Echinacea purpurea (Coneflower, Echinacea)
Cultivars include 'Magnus' (deep rosy pink with dark orange disks) and 'White Swan' (white with orange-brown disks). New cultivars include 'Kim's Mophead' (similar to 'White Swan' but half the height) and 'Kim's Kneehigh' (a purple coneflower half as tall as traditional types). Reliable, tough and much loved. Tolerant of heat, drought and poor soil. Doesn't need staking. Blooms from July to September. Attracts bees and butterflies. Stalks can be left standing over winter. Height to around one metre (3'). Zone 3.
Echinops ritro (Small Globe Thistle)
This globe thistle has dramatic, metallic-blue round, architectural, spiky blooms. (60 cm - 24"). Blooms June to September. Average to moist, well-drained soil. Zone 3.
Gaillardia x grandiflora 'Burgundy' or 'Dwarf Goblin' (Blanket Flower)
A tough perennial that withstands hot, dry conditions and is very drought tolerant. Will bloom itself into oblivion if allowed. Cut back in September. Good butterfly attractant. (Cultivars are 30-60cm - 12-24" tall.) Watch for slugs, snails, mildew, rust. Zone 3.
Gaura lindheimeri (Butterfly plant or White Gaura) 'Whirling Butterflies' and 'Siskiyou Pink'
This plant has delightful, airy blooms on long, (60 cm), thin stalks. Grey-green leaves, white or pink flowers with red sepals. Flowers from June to September. Height to 1.5 m - 5' Likes sun or part shade. Tuck this plant behind a lower plant in the border to hide its legginess. New cultivar is 'Crimson Butterflies'- a dwarf form of 'Siskiyou Pink' with foliage that changes colour. Zone 5.
Gypsophila paniculata (Baby's Breath)
Airy mound of loose, small white flowers are borne on branching stems in mid- to late summer. (1.2m - 4' height and spread). Full sun, deep, well-drained soil. Doesn't like wet feet in winter. Can be prone to crown gall and bacterial rots. Zone 4.
Helenium autumnale hybrids (Fall Helenium, Sneezeweed)
Bright vivid yellow, orange, gold or red daisy flowers from July to September. Need lots of moisture during the summer. Sap can irritate sensitive skin. Full sun. To 1.5m - 5' tall. Zone 3.
Heliopsis helianthoides 'Loraine Sunshine' (Ox eye daisy)
Very unusual plant with variegated foliage (silver in between the dark green veins). Large golden-yellow flowers from June to October. Reaching 75 cm tall. Full sun.
Hemerocallis cultivars (daylily)
Generally hardy to Zone 3, daylilies come in many shapes, including triangular, circular, double, star-shaped and spider-shaped; and a wide range of heights and colours and bloom times. Most daylilies prefer a fertile soil and full sun but will perform in partial shade. Their sword-like leaves form a handsome fountain throughout the season. Ask for late-season cultivars and be rewarded with blooms in the August garden. Repeat blooming cultivars include 'Stella d'Oro' (bright yellow-orange) and 'Happy Returns' (softer yellow, slightly taller plant) and the new 'Pardon Me' (red). Zone 3.
Kniphofia hybrids (Red Hot Poker)
Provide full sun and rich, well-drained soil. Long, narrow leaves with brilliant yellow, orange or red 'firecracker' blooms. Some cultivars have all 3 colours on each flowering spike. Attracts hummingbirds. Blooms June to September. Doesn't like wet feet in winter. Heights 60 to 100 cm depending on cultivar.
Leucanthemum x suberbum cultivars (Chrysanthemum maximum, shasta daisy)
Old fashioned favourite for a sunny perennial border. Singles, doubles or
semi-double white blooms. Blooms from June to September. Lots of height
variation with new cultivars. From 30 cm to 1 m tall.
Liatris spicata (Blazing Star, gay feather)
Tall spikes of rosy-purple bottlebrush-type pink-purple or white blooms at the tips of the plant. A good substitute for purple loosestrife. (To 1.5m - 5') Blooms July to September. Must have well drained soil. Full sun. An easy to grow perennial. Tough and drought resistant. Zone 2.
Ligularia (grows 3 to 5 feet).
Coarse-looking plant with interesting foliage, spikes or bunches of yellow blooms. Like moist soil/full sun-part shade. Forms clumps, can be aggressive. Zone 4.
Lobelia cardinalis (Cardinal flower)
A native wildflower that is happiest growing in a moist site along side a stream. Gardeners and hummingbirds love its bright red blooms. (To 90 cm - 36").Will self-seed and form an attractive colony. Full sun/part shade.
Lobelia x speciosa (Hybrid cardinal flower)
A cardinal flower look-alike, but with blue, deep red, orchid rose or scarlet blooms.
Lysimachia clethroides (Gooseneck loosestrife)
Distinctive white flower spikes from July to September. Best in part shade in a moist site (similar to Lobelia cardinalis). Be careful! Can be aggressive. 60-90 cm (3') tall and wide. New cultivar 'Geisha' has variegated leaves and is reputed to be less invasive.