EVALUATION OF GROWING AND FLOWERING OF FIVE SPECIES OF ORNAMENTAL GRASSES IN THE REGION OF LUBLIN

The great decorative diversity (shape and size of infl orescences, colouring and texture of leaves, varied intensity of growth) as well as big tolerance to habitat conditions, relatively small susceptibility to diseases and small sensitivity to ‘ornamental grasses’ pests favour their popularization in different gardens and urban areas. The examined species all may be recommended to plant in cooler east regions of Poland. Species which begin the earliest vegetation and fl owering were Calamagrostis x acutifl ora ‘Karl Foerster’ and Deschamsia caespitosa ‘Goldtau’. These species, best planted separately or in small groups, can be also recommended in small garden compositions. For large areas, naturalistic gardens as well as structural plants of fl owerbeds the best are Calamagrostis x acutifl ora ‘Karl Foerster’, Deschampsia caespitosa ‘Goldtau’ and Miscanthus saccharifl orus ‘Robusta’. Phalaris arundinacea L. is a typical ground covering grass with decorative leaves.


INTRODUCTION
Perennials are a popular decorative component of gardens.Apart from the best known genera as Peonia, Phlox or Aster, plants until recently forgotten and less known are regaining their popularity.They include 'ornamental grasses', also called 'bedfl owers'.Nowadays, they are being gradually introduced into gardens and other green areas.It is an interesting group of plants due to their characteristic architecture, varied shape of infl orescences as well as colours and texture of leaves (U rb a ń s k i , 2001).Thanks to their lightness and susceptibility to the smallest move of the air, they bring a new dynamic element to garden compositions.Grasses come from different parts of the world so that they grow in a great variety of habitats (M i z i a n t y , 1995; F r e y , 1997) thus it is possible to choose plenty of species and varieties which are suitable for water gardens, poor sites or urban areas (F a l k o w s k i , 1982; H a b e r , 1989).The knowledge concerning their morphological features and habitat requirements is essential to decorate different types of gardens with 'ornamental grasses'.
The purpose of the studies was to evaluate growth and fl owering of the species of 'ornamental grasses'.The research dealt with morphological characteristics -the clump diameters, the number of vegetative and generative culms -species and cultivars evaluated during the successive seasons.Aesthetic attributes were analysed as well.Changes in their scales during one vegetative seasons as well as in the course of successive years of cultivation have a signifi cant impact on small compositions or a whole garden.Whithin this group of plants there are species and varieties which surpass others due to their invasive habits.On the other hand, this group of plants includes such grasses which hardly change their "living space".Consequently, it is vital to learn morphological features of these species which are becoming more and more commercially popular.

MATERIALS AND METHODS
The experimental material were species and cultivars as follows: Calamagrostis x acutifl ora 'Karl Foerster' (H a b e r , 1989), Deschampsia caespitosa 'Goldtau', Miscanthus saccharifl orus 'Robustus', Muehlenbergia mexicana (L.) Trin.(U r b a ń s k i , 2001), Phalaris arundinacea L. The plants came from the collection of ornamental grasses of the Institute of Ornamental Plants and Landscape Architecture of University of Life Science in Lublin.The experiment was set up in fl at area on a sunny site in autumn 2003.Young clusters with the diameter 8-10 cm were planted in the plot 150 cm wide, in spacing of 35 x 50 cm.They were protected with a light layer of composted bark against winter weather.The grey and brown podzolic soil made of loess on chalky marls with pH 6.5 constituted the ground.The observations conducted in the years 2004 and 2005, which means in the fi rst and second vegetative season of investigated species, started on the 30 th of April and were continued till the end of September.On the 30 th of July 2004 and 2005 soil samples were taken for analyses from the plots where the grasses were grown.The content of available nutrients in the successive years were as follows: the year 2004 -N-NO 3 -20, P-50, K-120, Ca-600 and Mg-35 mg in 1 dcm -3 of soil, the year 2005 -N-NO 3 -31, P-60, K-170, Ca-500 and Mg-40 mg in 1 dcm -3 of soil.In June and July•the clumps were radically treated with 0,1% multicomponent dissolved liquid fertilizer INSOL U. Observations and measurements were conducted taking into consideration ten plants of each species and cultivars.The systematical measurements dealt with the height of the clustery -the measurement was made from the base of a plant to the end of leaves in their natural position; the number of vegetative culms and peduncles in one cluster; the length of peduncles and infl orescences.The diameter of each clump was measured in its widest place.Not only the term of the beginning and ending of fl owering was noted down but the period of the most stunning beauty appeal of the investigated species and varieties.In the Spring 2004 frost resistance of the plants was assessed.The experiment was meant with 10 repetitions where one repetition dealt with one plant (one clump).The results of research were verifi ed by using variance methods.The differences between means were evaluated by applying the Tukey test at p=0.05.
During two periods: the middle of July and August beauty attributes of the grass species and cultivars under discussion were examined by three experts.The 5 stage scale was used to appreciate the plants.A species characterised by the best qualities reached the top in the rank by scoring 5 points.The features which were taken into consideration while estimating decorative values of the ornamental grasses were as follows: the architecture of plant, the colour of culms and leave blades, the size and colour of infl orescences as well as the duration of their remaining on a single plant.

RESULTS AND DISCUSSION
The main beauty attributes typical of 'ornamental grasses' are their shapes, sizes and ranges of colours of vegetative and generative peduncles (C l a y t o n and R e n v o i z e , 1986).Most of the species, especially medium and tall height provide a very strong vertical accent to any garden thanks to their stiff parallel or arched vegetative peduncles growing from dense clumps and supporting infl orescences.Culms are encircled with long linear leaves which gently hang down, form sharp folds in top parts or almost horizontally stick out from a clump (U r b a ń s k i , 1997; L e y h e , 2007).A lot of species of 'ornamental grasses' are highly frost resistant, however young grasses planted in autumn ought to be protected against severe winter temperatures (U rb a ń s k i , 2001).In the Lublin region winter 2003/2004 was typical of this area.The average monthly air temperatures were not higher then in the previous years (means monthly air temperatures were: in November 2003: 1.3 o C, in December 2003: 1.3 o C, in January 2004: -5.6 o C, in February 2004: -1 o C and in March 2004: 2.8 o C) so that snow layer in January and February provided a natural protection for the grasses planted in autumn.All specimen of examined plants were not affected by winter and started their vegetation in early spring.In the third decade of April three species started to grow: Calamagrostis x acutifl ora 'Karl Foerster', Deschampsia caespitosa 'Goldtau' and Phalaris arundinacea.Muehlenbergia mexicana began its growth ten days later followed by Miscanthus saccharifl orus 'Robustus' at the end of May (Tab.1).The examined species and varieties were characterised by dynamic growth of their vegetative parts at the beginning of vegetation, however these qualities differ distinctively as for as each species is separately concerned.The intensive growth of Deschampsia caespitosa 'Goldtau' and Calamagrostis x acutifl ora 'Karl Foerster' was observed from the 1 st decade of May till the 1 st decade of June, whereas Muhlenbergia mexicana was growing luxuriantly from the 1 st decade of May till the end of June.The lush growth of the surface part Phalaris arundinacea occurred from the middle of May until the middle of August.Miscanthus saccharifl orus showed the similar progress.The rate of growth of the fl owering grasses slowed down shortly before their blooming.
The experiment reveals that Deschampsia caespitosa 'Goldtau', Muehlenbergia mexicana and Phalaris arundinacea, before infl orescences appearing, in the fi rst year after being planted, reached the height 48, 68 and 60 cm respectively.Next year they became higher: 66, 70 and 84 cm (Tab.2).The heighest 'ornamental grass' was Miscanthus saccharifl orus 'Robustus' reaching over 150 cm.The second grass while considering its height, was Calamagrostis x acutifl ora 'Karl Foerster', which in 2005 grew to 110 cm before fl owering.Apart from height, while designing a fl owerbed, the plant diameter is of signifi cant importance (L e y h e , 2007; U r b a ń s k i , 2001).This feature can change during a few successive vegetative seasons.According to the observations the species which chanced the size of its clump at the least dynamic rate throughout two years was Calamagrostis x acutifl ora 'Karl Foerster'.In spite of a large number of linear vegetative culms (379-408) this grass was characterised by a dense clump whose diameter was up to 54 cm in the fi rst year while in the second year it was up to 64 cm.The soaring shape of Calamagrostis x acutifl ora 'Karl Foerster' was also enhanced by a vertical, parallel arrangement of penducles reaching up to 190 cm.The clump produced Table 1 Term of beginning and ending of fl owering and period of decorative value of examined species and varieties of ornamental grasses.

Species and cultivars Years
Height Miscanthus saccharifl orus 'Robustus' is a high grass which reached almost 2 m during its fl owering season.The two year old clump consisted approximately of 135 vegetative peduncles with characteristic linear blades bending gently outside.The plant created huge vertical form which resembled 'fountaines' in their shapes.Its most stuming decorative features are soft, silky infl orescences set on stiff straight peduncles dominating high above the clump.Miscanthus saccharifl orus 'Robustus' produced 19 infl orescences in the fi rst year of the experiment while in the second one this number was doubled.Among the examined plants Miscanthus saccharifl orus bloomed as the last at the end of August and produced new peduncles till the middle of September (Tab.1).Phalaris arundinacea, the grass of middle height, is valued for its wide blades with the white strap along every leaf, which seems to be its most ornamental quality.This species expanded increasingly, so that in the second year of cultivation it produced 20% more vegetative culms than in the fi rst year (408-455 leaves).At the same time its tendency for lodging was observed during heavy rain falls.
Taking into consideration the decorative qualites observed in June Deschampsia caespitosa, Calamagrostis x acutifl ora 'Karl Foerster', Miscanthus saccharifl orus 'Robustus' and Phalaris arundinacea enjoyed the experts' highest appreciation (Tab.2).A great attention was paid to such characteristics as bright green foliage, the scale of the plants as well as a great number of light infl orescences created by Deschampsia caespitosa.Du-ring autumn all the grasses under discussion except for Phalaris arundinacea won the highest places in the rank -5 points.The plants investigated in this experiment due to their beauty appeal can enrich various garden compositions.Some of them like Miscanthus saccharifl orus or Deschampsia caespitosa 'Goldtau' create a strong visual accent in every park or garden (U r b a ń s k i , 1996,1997,2001).It is advisable to plant Miscanthus saccharifl orus 'Robustus' separately or in small groups in large spatial fl owerbeds or naturalistic gardens.Others species like soaring Calamagrostis x acutifl ora 'Karl Foerster', ethereal Deschampsia caespitosa 'Goldtau' or green and rust Muehlenbergia mexicana should be combined with perennials with large leaves and distinctive colours.Most the examined grasses change the size of their clumps signifi cantly in the course of the growing season.In addition, these grasses enlarge their size while blooming.These characteristics should not be neglected especially when they are meant to grow close to smaller species.The ornamental grasses investigated in this experiment throughout the whole vegetative season from the moment of full foliage development until the edn of fl owering not only create marvelous decorative forms but retain their characteristic shapes and forms.What is more, they enhance garden beauty even during winter.

Table 2
Morphological features of 'ornamental grasses' in the fi rst and second year of cultivation.Means with the same letter do not differ signifi cantly (Tukey test, p=0.05).Chosen morphological features of infl orescences of examined 'ornamental grasses' species in the fi rst and second year of cultivation.Muehlenbergia mexicana by 120% in comparison with the fi rst year.These two species also produced a large number of peduncles throughout their fl owering seasons.From the clump of Deschampsia caespitosa 122-128 (Tab.3) thin and stiff peduncles emerged.They were ended with large open wisps which formed huge bright sweeping clouds of fl owers above leaves.Muehlenbergia mexicana created 200-212 peduncles ended with wisps hanging off the outside of the clump, which were brown and cropper in autumn The most expansive species appeared to be Miscanthus saccharifl orus 'Robustus' and Phalaris arundinacea.The increase of clumps diameter in these plants over the course of cultivation in 2005 was doubled or even tripled in comparison to the fi rst year of experiment.
3. Grasses which demonstrate green leaves at the earliest time -the third decade of April -are Calamagrostis x acutifl ora 'Karl Foerster', Deschampsia caespitosa 'Goldtau' and Phalaris arundinacea.On the other hand, the leaves of Calamagrostis x acutifl ora 'Karl Foerster' and Miscanthus saccharifl orus change the range of their colours at the end of the vegetative season.4. Especially decorative infl orescences staying on single plant also during winter period are developed by Deschampsia caespitosa 'Goldtau', Miscanthus saccharifl orus 'Robustus' and Muehlenbergia mexicana.