Diary - My 10 favourite Perennials

My 10 favourite…………………………………..PERENNIALS

Astilbe (Astilbe X arendsii) (Garden Astilbe) (Sun to partial shade)
Zone 3 Ht: 24-36” Spr: 18-24”

Feathery flower plumes in many different colours (from pink to white to red). Foliage is lacy. My favourite red is ‘Fanal’ and favourite white is ‘Deutschland’. They love partial to full shade and adore moist, mulched soil. Depending on the type, different astilbes will bloom June – August


Aquilegia (Columbine) (Sun to partial shade)
Zone 2

This is an old fashioned perennial that’s lovely in the spring landscape. The Hybrid strains are the most commonly grown and my favourite is ‘McKana Giants’ (Height: 30-36”). The flowers hang like large winged bells and come in a variety of soft shades. Another columbine that appears in my garden year after year (wherever it chooses!) is Wild Columbine (Aquilegia Canadensis Height: 2-3’) with delicate red bell flowers with yellow centers. It obviously self seeds.

3. Hemerocallis (Daylilies)
Zone 2
18 years ago, my friend’s father brought me a clump of daylilies for my new house. “One-a-Day Lilies” he called them. I smiled, knowing that he had the name confused with One a Day Vitamins, but when I thought about it later – he was right! Each flower only blooms one day, but there are often 12-14 blooms on each stem, making the plant full of flowers for weeks on end. In sun or shade, colours may range from yellow to red to purple to almost black! Hundreds and hundreds of cultivars exist and more appear in nurseries each spring. Their leaves are grassy-looking and fit well into a border. My ultimate favourites are ‘Hyperion’ with large, fragrant yellow blooms; the ‘Chicago’ series and ‘Woodside Ruby’, a dark ruffled, deep red shade. Also, in my opinion ‘Happy Returns’ is better than the famous ‘Stella D’Oro’ for repeat blooms. The only ones I advise against are the common orange ones that grow in ditches. These spread like crazy and can take over a flower bed in no time flat! Trust me, I know!

4. Polygonatum (Solomon’s Seal)
Zone 3
This shade-loving, spring blooming perennial has gently-arching green striped leaves with tiny, delicate bell flowers hanging underneath. It is delicate, elegant – a real harbinger of spring. The bloom period is relatively long, especially if the ground stays moist. The most common is Polygonatum x hybridum (Common Solomon’s Seal) but other fun varieties include Polygonatum commutatum (Giant Solomon’s Seal) which can reach 7’ in very rich soil and Polygonatum odoratum var. pluriforme ‘Variegatum’, a variegated version with creamy white and green striped leaves.

5. Penstemon digitalis ‘Husker Red’
Zone 3 Ht: 30-36” Spr: 12-18” Full Sun
I love my Penstemon ‘Husker Red’! (Perennial of the Year in 1996). Deep burgundy clumps of leaves emerge in spring slowly changing to green with tall stems holding delicate pinky-white bell flowers. ‘Husker Red’ looks great massed together in a drift. (I have about 7-8 plants together in one area). They last for a week or more as cut flowers and people often comment that they look more like silk flowers instead of real!

6. Hosta
Zone 2 (Sun or partial shade or full shade).
Hostas are almost as plentiful in variety as Hemerocallis (Daylilies). There are hundreds of different types ranging from tiny to huge! Ones that have done particularly well in my garden (which ranges from full sun to complete shade) are: ‘Blue Wedgewood’ (Ht: 12”); ‘Night before Christmas’ (Ht: 20-22”); ‘Frances Williams’ (Ht: 24-28”); ‘Golden Tiara’ (12-16”); ‘Great Expectations’ (20-28”); ‘June’ (12-16”); ‘Paul’s Glory’ (22-26”); ‘Sagae’ (30-32”); sieboldiana ‘Elegans’ (24-30”); ‘Sum and Substance’ (30-36”). Hosta love moist soil but watch for slugs near the thin leaf varieties! Slugs and snails think Hosta are delicious as a midnight snack!

7. Rudbeckia (Black-Eyed Susan) Rudbeckia fulgida ‘Goldsturm’ (Full sun)
Zone 3 Ht: 24-30” Spr: 18-24”
‘Goldsturm’ is a very familiar, very reliable Rudbeckia cultivar. Lovely bright golden daisy-like flowers with a dark brown ‘eye’. Books and guides often call it a late-blooming flower. I always thought that meant September but in my garden it already opens in late July and is gone by mid-August. Nonetheless it gives any border a “happy” quality and while it’s blooming and attracts very few problems or pests.

8. Iris sibirica (Siberian Iris) (Sun to partial shade)
Zone 2 Ht: 24-40” Spr: 18-24”
A very elegant, stately addition to any border! Siberian Iris love rich moist soil (add manure!). Strong slender upright stems rise above clumps of grassy foliage in late May and early June. My favourites are the dark blue/purple bloomers as well as the light blue/mauve but Siberian Iris are also available in rose, yellow and white.

9. Perovskia (Russian Sage) (Full Sun)
Zone 4 Ht: 3-5’ Spr: 24 – 36”
Perovskia is a large but delicate focal point in a border. Quite tall (4-5’) and half as wide, dainty mauve flowers dot the long upright stems. When rubbed, the flowers and leaves exude a distinct herby fragrance. I’ve never had much luck using beautiful Russian Sage in fresh flower arrangements – the little flowers end up in a pile around the vase in a very short while. But in the garden, it peaks in August and September and turns an interesting grayish-white in late fall and early winter. Don’t trim it lower than 2’ for winter and only to 6-8” in spring or you won’t have much of a show the following summer.

10. Coreopsis verticillata ‘Moonbeam’ (Thread Leaf Coreopsis ) (Full sun)
Zone 4 Ht: 12-18” Spr: 12-18”
I incorporated this beautiful, dainty yellow bloomer into almost every garden I designed! One of my all-time favourites, pale yellow flowers rise over ferny foliage. It was proclaimed the 1992 Plant of the Year. If divided every 3-4 years, it will retain its vigour. I am not as fond of coreopsis rosea (pink flowered coreopsis) probably because their flower fades to white in really hot summers but 2 others I’m starting to really like are: coreopsis rosea ‘Limerock Ruby’, an interesting ruby-red shade (that doesn’t seem to fade) with a yellow eye and coreopsis verticillata ‘Zagreb’, a bushy form similar to ‘Golden Shower.’

Honourable Mentions:

Alchemilla Mollis (Common Lady’s Mantle) (Sun to part-shade)
Zone 2 Ht: 12-18” Spr: 18-24”
I remember first seeing alchemilla mollis on a garden tour in Toronto in the early 90’s. My friend and I asked the garden guide what the flowers would be like when they emerged. She answered “That’s them!” She must have noticed our disappointed faces as we stared at the soft lime green flowers on the large scalloped leaves because she quickly added: “But no one grows them for the flowers! You should see them after a rainfall – the leaves catch drops of water that sparkle like diamonds later in the sunshine!!” Our faces lit right up as we scribbled down “alchemilla mollis’ to add to our nursery lists. Now I can’t imagine my garden without it. It thrives in wet or dry and is not fussy in the least. Not a showpiece in itself, but a must-have as a background for all the other showpieces! (And raindrops really do sparkle on the leaves like diamonds in the sun after a shower!!)

Dictamnus albus (Gas Plant) (Full sun)
Zone 2 Ht: 2-3’ Spr: 2’
Another Toronto Garden Tour discovery! Wonderful strong tall stems hold airy spikes of white or pink (var. purpureus) flowers. I was warned that it takes up to 3 years until the gas plant becomes truly established and puts on a show and that I must be patient (not one of my strong points). But the advice was correct – now every summer the beautiful gas plant rises in a small corner near my arbour and I look at it in sheer delight. It hates to be moved, so find it a permanent home and leave it be.

Heuchera (Coral Bells) (Full sun to partial shade)
Zone 3-4 Ht: 10-30” Spr: 18-24”
I have 2 distinctly different types of coral bells in my garden and I love them both! Heuchera x brizoides hybrids has low clumping, rounded leaves which produce long stick-like stems with tiny coral-coloured bell flowers on the. Lovely additions to a vase combo (they’re so dainty!). If well watered, coral bells last for months in a semi-shaded garden. My other favourite is one of the Americana hybrids called ‘Palace Purple’. It has dark burgundy-brown leaves with sprays of creamy white flowers above. Again, it’s used more for foliage than flowers. Looks great with hosta.

Gaillardia (Blanket Flower) (Full sun)
Zone 2 Ht: 18-24” Spr: 12-18”
3 great blanket flowers add a splash of colour to my garden starting in late June. One type has yellow tips with burgundy centers (‘Goblin’); others are solid yellow (‘Golden Goblin’) and one of mine is a deep wine red (‘Burgundy’). Dead-heading ensures constant summer bloom. Another ‘happy’ plant! Really cute!

Underused Perennials

Eryngium giganteum (Sea Holly) (Full sun)
Zone 3 Ht: 30-36” Spr: 12-18”
My husband was helping me pull thistles from my flower beds but (smart man!) always checked before actually yanking the weeds out. “This one?” he asked. “NO!” I screamed in horror, “that’s my Sea Holly ‘Miss Wilmott’s Ghost’!” “OK, OK, just checking” he mumbled as he moved deeper into the garden-jungle. This is one of the coolest, new flowers to grace my border and I just love it. Tall, with large silvery gray flower bracts that have sharp spiky thorns. It starts out pale, pale mauve and fades to grayish-white. A real eye-catcher and visitors always ask about it. Dies after flowering but self-seeds.

Brunnera macrophylia (Siberian Bugloss) (Partial to full shade)
Zone 4 Ht: 12-18” Spr: 12-18”
The small sky-blue flowers of bugloss are often mistaken for forget-me-nots, but this garden beauty is actually its aristocratic cousin. Brunnera is a spring bloomer with masses of large, heart-shaped leaves. A few years ago ‘Jack Frost’ created quite a stir (and broke a few budgets at $20-40 a plant!) because of a totally new look: it had frosty silver-coloured leaves that had mint-green veins! The blue flowers looked superb against this interesting background.

Cynara cardunculus (Cardoon) (Full Sun)
Zone 7 Ht: 3-6’ Spr: 3’
This year, my city’s boulevards featured Cardoon as its focal point surrounded by fuschia and purple petunias. Grown in my area as an annual, Cardoon features arching, spiky silver leaves that produce tall, globe thistle-type flowers in late summer. This rare eye-catcher could be an excellent design feature in your garden.

Scabiosa caucasica (Pincushion flower) (Full sun)
Zone 4-9 Ht: 20”` Spr: 8”
Years ago I ordered seeds from an American seed company (when there wasn’t such a huge difference between the Canadian and American dollar!). The seeds were expensive even then ($1 a seed!) but I grew a pincushion flower called ‘Fama’ with intense blue/mauve blooms. What a beauty and it’s still going strong 15 years later ( and I’ve moved it twice.) It’s beautiful as part of a vase flower arrangement and everyone always asks about it.