indeed. Cotoneaster congesia and C. adpressa are most 

 useful when planted behind stones, so that they may ramble over them. 

 C. horizontalis is a larger species, and very pretty in the autumn 

 with its brightly-tinted foliage and beautiful red berries. Salix 

 reticulata, S. Myrsinites, and S. serpy Hi folia, of procumbent habit, are 

 useful in shady places where other plants will not do well. Corokia 

 Cotoneaster is a pretty, dwarf, and curious New Zealand shrub, forming 

 a dense, much-branched mass. Its leaves are small and white on the 

 underside, and the plant bears myriads of minute yellow star-shaped 

 flowers. 



Other shrubs suitable for the rock garden are Ilex crenata, Thuya 

 occidentalis Spaethii, Hedera Helix va.r. minima, Retinospor a Sanderi, and 

 Cupressus pisifera var. plumosa aurea. Colletia cruciata is a curious 

 Chilian shrub of the Buckthorn order. Its stems are armed with stout 

 flattened spines, and its white flowers, though small, are fragrant and 

 very numerous in summer. It requires a sheltered yet sunny position. 

 Hypericum (St. John's Wort) is a most useful genus for the rock 

 garden. H. olympicum, one of the largest-flowered, is 1 foot high, with 

 glaucous fol age. After flowering the plant should be cut down almost 

 to the ground, to encourage the new growth for the following season. 

 It may be increased by division, cuttings, or seeds. H. Moserianum is 

 a handsome hybrid. H. olympicum gracile and H. fragile are beauti- 

 ful plants for sunny or half-shady crevices. They cling tightly to the 

 rocks and bear a mass of yellow flowers. H. reptans should be planted 

 behind a stone, so that the foliage may grow down over the face where 

 its masses of yellow flowers show to advantage. It does best in half 

 shade and in a sheltered position, and may be increased by seed and 

 cuttings. 



Of Lithospermum two of the finest are L. prostratum and L. p. 

 ' Heavenly Blue,' spreading little evergreens, the former with flowers of 

 a lovely blue, with faint reddish- violet stripes, borne in great profusion 

 when the plant is well grown. ' Heavenly Blue,' as its name indicates, 

 is of a lighter colour. They are hardy, and valuable as rock plants by 

 reason of their prostrate habit and fine blue flowers— a blue scarcely 

 surpassed by that of the Gentians. L. p. ' Heavenly Blue ' grows best on 

 a hot sunny bank in a deep compost of sandy soil with a little peat 

 or leaf-mould ; it is easily increased by cuttings taken in August or 

 September. The cuttings, if put into a close frame or greenhouse, 

 take from six weeks to two months to root. When rooted they should 

 be potted singly, kept in frames for the winter, and planted out in 

 the spring. It should be noted that these Lithospermums will not grow 

 in soil which contains lime. L. prostratum, I find, is much more difficult 

 to root than ' Heavenly Blue.' 



Ceratostigma plumbaginoides syn. Plumbago Larpentae, a very 

 desirable Chinese plant, grows 1 foot high and bears bright cobalt-blue 

 flowers in the autumn, at which season the leaves change to a beautiful 



