The correct popular name for these easily grown shrubs is mock orange from the resemblance in appearance and scent of theof some varieties to orange blossom. It is a pity that they are sometimes called , the botanical name of , a totally unrelated shrub.
All the popular varieties of philadelphus are completely hardy and will grow in all reasonably fertile soils preferably in a sunny, or at least light, and openwhere they flower most freely. All flower in June and nearly all are white, though often with some suffusion of purple and with yellow stamens which show clearly in the single-flowered varieties. Varieties differ greatly in size and habit, a few reaching a height of 10 or 12 ft., but all can be reduced in size by out the old flowering as soon as the fade. The young, non-flowering stems should be retained to flower the following year.
Good varieties are Beauclerk, ivory white and purple, 7 ft. ; Belle Etoile, white and purple, 6 ft. ; coronarius, creamy white, 6 ft., and its variety aureus, not very free flowering but with yellow foliage; delavayi, white and purple, 10 ft. ; Manteau d’Hermine, creamy white, double, 3 ft.; microphyllus, white, small flowers and, 3 ft. ; Sybille, white and purple, 4 ft. ; Virginal, white, double, 8 ft.
Philadelphus hybrids comprise various crosses which flower in June-July, including ‘Beauclerk’, a branching shrub up to 2 m tall and broad, with fragrant white flowers up to 7 cm across, with folded-back petals which are pink at the base; ‘Belle Etoile’, a vigorous shrub with white flowers, 4.5 cm across, with a purplish-red ring in the heart surrounding yellow stamens; ‘Limonel’ is less bushy and up to 2 m tall with fragrant, white flowers; ‘Manteau d’Hermine’, 75-100 cm tall and broad, with double, snowy-white flowers, approx. 4 cm across; ‘Silberregen’ (syn. ‘Silver Showers’) is less bushy and up to 1 m tall and broad with fragrant, double, white flowers, ‘Virginal’ is a vigorous, upright shrub, 2-3 m tall, with beautifully fragrant, double, white flowers, 4-5 cm across.