SPIR.EA 525 



by means of cuttings made of moderately firm wood placed in light sandy 

 soil in gentle bottom heat in July and August. If this be not available, 

 cuttings made of harder wood in September may be placed under bell- 

 glasses out-of-doors in a sheltered spot. For the pinnate-leaved ones 

 root-cuttings may be used. 



The Spiraeas produce fertile seed in abundance, but they cross-breed 

 with such facility that seed can only be depended on to come true when 

 the plants are fairly isolated from other species. Some of the very best 

 Spiraeas are hybrids, as may be gathered from the following descriptive notes, 

 but they have become so numerous that they make the genus, as represented 

 in gardens, excessively difficult to study and classify. Mr Zabel of Miinden 

 has devoted a volume of one hundred and twenty-eight pages exclusively 

 to ther elucidation, but many are so similar to each other that their differ- 

 entiation on paper is no longer possible within convenient limits. 



PRUNING. Few shrubs repay careful pruning better than the Spiraeas, 

 and in this matter they may be divided into two groups, viz., (i) those that 

 flower early and from the buds of shoots made the previous year, such as 

 arguta, hypericifolia, Thunbergi, Van Houttei, Veitchii, etc.; and (2) those 

 that flower later in the year at the ends of the shoots of the current 

 season, such as japonica, Douglasii, salicifolia, Lindleyana, etc. This 

 matter is fully discussed in the introductory chapter on pruning, and 

 from what is there stated it will be evident that the first group must only 

 be pruned by thinning out the older and weaker wood ; any shortening 

 back of the shoots must mean a reduction in the next crop of blossom. 

 The second group, on the other hand, is benefited by the shoots being 

 shortened back. This should, of course, be done in late winter or early 

 spring, and at the same time superfluous old shoots should be cut clean 

 out. Unless pruning of either kind is done, many of the Spiraeas get into 

 a weedy, thin condition, and their blossoms will not bear comparison 

 either in quantity or quality with that of properly pruned plants. 



The group including Douglasii, tomentosa, salicifolia, Menziesii, and 

 their hybrids form dense thickets, and spread rapidly by means of under- 

 ground suckers. These should be pruned as in group 2 (being late 

 flowering), and it is also advisable at intervals of a few years to dig them 

 up, divide 1 them into smaller pieces, and after enriching the ground, 

 replant them more thinly. This, of course, applies to ordinary cultivated 

 shrubberies and borders, but they also make admirable masses, for the 

 wilder portions of the demesne, where they can safely be left to take 

 care of themselves. In such places the reddish or rich brown stems 

 of many Spiraeas make a cheerful feature in winter. 



So many of the Spiraeas are of similar aspect and valuje, that for 

 gardens a selection suffices. The following twenty kinds may be recom- 

 mended, or, for smaller gardens, the ten marked * : 



*Arguta. 

 *Aitchisoni. 



Brachybotrys. 



Bracteata. 



Canescens 



Douglasii. 



Henryi. 

 * Japonica and its varieties. 



Media. 

 *Margaritae. 



*Prunifolia fl. pi. 



Salicifolia var. paniculata. 



Thunbergi. 



Trilobata. 

 *Van Houttei. 



*Discolor. ! *Menziesii var. triumphans. i *Veitchii. 



For the rock garden *bullala and decumbens are very suitable. 



