At this stage I am not committing to a layout but just gathering the potential plants together, please speak up if you think there are any others I should consider:
Snowdrop anemone, or windflower (Anemone sylvestris), produces a myriad of nodding flowers on 30 to 38 cm (12-15 in.) stems in early spring, with a few more flowers in fall. The plants self-seed and spread by rhizomes, so they will need some control in formal settings but are excellent when allowed to naturalize in a less formal setting. They perform equally well in sun or shade.
Babysbreath (Gypsophila paniculata) has been declared a noxious weed in Manitoba and has become quite invasive of pasture land in parts of Saskatchewan. Dwarf babysbreath (Gypsophila repens) presents no threat as it is non-invasive. It has a spreading, prostrate form and dainty white flowers above 45 cm (18 in.), mound-like foliage. It blooms in mid-summer and does best when planted in full sun in well drained soil.
Balloonflower (Playtcodon gradiflorum), which is related to the bellflowers, has a white form called ‘Album’ which grows to 60 cm and produces bell-shaped flower in July. Plants do well in full sun or partial shade.Bellflowers (Campanula spp.) form a large group which includes many white forms. ‘White Clips’ is a white-flowering bellflower (C. carpatica) which grows to 30 cm (12 in.). It flowers through most of June and July and will surprise you with seedlings. A white form of the creeping bellflower (C. cochleariifolia) is only 10 cm (4 in.) high and spreads slowly to form a mat. The peachleaf bellflower (C. persicifolia) has a white form of 75 cm (2.5 ft) which blooms in June and July.Bleeding heart (Dicentra spectabilis) - I planted some at the Ontario cottage, I much prefer them to the usual pink, has a white form called ‘Alba’ which is 60 to 90 cm (2-3 ft) high with finely divided foliage. They thrive where provided partial shade, an organic soil, and even moisture.Chrysanthemum ‘Morden Cameo’ (Chrysanthemum morifolium) is a white-flowered mom of 60 cm (2 ft) that flowers from August until hard frost. Mums prefer full sun and even moisture, and may not be fully hardy in all areas of the prairies.Ground clematis (Clematis recta) is a herbaceous clematis with slightly fragrant white flowers borne in late summer. It is a sprawler rather than a true climber and is most attractive when provided with a low support over which it can drape.Columbine (Aquilegia spp.) is available in white-flowering forms, blooming through May and June on 30 to 60 cm (1-2 ft) stems. Plants grow in both sun or shade, but prefer even moisture and soil rich in organic matter. (Columbines are highly favoured by small green caterpillars known as columbine worms or delphinium worms. In some places, the feeding of these larvae make it nearly impossible to grow these plants without a nearly constant powdering of rotenone. I suppose you could look on the bright side and consider a rotenone-dusted plant yet another addition to the white garden!)Cranesbill, or perennial geranium (Geranium spp.), has a number of white forms, varying from 30 to 60 cm (1 to 2 ft) and blooming in mid-summer above attractive foliage. They do well in full sun or partial shade in most soils.Perennial candytuft (Iberis sempervirens) has evergreen leaves which benefit from snow cover over winter. Masses of white flowers are produced in early June on 30 cm (1 ft) stems. Plant in full sun or partial shade.Shasta daisy (Chrysanthemum x superbum) is often relegated to the back lane because of its tendency to self-seed excessively. ‘Alaska’ has large, single flowers on 60 to 90 cm (2-3 ft) stems, while ‘Silver Princess’ is a dwarf cultivar of only 30 cm (12 in.). Plant in full sun or partial shade.Delphiniums (Delphinium elatum) are stately, old-fashioned plants of 120 to 150 cm (4-5 ft) which do well in full sun in rich, evenly moist soil. ‘Galahad’ is a white cultivar. It will need staking!White perennial flax (Linum perenne ‘Alba’) produces a myriad of small white flowers over a long period in mid-summer. It reaches 60 to 75 cm (24-30 in.) in height. Plant in full sun on well-drained soil. Flowers close at night and in shady or cloudy conditions.Gasplant (Dictamnus albus) is very similar to the peony in foliage and form. It is extremely hardy and long-lived. A white form, called ‘Alba,’ produces white flowers on 90 cm (3 ft) stems in July. All parts of the plant are poisonous. Plant in loamy soil in full sun.Goats’ beard (Aruncus dioicus) is a tall perennial of 1.3 m (4 ft) that is native to the lower reaches of the Swiss Alps. It produce panicles of creamy white flowers in July above feathery, dark green leaves. It does best in partial shade with even moisture.Hostas are shade- and moisture-loving perennials varying in height from 10 cm (4 in.) to 1 m (3 ft). They are grown for their foliage, with many colors and textures, including green and white veriagation.Bearded iris (Iris germanica) has many white forms: ‘Avenelle,’ ‘White Canary,’ ‘Bride’s Halo,’ ‘Country Manor,’ ‘Wedding Vow,’ ‘White Gem,’ and ‘Winter Olympics’ are just a few. All bearded iris prefer full sun and well-drained soil.Lily-of-the-valley (Convallaria majalis) produces small, fragrant white flowers in May and June. It performs best in partial to full shade in evenly moist organic soil. It should be divided every four years to keep it flowering at its best.Lungwort (Pulmonaria spp.) is a useful plant for the white garden primarily because of its foliage, which displays white and silver splotches on a green background. ‘Sissinghurst White’ has the added advantage of white flowers. All grow to about 30 cm (12 in.) and bloom in June. Lungworts require a shady location with organic, evenly moist soil. Peony (Paeonia spp.) - I definitely want some of these, quite a few varieties to choose from.Dwarf phlox (Phlox subulata) has a number of white cultivars. All are low, evergreen, mat-forming plants which bloom in early spring. They prefer full sun or partial shade and do best with snow cover and well-drained soil.Carolina phlox (Phlox carolina) has a white cultivar called ‘White Pyramid’ that grows to 90 cm (3 ft) in height and blooms in July and August. It should be planted in organic, loamy soil in full sun.Grass pinks (Dianthus plumarius), despite their name, have several white forms. They are about 30 cm (12 in.) in height, with grassy foliage and fragrant flowers that look like small carnations produced in mid-summer.Oriental poppy (Papaver orientale) includes a white cultivar called ‘White King.’ It is about 60 cm (2 ft) in height and blooms in June. Plant in full sun with good drainage. Individual plants tend to be short-lived, but they self-seed readily to maintain themselves in the garden.Pussy toes (Antennaria spp.) is a ground-hugging prairie native with tiny grey-green foliage. Plants reach a height of only 5 to 7 cm (2-3 in.), with tiny, nodding white or pink flower clusters in June or July. This rugged, drought-tolerant survivor will thrive and form a dense mat in full sun and good drainage. Plant it in sunny spots amid paving stones in the garden.Rockcress (Arabis spp.) makes an excellent ground cover or plant for the front of the border, with gray leaves and masses of white flowers on 20 cm (8 in.) stems in May. Plant in full sun with good drainage.Sea campion (Silene vulgaris var. maritima) tends to self-seed and may be best suited to an area where it can naturalize freely. It is 15 cm (6 in.) in height, blooms from June to October, and does well in full sun and well-drained soil.Sneezewort (Achillea ptarmica) is a yarrow that produces tiny, button-like flowers in July and August on 45 to 60 cm (18-24 in.) stems. It is useful in fresh and dried arrangements. It has ferny foliage and spreads by stolons. It is best suited to a site with full sun and good drainage.Snow-in-summer (Cerastium tomentosum) is well suited to the white garden both because of its flowers and its silver foliage. It produces masses of tiny white flowers in early summer and is absolutely drought-tolerant. It requires full sun and good drainage.Small soapwort (Yucca glauca) is another perennial that does double duty, valued for both its flowers and foliage. The foliage has a rather unique, grey-green, spiked form with creamy, pendulous bells produced on a 90 cm (3 ft) stalk in July. It is a desert plant which requires full sun and well-drained soil to thrive.Eurasian Solomon’s seal (Polygonatum multiflorum) is a woodland plant which does best in moist, shady locations. It produces graceful, arching stems of 75 cm (2.5 ft), under which pairs of white, bell-like flowers can be found in June.Spike speedwell (Veronica spicata) has many white forms, generally about 90 cm (3 ft) in height, with spikes of white flowers in July and August. Plant in full sun in well-drained but evenly moist soil.Wormwoods or sages (Artemisia spp.) add a gray touch to the night or white garden. Artemisia are ruggedly drought-tolerant, preferring full sun and well-drained soil. ‘Silver Mound’ is a well behaved mound-forming plant about 30 cm (12 in.) high with a slightly larger spread. ‘Silver King’ reaches 60 to 100 cm (2-3 ft) and spreads aggressively if not contained. Artemisia stellerama has an upright form, growing to 45 cm (18 in.), with finely cut leaves. ‘Silver Brocade’ has lacy leaves on prostrate stems. The plants are not aggressive, but will re-seed around the garden. If seedlings are not desired, simply remove the flower heads in early August.Bulbsgrape hyacinth (Muscari spp.)lily (Lilium spp.)ornamental onion (Allium spp.)squill (Scilla sibirica)striped squill (Puschkinia spp.) tulip (Tulipa spp.)Vinesclematis (Clematis spp.)cup and saucer vine (Cobaea scandens)moon flower (Ipomea alba)morning glory (Ipomea tricolor)sweet pea (Lathyrus odoratus)
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