A Exploration of the genus Calamagrostis

Inflorescence of Calamagrostis x acutiflora 'Karl Foerster'

 The genus Calamagrostis consists of 250 species found throughout the northern hemisphere in a variety of  environments, with 12 species being natives of North America. This wide distribution has resulted in the genus duel-ability and thus its recommendation for some of the toughest of garden conditions. Members of the genus can be found in riparian  glades, forest, and grasslands.The majority of this genus prefer full sun to part shade and are evergreen to semi evergreen in nature. This makes them low maintenance but also a source of refugee for overwintering invertebrates. The flowering stalks emerge late in the growing season and come in a variety of tans to more pinkish hues, overall shape however is very reminiscent to a more skinnier opener pampas grass in structure. The majority of these grasses are considered to be cool season grasses, which means majority of growth is done when cooler frost free temperatures are readily available, however they do tolerant heat.
    Our exploration into this genus was one that was started last year, in the fall.It was the final weeks before the frost and on a trip to the local Lowe's I had visited the discount corner and discovered several plants one being Calamagrostis brachytricha. It was in that moment that our exploration into the genus truly kicked off. It was one of the first grasses to find residents in the garden, and it proved to both I and my parents that there was more to grasses then meets the eyes. Although they are all similar in form and structure it was there performance that wooed us over.  Soon after our first Calamagrostis we have added three more. All added this year there performances as individuals has so far been good and shall be explored below.

Calamagrostis brachytricha

The first Calamagrostis to be planted in the garden and also the one of the first grasses to be planted as well. Native throughout China this species is a warm season grower, which refers to the fact that the grass does most of its growth during the heat of the summer vs cool season which does it in the spring, with flowering happening in late summer a characteristic that can be applied to the genus as a whole. Preferring to grow in either sun or part shade this species prefers moist well draining soils. However in my own garden it has been demonstrated that C. brachytricha has a a tolerance to the dry heat that is found in area of the garden that we nicknamed the Hell strip. The soil here is dry sand and hot to the touch neither the less C. brachytricha has relished in these conditions.
   Described as a semi-evergreen to evergreen plant , our own specimen thus far has remained evergreen. yearly maintenance , and this can be prescribed to the rest of the Calamagrostis discussed, consists of pruning dead foliage flushed to the ground. Prune them and flowering stalks to ground leave to avoid leaving stubs which only create a crowed environment and cause the plants center to die out. Inflorescence are tan in color with this species reaching a height of three feet foliage wise with a 4 foot height during flowering. Please note that this species does have the ability to self sow. In my own garden this has yet to occur but if it did I'll be ready to share!
Calamagrostis x acutiflora 'Karl Foerster'

   Discovered in Hamburg botantical gardens in the 1930's it was believed to be a chance hybrid between C.  epigejos and C. arundinacea  and was later named after the man who discovered its genetic history,  German plantsman Karl Foerster.  It has proven to be such a popular plant that in 2001 it won The Perennial of the Year award. Semi evergreen in nature it requires the same annual maintenance as C. brachytricha.  Its mature height is also similar to that species however its growing habit is of a more upright habit. It is this upright habit and its tolerance of neglect that has award the plant with its everlasting popularity.  This upright habit has seen it used as a focal point throughout a multitude of gardens and rightfully so. Its upright habit also encourages its use in small gardens. In my own garden however it is part of a ridge planting that separates and blurs the cottage and tropical plantings. Its flowers are tan in color, similar shape to many of the species but slightly skinnier. In contrast to C. brachytricha which can self seed , Karl Foerster is sterile.
   This is  this plants first year ( was planted a month ago) is slowly establishing itself. It is in the back of the ridge planting on the side of the cottage plot. It sways in the wind with grace, providing movement in a section which features more solid plants. The hope is that like many other grasses it provides it provide year round interest and habitat for wildlife.
  Calamagrostis x acutiflora 'Karl Foerster' has since given rise to three other cultivars by means of spontaneous mutations.  In our own garden we have two of these cultivars which you can see below.
Calamagrostis x acutiflora 'El dorado'

   Calamagrostis x acutiflora ' El Dorado' was purchased in the spring is the second oldest of the 4 in the garden. First spotted in as a division of Karl Foerster it feature variegated foliage which is internalized by dark green and edged by bright yellow. It reaches 6 feet when in full flower which is typically in the late summer to early fall. Inflorescence emerge green and with age gain a purple tint , finally maturing to tan. My own plant has yet to flower but then again this is its first year, hopefully next year it shall grace us . Much like its parent and typical of the genus as a whole inflorescence last through the winter but can quickly deteriorate if the winters are to harsh. Its main attraction is its foliage which is striking especially in a shaded position. In fact this plant prefers part sun conditions as the foliage color might lose vigor if over exposed. Its for that reason that our own specimen finds residents under the shade of Cestrum 'Orange peel'. Similar in growing habit to its parent , it maintains a upright habit and is good for small gardens.

Calamagrostis x acutiflora 'Overdam'
 

 The cultivar 'Overdam' is very similar to another known as 'Avalanche'. The major difference being the pattern of their variegation. Both feature pale green foliage stripped with a white outline, however in 'Avalanche' the pattern is white interior green edging with 'Overdam'  being the reverse of this. Of those in the garden 'Overdam' is the smallest with foliage being three feet in height and inflorescence reaching five feet. Like the others flowering takes place late in the summer with the inflorescence emerging a pale green  later ripping into deep reddish tones that border purple maturing to tan in the fall.Like the others the inflorescence can last all winter as long as the winter is not harsh. The inflorescence can make good cut flowers. This is our most recent acquisition (literally this past Monday). It was planted at the base of pear and the hope is it thrives there hiding the other mundane trunk and providing contrast to those plants that neighbor it. Being smaller it should be good for container gardens to. It also has a upright habit.
The Future
   The future is bright for this genus, it has proven in many including my own that these plants are tolerant of a wide range of conditions and can be used in a variety of ways. Many of these plants are upright in habit or small stature. Not just that but they prefer shady areas which many other grasses do not like , but Calamagrostis thrive in.
    Future plans with this genus involve further additions especially in one the garden of my grandmother. She has several pine trees , underneath them the plan is to add several native species of Calamagrostis and test those ones out. Many of the native species thrive in these conditions and in nature can be found living in  woodlands and there associated grassland glades.