The Pentstemons are beautiful border plants but do not do as well in the Northern States as in the Southern ones, where the climate is milder and the season of blooming is longer. They are very showy, growing from 2 feet to 4 feet high, are rather bushy and have very long, slender spikes which bear many trumpet-shaped flowers with hairy throats from whence the name “Beard Tongue” comes. The colors range from white, pale rose, azure blue, lilac, coral, scarlet, violet and purple.
Pentstemon barbatus Torreyi has slender, deep scarlet-red flowers. The foliage is light green and the stems are wiry and thin, giving an airy appearance to the whole plant. P. gloxinioides Sensation has Gloxinia-like flowers of varying colors-rose, lilac, cherry, crimson and purple. It grows about 2 feet high and is in bloom nearly all Summer.
P. Digitalis has white flowers with a purple throat, grows 2, or 3 feet high and blooms during June and July. The Pentstemons somewhat resemble the Snapdragons, both in flower and in growth. Often the flowers are two-colored, the petals being of one color and the throat of another. The flowers last from June through October.
How to use Pentstemoms
Pentstemons are very free blooming and are good for cutting purposes. Their graceful growth and variety of colors make them easily adaptable to almost any perennial border. The dwarfed ones are grown in rockeries.
Where to plant Pentstemoms
A good, deep garden soil mixed with leafmold or sandy loam, in a well-drained situation which is somewhat shady, is the best place to grow Pentstemons. They like plenty of water in the:
Summertime. Many are hardy, but Sensation requires mulching during the Winter; even then, in the colder climates it freezes out. Good drainage and loose, loamy soil are absolutely necessary to the growth of Pentstemons.
How to grow
They are propagated either by division, seed or cuttings. Cuttings should be taken in the Autumn, which is also the time to divide the roots. Plants may bloom the first year if the seeds are sown early. The varieties of P. gloxinioides are well treated as annuals, sowing the seed each year.