IRISH GARDENING 



i53 



Hardy Stonecrops. 



By R. Lloyd Praeger, B.A. 



In the minds of some rock-gardeners I think 

 there is rather a prejudice against Sedums. No 

 douDt this arises from the fact that a few of the 

 more rampant ones, such as S. album and S. 

 rupestre, are very common in gardens. They 

 increase quickly, are difficult to keep in check, 

 since every loose scrap will take root and grow ; 

 they have in consequence got into the gardener's 

 black books by smothering some of his treasures. 

 But there are few genera which, taken as a whole, 

 are more valuable or more decorative in the rock- 

 garden, and the majority of them are modest plants 

 not venturing, at least for some years, outside 

 their allotted 

 space. Apart from 

 the profusion 

 of blossom which 

 characterises them, 

 and the handsome 

 appearance of 

 many of the species, 

 the quality which 

 renders them spec- 

 ially valuable is 

 their remarkable 

 power of resisting 

 drought, and of 

 flourishing in the 

 driest and poorest 

 of soils. They come 

 of a natural order 

 — the Crassulacece 

 — distinguished for 

 its drought-resist- 

 ing qualities, and 

 their allies, the 

 S e mp e r v i v u m s, 

 even surpass the 

 Sedums as regards 

 this power. The 

 device by which 

 they attain this 

 quality is the same 

 all through the 

 order — namely, by 

 a remarkable 

 thickening of the 

 leaves or stems, 

 coupled with the 

 development of a 

 waterproof skin, 

 which converts 

 them into veritable 

 cisterns. Take 

 some leaves of the 



common Sedum album and weigh them ; weigh 

 them again after the water which they contain 

 has been dissipated by drying, and you will find 

 that they weigh only one-tenth of what they did 

 at first. The leaves of the larger S. dendroideum 

 are more efficient still, and nineteen-twentieths 

 of their weight actually consists of water. No 

 wonder that drought does not inconvenience 

 them, with such a supply ready for an emer- 

 gency. 



The Sedums are essentially a rock-garden 

 genus, while a few of the larger species, such as 

 the valuable S. spectabile, are often grown in the 

 front of the border ; as a whole they look best and 

 grow best under rock-garden conditions. While 

 the prevailing habit is prostrate, some of them 



Photo '■!/] IP Richuidson. 



Sedum dendroideum, a native of Mexico, with yellow flowers 

 in June, growing in Mr. R. McM. Smyth's Garden at Mount 

 Henry, Dalkey, on a brick wall, and hanging down 3 J feet. 



are tall and stiff. As to colour, the flowers range 

 from white through pink to deep claret-red ; 

 many are bright yellow ; one or two are green ; 

 and one delightful species — unfortunately an 

 annual — is sky-blue. The colour of the foliage, 

 which in almost every case is evergreen, varies 

 considerably, and adds to their decorative effect ; 

 it ranges from pale to dark green ; there are various 

 effective purple hues ; many are blue-grey and 

 glaucous ; and some take on a crimson tint when 

 grown exposed. As regards time of flowering, 

 the Sedums do not begin very early, but they make 

 up for that by going on far into the autumn ; the 

 earlier species begin blossoming in June ; the 

 latest do not flower till September, and last well 

 into October. When the rush of bloom is over 

 the Sedums join the Campanulas in keeping our 



rock-gardens bright 

 during the later 

 summer months. 

 The ease with 

 which almost every 

 member of the 

 genus is propaga- 

 ted is another solid 

 point in their 

 favour. With 

 many of them, if 

 they are forgotten 

 in one's pocket for 

 a week, it really 

 does not matter ! 

 On the other 

 hand, a disadvan- 

 tage, so far as the 

 serious gardener 

 is concerned, 

 attaches to them 

 on account of the 

 confusion which 

 exists, especially 

 among nurserymen 

 as to their nomen- 

 clature. Erroneous 

 and often impos- 

 sible names figure 

 in many growers' 

 lists. The nursery- 

 men are not to 

 blame — at least no 

 more than the 

 persons who buy 

 from them and pass 

 on the false names 

 to their neighbour 

 Both seller and 

 buyer use the 

 name under which 

 the plant was 

 received, and no handy book exists by which the 

 names may be checked and corrected. In my 

 own bit of rock-garden I have or have had about 

 150 species and varieties of Sedums ; nearly 

 half were received under either erroneous names 

 or under no name at all ; and I must confess that 

 many of these remain so still. Some sections of 

 the genus are puzzling, with many closely allied 

 forms ; and to run these down from existing 

 literature is by no means easy. However, all 

 the more distinct and notable species are well 

 known and easily recognised, so to the average 

 rock-gardener these difficulties do not arise. 



In the following notes a brief summary of the 

 leading species is given, followed by a grouping 

 of species under headings to help the reader to 



