HARDY PERENNIALS: PENSTEMON

The variety P. ‘Garnet’’ has proved to be the hardiest of a genus, which but for their unreliability under our climate conditions, would rank highly. P. ‘Garnet’ is one of several varieties of P. hartwegii, some of which are popular for summer bedding—such as P. ‘Southgate Gem’ a large flowered pink. They grow to about 2½ feet in bushy formation from a somewhat woody rootstock, and have narrow shiny green leaves. Young plants can be produced from cuttings taken in autumn under glass or in spring from basal shoots and flowering lasts from July to October. A brighter red than P. Garnet exists in P. ‘Firebird’, though this is not quite so hardy, but the smaller flowered P. ‘Pink Endurance’ is so far living up to its name. This has a more slender habit and grows to about 2 feet. Penstemons are not fussy about soil, but they must have good drainage. A very strong point with the above Penstemons is their ability to flower on and on, and young plants, whether nursery grown or not, which have been reared from cuttings taken the previous autumn will bush out and begin flowering by July. From then until autumn they are always in flower, especially if finished spikes are removed. There are incidentally scores of species in existence, some of which are worth trying. P. digiialoides is fairly reliable and as the name denotes is rather like a Foxglove in habit. A new hybrid P. fruticosus ‘Katherine de la Mere’ is semi shrubby, with lilac pink spikes 18 inches high, June to September and this holds the promise of being hardy.

PENSTEMON Garnet

PENSTEMON Garnet

Sorry, comments are closed for this post.