5 best fragrant white-blooming shrubs

The Winner:
Koreanspice viburnum (Viburnum carlesii) There's something magical about Koreanspice viburnum in late April or early May when its snowball-like white flower clusters open to spill their intoxicating fragrance into the air—a fragrance so heady it can be enjoyed from 10 metres away. This shrub (as tall as it is wide at 1.25 to 2.5 metres) blooms for 10 days as its foliage emerges (if not deadheaded, the resulting sparse red fruit will ripen to black). Its dark green leaves have a satin-like lustre on their upper surfaces, while their undersides are fuzzy. Although their reddish fall colour is unreliable, the leaves persist into late autumn. ‘Compactum' is the dwarf form, which reaches just one metre tall and wide, and is a great choice for smaller gardens. Both prefer moderately fertile, well-drained soil and part to full sun. Zone 4.

Honourable Mentions:
Summersweet, Clethra alnifolia
Height 1.25 to 2 m; Spread 1.25 to 2 m; Location - full shade to full sun; moderately fertile, well-drained to moist soil; Cultivation - spreads by stolons; Flowers - white, fragrant, five-petalled, upright panicles; blooms last up to six weeks and attract bees; July to August; Foliage - lustrous dark green in summer; pale yellow to yellow-brown in fall; Zone 4

‘Henry Hudson' hybrid rugosa shrub Explorer rose Rosa ‘Henry Hudson'
Height 75 cm; Spread 30 to 45 cm; Location - part to full sun; moderately fertile, well-drained soil; Cultivation - deadhead if desired; disease-resistant; Flowers - crimson-flushed buds open to very fragrant, semi-double, pinkish white flowers; recurrent blooms until frost; Foliage - deep green; Fruit - abundant bright red hips in fall; Zone 3

‘Carol Mackie' burkwood daphne Daphne x burkwoodii ‘Carol Mackie'
Height 1.25 m; Spread 1.5 m; Location - part to full sun; moderately fertile, well-drained soil with neutral pH; Cultivation - mulch 2.5 cm deep with leaf mould, compost or small bark chips; Flowers - small, star-shaped, pink-tinged buds in clusters opening white; very fragrant; May; Foliage - evergreen; greyish green with narrow, yellow margins; Zone 4

Also consider these plants:
‘Blizzard' mock orange
Philadelphus lewisii ‘Blizzard', Zone 3