THE plant of the month for June chosen by the Horticultural Trades Association (HTA) is the Penstemon.
Let me explain about the HTA. It is a professional body which represents the horticultural retail trade and those firms that grow ornamental plants.
In a past political life, I argued, unsuccessfully, to make a simple division – the NFU to represent farmers and growers of food crops and the HTA to represent the non-edible crop sector. That would have been too easy for people to understand. Funny thing is, as I write these words, I still think it is quite a good way to distinguish their roles.
Anyway, the HTA publicity machine has nominated the Penstemon as plant of the month for June and I do think it is a worthy choice because this plant has fallen into obscurity in recent times. At one time, it was a great favourite for public displays.
It deserves to have its place in the sun once again because, over the years, there have been significant advances in the breeding and selection of varieties, making them very suitable for planting in modern gardens.
What does a Penstemon look like? We are looking at a herbaceous perennial. Some are described as sub-shrubs – and what the dickens does that mean?
If I were to say that Lavender is a sub-shrub, would that suffice as an explanation? No? Well, it simply means that, in milder areas, the plant develops a perennial stem framework but most of the growth remains herbaceous. Another good example is the Cape Figwort, Phygelius (we actually grew this plant as a wall shrub at Auchincruive, where it reached a height of two metres).
To get back to the point, it is best to regard the Penstemon as a herbaceous perennial, with heights varying from 30cm (12in) to 120cm (4ft). Some of the dwarf species and their cultivars are suitable for rock gardens.
My father would have used penstemons in his summer bedding schemes, treating them like geraniums – in other words, half-hardy perennials. As you can see from the pictures, the flowers are tubular, carried close together in clusters, mainly racemes or, to use a familiar analogy, a bit like foxgloves.
They flower from midsummer well into the autumn, especially if you are on the ball with your dead-heading to encourage the growth of side-shoots. The colour range is good – from deep red through the pinks to white and then lavender to deep purple. Some, like Penstemon “Pensham Laura”, are bicoloured.
Herbaceous Penstemons like full sun and good drainage. The original species from which the modern hybrids are bred belong to the Americas, mostly the western seaboard. I’ve seen it quoted somewhere – from Alaska to Guatemala.
One of the parents of these modern hybrids is P.hartwegii, from Mexico, and another, P.cobaea, is from the US (Arkansas and thereabouts).
What does this little bit of info tell us? They are marketed as hardy herbaceous perennials, and you can bet that information emanates from south of Birmingham. In other words, it is a bit colder in these parts, need I remind you?
Penstemons are definitely on my agenda to try in the new garden. The last one I tried up the road was a cracker called “Sour Grapes”. It has lovely deep lavender flowers with a wee touch of pink in the throat. It lasted a couple of winters in a sheltered, south-facing border.
What I am saying is, by all means plant Penstemons – they are very handsome plants, flowering over a long season – but be sure to give them a sunny situation, and always have a few cuttings on the go. Take them just as you would geraniums or fuchsias and then you will not be disappointed if you lose an odd plant. You can protect the plants in situ overwinter by giving the crowns a dry mulch.
As it happens, my colleague, Carole, has organised an observation trial of these modern Penstemons at Beechgrove this year. They are only just planted out and she has them in a very open, sunny raised border. I can’t wait to see how they fare.
New product
I was very intrigued by this one and thought it worthwhile to bring it to your attention since it is weather-related.
Straight from the press release: “Inspired by the sheep on her own Suffolk farm, a homeware designer has invented a ground-breaking treatment to create a range of stylish waterproof outdoor cushions and tablecloths that can be left outside whatever the weather.
“It all started when Julia was looking for some outdoor cushions for her own garden – ‘I knew from my own sheep that their wool would make a perfect natural filling for the cushions’.”
Golly gosh! For more information, go to www.oilyragfabrics.com