Penstemon Dark Towers
A change from the usual Penstemon, not so much on account of the flowers though they are delightful, but for the dark tints to the leaves and the branching habit of the stems. A wholly beautiful combination. Not as dark, perhaps, as the sticky toffee pudding I’ve just had, but just as moreish!
Penstemons, and this is no exception for all it has such beguiling leaves, are one of the stars of the late summer border and mix well with other late bloomers, grasses and roses too, extending the season of interest late into the year and bringing a whole range of colour with them from rich wine-reds, dark purples and near-blacks, pearly blues, pinks and white – with some of the more modern introductions, strong, solid almost-reds and mauve, whites (and white-throated) and marshmallow pinks. The flowers can be slender (my preference) or wide-mouthed, garish or subtle. Something for everyone then…
Developed at the University of Nebraska, Dark Towers is an outstanding taller selection for the middle to back of a sunny border. It forms a mound of deep purple-red foliage, bearing spikes of bicolor soft and deep-pink bell-shaped flowers in summer. An easy border plant, also tolerant of heat and humidity. Terrific as a cut flower. In particularly rich soil this may need to be staked. A 2008 introduction from TerraNova Nurseries in Oregon. USPP#20013: unlicensed propagation prohibited. Registered with COPF.
Now, here’s Val Bourne with a few words from The Telegraph…. how did you guess!
How to grow: penstemons
Val Bourne on a plant that splashes splendour on autumn gardens
Many penstemons come into their own in early autumn and flower prolifically until the first frosts. Whether added to the border during spring, used as gap fillers in June or planted as a quick fix in September, this versatile plant will obligingly produce one sumptuous spike after another, adding a touch of late splendour to the garden.
Penstemons were adored by Victorian gardeners, who used hundreds of large-flowered varieties in formal bedding schemes. Whole borders were dedicated to them and many had the suffix ‘Bedder’ as part of their name. They lost favour between the two World Wars – fashions changed and most of the 19th-century varieties, which derived from tender Mexican species, couldn’t survive British winters. The final nail in the coffin was lack of plant vigour. Decades of raising penstemons from cuttings had introduced viral disease and many died out.
Mercifully, a number of nursery owners began to breed penstemons at the beginning of the 20th century in an attempt to fill the gap. One red variety called ‘Southgate Gem’ (bred by Bradshaw & Son in 1910) subsequently became the parent of two classic penstemons that are still unrivalled today: the wine-red German variety ‘Andenken an Friedrich Hahn’ (released in 1918), which became a commercial success in the 1950s when it was renamed ‘Garnet’; and the scarlet-red ‘Schoenholzeri’ – or ‘Firebird’ as it was known here – created in 1939 when a Swiss grower crossed ‘Garnet’ with ‘Southgate Gem’. Both make bushy, narrow-leaved plants with lots of flowers, are hardy and have been awarded an AGM.
Also worth growing are ‘Blackbird’ (deep-purple), ‘Raven’ AGM (black-purple), ‘Osprey’ (white and soft pink), ‘Whitethroat’ (purple with a white throat) and ‘Flamingo’ (bright orange-pink with a white throat), although they are not as hardy as ‘Firebird’ and ‘Garnet’.
Edward Wilson, a former student at Pershore College, home to one of the National Collections of penstemons, has raised a series of hardier, large-flowered varieties using P. hartwegii. One of the first, ‘Pensham Just Jayne’, has deep rose-pink flowers with a magenta eye; the shorter, mauve-pink ‘Pensham Miss Wilson’ celebrates Edward’s daughter becoming a teacher.
Never cut penstemons down in the autumn. Leave all the growth intact and wait until late April or early May. Though ‘Garnet’ survived minus 20C in the severe winter of 1981 – a winter that saw off many of my plants – hardiness is a problem with most varieties. However, more are killed by winter wet than severe temperatures, so if your garden has heavy clay soil always plant in spring or summer and add coarse grit. You could also choose a well-drained slope or create a raised bed.
Penstemons thrive in sunny positions and tolerate dry conditions once established. Take cuttings in late summer or early autumn as an insurance policy against loss – using soft leafy shoots about 3in-4in in length. Trim each cutting below the leaf joint, removing bottom leaves, and place three cuttings in a 2-litre pot containing a half-and-half mixture of sand and compost. Place in a cold frame or in a sheltered place and pot up individually in April, to plant out in May or June.
If you’re tempted by penstemons in the garden centre or nursery during late August and September, when they look their best, wait until next spring before you plant them in the border. Keep the plant in a cold frame until spring and take “insurance” cuttings.
Their pretty colours and elegant habit allow penstemons to blend seamlessly into the herbaceous border, however recently planted. You can use them with old-fashioned roses, between daisies (asters, rudbeckias and echinacea) and weave the darker forms through softly flowing grasses such as Stipa tenuissima.
Where to buy
Pershore Plant Raisers, Pensham, Pershore, Worcs WR10 3HB (01386 554672). Send 2 x 1st-class stamps for catalogue. Mail order available – dispatched in spring.
Lodge Lane Nursery and Gardens, Lodge Lane, Dutton, Warrington, Cheshire WA4 4HP (01928 713718; www.lodgelanenursery.co.uk). Send 3 x 1st-class stamps for catalogue. No mail order.
These next pictures are of some of the Penstemon Pensham varieties currently available – there is a link in the article above for an interview with their creator…