This might be the year to take your time when choosing perennials because the largest wholesale supplier in B.C., Valleybrook Gardens (renamed Joya Growers Ltd.), has officially been shuttered. So those trademark Heritage perennials in blue pots and the dazzling selection Valleybrook Gardens provided will no longer be available, although the remaining suppliers are working hard to fill those gaps. That said, Valleybrook was such a big player in the Canadian market that there are bound to be major perennial shortages this year. So, to help you out with this dilemma, I thought I would revisit the topic of the longest-blooming perennials, those that flower for months on end and provide the best value for your garden.
I’ll present them from the earliest blooming to the latest so that you can plan your perennial display with year-round colour in mind.
Helleborus ‘Ice N’ Roses Early Rose’
Bloom Time: Late November till April
While the breeder claims that the blooms of this hybrid Hellebore begin showing in November, I can tell you that the plants I have had in stock since mid-January, have been in flower all that time and are still loaded with unopened buds. The blooms are shell pink when they emerge, fading to a darker rose with age. Helleborus ‘Ice N’ Roses Early Rose’ is a new introduction that tolerates full sun exposure. Grows 20-24” tall. Hardy to USDA zone 5.
Primula veris
Bloom Time: April to May
Cowslip is an old-fashioned cottage garden favourite and also an Award of Garden Merit winner. It is long-lived, naturalizes well, and produces abundant racemes of fragrant butter-yellow blooms that are edible and are even used to make a flavourful wine. Primula veris tolerates full sun in coastal gardens but will require partial shade in the interior. Grows 6-10” tall. Hardy to USDA zone 3.
Iberis ‘Mermaid Lavender’
Bloom Time: Spring Through Summer
Iberis 'Mermaid Lavender' is an exciting new 2022 introduction with bold lavender-purple blooms that are borne continually from spring right into summer. It is highly attractive to pollinators and is resistant to both deer and rabbit damage. The intensive breeding also makes it both heat and drought-tolerant, making it an ideal cottage garden perennial. Grows 15-18” tall. Hardy to USDA zone 5.
Zantedeschia ‘Kiwi Blush’
Bloom Time: May to July
Zantedeschia ‘Kiwi Blush’ is a lovely New Zealand introduction with glossy deep green architectural foliage and stunning spathes of pure white with a heart of shell pink. These make great cut flowers and although this perennial is a little tender, it should be fine when grown in foundation beds or large containers. If you decide to grow in containers, overwinter the pots from late fall in a shed or cool greenhouse and stop watering until March. Grows 24-30” tall. Hardy to USDA zone 8.
Monarda ‘Pardon My Purple’
Bloom Time: Late June to August
Monarda ‘Pardon My Purple’ is a compact Bee Balm from Proven Winners with dark fuchsia blooms throughout the summer. It is a cross of ‘Grand Parade’ and ‘Grand Marshall’ that has proved to be quite resistant to powdery mildew and has a longer flowering period. Given its hardiness and compact size, this would be another good choice for container culture. Grows 10-12” tall. Hardy to USDA zone 4.
Verbascum ‘Jackie’
Bloom Time: Early to Late Summer
This stunning ornamental Mullein produces striking spires of creamy-apricot flowers with a contrasting pink eye. Verbascum ‘Jackie’ makes a great cut flower and when deadheaded will bloom throughout the summer. The dense rosette of fuzzy green basal leaves is quite tidy, which makes this compact cultivar a great accent for a patio container. Grows 16-18” tall. Hardy to USDA zone 5.
Leontopodium alpinum
Bloom Time: July to September
Edelweiss produces very distinct white felted flowers in abundance from late spring to early summer, and sporadically afterwards until September. This European alpine perennial requires well-drained neutral soils and full sun, so it might be best to stick to raised rockery beds. The name is German and is derived from ‘Edel’ (noble) and ‘Weiss’ (white). Grows 6-12” tall. Hardy to USDA zone 4.
Diascia ‘Coral Canyon’
Bloom Time: July to October
This perennial form of Diascia or Twinspur was discovered in the mountains of South Africa and bears masses of coral-pink blooms from summer into autumn. Deadheading (particularly in its first year) will help prolong the flower display and enable a newly-planted specimen to root in properly. While this perennial has few pest problems except slugs, it can be short-lived, particularly in wet soils. Grows 12-18” tall. Hardy to USDA zone 5.
Perovskia ‘Denim ‘n Lace’
Bloom Time: July to October
Perovskia ‘Denim ‘n Lace’ is another late-blooming perennial from Proven Winners that was bred for its compact size and capacity for staying upright without support. The sky-blue flowers last for months and attract both pollinators and hummingbirds. As a side note, the blooms are edible and add a lovely dusting of colour and a sage flavour to any fresh salad. Grows 28-32” tall. Hardy to USDA zone 4.
Rudbeckia triloba ‘Prairie Glow’
Bloom Time: Midsummer to Frost
This short-lived perennial is a must-have for cottage or meadow gardens and readily persists through self-seeding. It is smothered with hundreds of smaller reddish-orange blooms that are tipped in gold and encircle a chocolate brown cone. Look for this hard-to-find perennial later in the season and be prepared for all the butterflies who are bound to seek them out. Grows 3-4’ tall. Hardy to USDA zone 4.
