PLANT OF THE WEEK #102: Penstemon 'Blackbird'

I’ve always been in two minds – maybe more than two – in regard to penstemons.

Yes, they’re generous in bloom, and yes, they come in a good range of colours.  They flower for an incredibly long time, provided they don’t get too dry.  Indeed they’d likely flower nearly all year in a frost-free temperate climate, with a little summer irrigation.

Penstemon ‘Blackbird’ in the foreground, centre and left, in planting at Stone Hill, along with Salvia ‘Caradonna’, Agastache ‘Sweet Lili’, Stipa gigantea and hollyhocks

But I just can’t seem to love them.  There’s often too much foliage for the amount of flower they offer, and the foliage is without any distinction, making little or no contribution to a planting.  And while I’m a total sucker for tubular flowers that taper up a vertical stem (like foxgloves, for instance), the flowers on too many penstemons are overly chunky and congested, making for good colour presentation but with no grace or elegance.

Penstemon ‘Blackbird’ with Sedum ‘Matrona’, Geranium ‘Roxanne’, Aster x frikartii ‘Monch’ and Calamagrostis ‘Karl Foerster’ at my place

Enter Penstemon ‘Blackbird’.  The foliage has a narrow, willowy quality that earns the plant a few entry-level elegance points.  And the flowers are a rare perfect match, presenting as slender tubes that flare open at the end, but with such open, free spacing that you’re more likely to engage with the sides of individual flowers as well as the flared ends, than you do with the fatter-flowered forms, in which you’re much more restricted to looking into their wide-open mouths.  In most of these latter forms, the leaves present as a smug tump, and the flowers hover, disconnected, overhead, but with Penstemon ‘Blackbird’, the leaves rise up the vertical flowers stems in places to play a little amongst the flowers, topping out at about 1.2m.  

Then, of course, there’s that wonderfully rich plum colouring, undiluted by spots or blotches of white, creating a fabulous bass-note in either a safe and tasteful pink and mauve colour scheme, or a racier, hot one.

All good reasons why, if I’m tempted to (or in the case of unavailability of other stuff, forced to) use a penstemon in perennial plantings, Penstemon ‘Blackbird’ is the only one l ever specify. 


  1. I love the Penstemon family and find they are so easy to maintain. They look good most of the year, especially when the dark colours are back lit. In my garden they are attractive to the small native honey eaters along with my favourite wattle birds. I use them in clumps of usually three amongst native grasses, shrubs and groundcovers.

  2. I know you are not a fan of roses either Michael but in my last garden I used Penstemon ‘Blackbird’ alongside Rosa ‘Bonica’ a soft pink cluster flowered heritage rose underplanted with Nepeta ‘Walkers Low’ — it created a stunning picture. I also love P. ‘Alice Hindley’ for its upright growth and lovely mauve and white flowers. I agree though that (even though I have many) penstemons can be ragged in winter, sprawling in summer and difficult to place. I hope to still use some in my next garden though, hopefully they will fare better than they have on my poor soils here. Like Yvonne, I too have noticed how much the honey eaters love them. Your ‘Blackbird’ looks stunning BTW.

  3. I enjoy growing them in my garden. They’re lovely with Nepeta, Dianella and Erigeron, happily sprawling in the middle of the garden beds and shaded from the afternoon sun, mine are fine without additional water in summer. I love how easy they are to divide and create a pleasing repetition with around the garden. I’ve found they look best if given an annual hard prune and don’t plant them too close to the paths where they will flop. I’ve just addd some Delphiniums to the mix this year so fingers crossed for a pretty blue/ purple picture later in the year.

  4. Live in relatively cool, damp area almost frost free with rain throughout the year. No droughts here. Penstemon thrive here and do Flower almost all year. I do cut them back hard in late winter to force them to take a break. As it’s too wet here for many of the salvia family and the likes of lavender and agastache I wouldn’t be without penstemon …

    Except for the chunky fire engine red variety…too bright to be a living plant !!

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