This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
There are nearly forty species of shrubby Spiraeas, all beautiful when in bloom, and all easily grown in ordinary garden soil. They are raised chiefly by cuttings of the ripened wood, the sturdier kinds in the open air, the more tender ones in cold frames. Seeds may also be sown when ripe, or in spring. Two colours - white and rose - predominate, and the flowering period commences as early as March and ends about August.
Fig. 444. - Spiraea japonica A. Waterer.
Arguta, 3-4 ft., May; betulifolia (corym-bosa), 1-2 ft., June; bracteata (media rotundifolia), 5-6 ft., summer; carta, 1-2 ft., summer; cantoniensis (Reevesiana), 3-4 ft.; chamoedrifolia, 2-5 ft., with a few varieties; decumbens, trailing, 6-12 in.; discolor (arioefolia), 6-10 ft.; fissa, 6-8 ft.; gracilis, 2-3 ft.; hypericifolia, 4-6 ft., with several varieties like acuta, Besseriana, crenata, thalictroides, &c; Lindleyana, 8-12 ft.; media (confusa), 2-4 ft.; Millefolium, 4-6 ft.; prunifolia, 4-5 ft., with a pretty double-flowered variety, March; pubescens (chinensis), 2-3 ft., March; sorbifolia, 3-6 ft.; Thunbergi, 1-3 ft., March; trilobata, 1-3 ft.; Van Houttei, 5-8 ft. S Aitchisoni, with pinnate leaves and masses of white flowers, is a fine plant, not yet well known.
Bella, 3-4 ft.; bullata (crispifolia), 1-2 ft.; Douglasi, 3 ft.; japonica (callosa, Fortunei), 1-3 ft., with several varieties, including Bumal-da, and its deep-rose sub-variety "Anthony Waterer" (fig. 444); alba, white; splendens, ruberrima, etc. (this species must not be confused with the herbaceous plant popularly known under the same name. See Vol. II, p. 206.; Nobleana, 3-4 ft.; salicifolia, 3-5 ft.; tomentosa, 3 ft. Many of the above are grown in pots and forced into early bloom under glass.