1. Giant Fleece Flower
Name: Persicaria polymorpha
Zones: 4 to 9
Size: 4 to 6 feet tall and 6 to 12 feet wide
Conditions: Full sun to partial shade; average to moist soil
This “astilbe on steroids” quickly attains the mass of a shrub, and has an impressive presence before and after its June-through-September bloom. Its size is best suited to the back of a border or the middle of a deep flower bed. It does not seed or ramble. Division is better done in spring or after leaf loss in fall as its hollow stems break easily. Giant fleece flower’s plumes make a good backdrop for colorful cannas (Canna spp. and cvs., Zones 8–11), and it is a good companion for tall ornamental grasses.
2. ‘Siskiyou’ Evening Primrose
Name: Oenothera speciosa ‘Siskiyou’
USDA Hardiness Zones: 5 to 8
Size: 10 to 12 inches tall and 12 to 18 inches wide
Conditions: Full sun; poor, well-drained soil
This tough perennial is floriferous from early to midsummer and is tolerant of drought. Place it at the front of a border, where it will ramble, or on hillsides for quick cover and resistance to erosion. But watch out: If not maintained, ‘Siskiyou’ evening primrose can sometimes take over and be difficult to eradicate. Pair it with ‘May Night’ salvia (Salvia sylvestris ‘May Night’, Zones 5–9) or Russian sage (Perovskia atriplicifolia, Zones 6–9).
3. ‘Princess Diana’ Clematis
Name: Clematis texensis ‘Princess Diana’
Zones:5 to 9
Size: Vining up to 6 to 8 feet
Conditions: Full sun to partial shade; rich, moist, well-drained soil
‘Princess Diana’ clematis may be the longest-blooming texensis clematis there is. Its elegant, 1½-inch-wide bells of saturated dark pink with a lighter pink edge will not fade in full sun, and the vine will still be floriferous in partial shade. This cultivar can weave through conifers and shrubs without blocking the sun, as larger-flowered clematis do. Whether grown up an obelisk, over a wall, or through a shrub, this plant needs a companion that appears early, like hellebores (Helleborus orientalis, Zones 4–8) or ‘Aureola’ Japanese forest grass (Hakonechloa macra ‘Aureola’, Zones 5–9), to skirt its bare base.
4. Autumn Charm™ Sedum
Name: Sedum ‘Lajos’
Zones:4 to 9
Size: 14 to 18 inches tall and 18 inches wide
Conditions: Full sun to light shade; well-drained soil
Autumn Charm™ is a sturdy, dependable variegated sport of ‘Autumn Joy’ sedum, with showy blue-green leaves edged in a creamy yellow that ages to creamy white. Its flowers are rose pink and appear later than those of ‘Autumn Joy’. As with other sedums, its leggy tendencies can be controlled by removing half its height in June.
Mindy Arbo is co-owner of the Cotton-Arbo retum, a privately owned public garden in Winchester, Massachusetts.
Photos: courtesy of Mindy Arbo, Michelle Gervais, Kerry Ann Moore, courtesy of www.perennialresource.com