NOTES ON A ROCK GARDEN. 



421 



Linnaea borealis and L. b. americana are rare plants in gardens, with 

 pretty leaves, and slender stems bearing pairs of dainty, fragrant, rosy 

 flowers. They do best in a shady place on the side of a bog-garden 

 in peat, loam, and sand, or on the north of the rockery, near a path, 

 where they can have attention. A top dressing of leaf-mould and sand 

 should be given once or twice a year, so that they may root freely. 

 Pegging down should be attended to, in case the wind loosens the 

 shoots. A rather damp bottom suits it well. 



Andro>aces are typical alpines, of fascinating beauty, but many of 

 them are difficult to grow. Their worst enemies are winter and early 

 spring rains. They require a rich sandy or gritty loam, with a liberal 

 mixture of small lumps of sandstone. Full exposure to the sun suits 

 them well, and though their silky roots find a difficulty in penetrating 

 stiff, sticky soil, they will search deeply into light, gritty loam, on a slope, 

 finding the moisture which they love among the buried stones, and so 

 withstand and enjoy a scorching sun, which in a stiff er soil would kill 

 them outright. A covering of a sheet of glass is of the greatest help 

 to the woolly species in winter. Androsace arachnoidea, A . sarmentosa, 

 A. s. Chumbyi, A. primtdoides , and A. sempervivoides all require similar 

 treatment, and should be planted on a sloping bed, facing full sun, a 

 rock sheltering them from the north-east. They require a little lime- 

 stone or mortar rubble added to soil. These Andiosaces throw out 

 numerous runners like those of a strawberry. These may be pegged 

 down, or cut off and potted, to increase stock. All these Andro- 

 saces bear flowers similar to those of Primula, varying in colour 

 from deep pink to white, with various-coloured centres. Androsace 

 lanuginosa, a Himalayan species, has trailing stems, silky foliage, and 

 bears in September heads of rose-pink, yellow-eyed flowers. It should be 

 planted so that it hangs over a stone in a well-drained, sunny position. 

 The compost should be of gritty loam and peat, with a little limestone. 

 The plant should be cut back in the spring, and is easily increased by 

 cuttings made in September. A . lanuginosa Leichtlinii is similar to the 

 last named, and requires similar treatment ; but it flowers more freely, 

 and has white flowers with carmine eyes. A . foliosa is a distinct species 

 with long, narrow leaves and lilac-pink flowers. It is a robust grower, 

 flowers freely late into the autumn, and requires a well-drained position, 

 facing full south. It should be planted in a crevice, in a compost of good 

 gritty loam and limestone. A. Laggeri will grow best in a position 

 where it is shaded from the midday sun, and should be planted in 

 good, deep, gritty, peaty soil, top-dressed in the spring and autumn. 

 It may be increased by seeds and division. A. glacialis, a plant from 

 the high Alps, with lilac flowers, is quite at home in the moraine garden, 

 but may be grown in a compost of gritty loam, leaf-mould, and peat in 

 equal parts. It should be top-dressed in spring and autumn, and 

 increased by division and seeds. Douglasia Vitaliana, from the Pyrenees, 

 is a choice alpine of compact habit, with golden-yellow flowers. Its 

 requirements are similar to those of A. glacialis. A. carnea and c. alba 

 are both of very easy growth, especially as their leaves are not woolly, 



