Penstemons and Salvias in Autumn
I must admit that I have never paid a lot of attention to Penstemons as I thought they not to be very hardy. But it feels this Autumn as I have discovered them for me – I definitely will use them in my new planting design I am working on at the moment. These elegant border perennials are much tougher than we used to think. Some varieties have narrow leaves and these prove the hardiest. Generally, the broader and fatter the leaves the more tender the plant.
Mid October and they are still in full swing – looking gorgeous in this border in Wisley gardens. Here they are combined with tall Salvias , also great autumn performers.
For the first time I have grown Salvia ‘Amistad’ in my own garden, just to see how it behaves. The first months during summer it was a bit tricky to establish. The slugs loved it and I just let it go thinking if it doesn’t survive the slugs it doesn’t belong into my garden. And then – surprise, surprise, come September it has reached new heights, flowering again and standing tall amongst and above the other plants: Hydrangea ‘Annabelle’, Euphorbia mellifera and Geranium Rozanne.
The best time to plant out salvias is from late May to early June, or as soon as possible after the risk of late spring frosts have passed. This gives the plants the maximum time to establish and get their roots down before winter. If you purchase the plants late in the season, they are best kept frost free and planted out the following spring.
Many Salvias are reasonably hardy if planted in a sheltered sunny position. The soil should not be over rich, and winter drainage must be good. It is advisable to take a few cuttings in late summer as insurance. If required the tender salvias can be lifted, potted and grown on under protection in a greenhouse or conservatory.
Salvias have few demands, but some are brittle and require support (Salvia ‘Caradonna’ in my experience) when planted out in an open or windy position. The frequent removal of old flower heads will promote lots more new flowers. Do not be tempted to trim back and tidy your established salvias until late spring, when the new growth has started and the risk of frosts has passed.
Back to Penstemons. Penstemon ‘Garnet’or ‘Andenken an Friedrich Hahn’ seems to be a strong favourite of many garden designers. It has beautiful pink colour.
Penstemons are easy to grow and keep their foliage over winter. They just need a bit of tidying up after the flowers have faded, just a short prune. In April they can be cut back to ground level once the new growth has started. Even on chalky earth they seem happy,
Penstemon ‘Blackbird’ goes well with red leaved foliage plants such as Pittosporum, Physocarpus or Heuchera.