Chapter 5. Ornamental Grasses For The Rock Or Marsh Garden

It is scarcely possible to overestimate the decorative qualities of ornamental grasses, both as marsh plants and for providing variety in the rock garden. Some are exceedingly graceful, others remarkably neat and compact in growth; there are some, again, very curious in form; while others are stately and majestic in appearance. The graceful and curious are best suited for planting in the wild garden, while the neat, compact-growing kinds make beautiful subjects for the rock garden.

By the side of streams and ponds the larger-growing species make handsome specimens.

In spite of the utility, and the ease with which most of them may be grown, ornamental grasses are not used in gardens to anything like the extent that they should be. All the species may be gathered and dried for winter decoration.

Tall-Growing Grasses

First let us consider those splendid importations from the River Plate, Cortaderia argentea, C. a. elegans, and C. conspicua (syn. Arundo con-spicua), the Pampas-grass. In severe winters these should have some dry, strawy litter thrown over them, and a few spruce boughs or evergreen shrubs stuck round to prevent the litter blowing away. The pampas-grass resists the cold of our ordinary seasons, but in many instances succumbs to the severity of an unusually cold and wet winter. Old plants seem hardier than young ones, arising probably from the larger top affording a more efficient protection to the roots. The old leaves should not be removed until the end of April, as they give the best possible protection as far as it goes; experience, however, shows that of themselves they will not always provide sufficient protection in our climate: hence the necessity of a little extra litter.

This is decidedly the king of all the grasses, and deserves a place in every garden. As the centre group of a grassery, or placed in a shady dell, near rocks or water, it finds a congenial home. A rich alluvial soil, at least a yard deep, abundance of space to unfold its large, graceful leaves and throw up its flower-stems, an unlimited supply of water, and shelter from strong winds, are all the conditions its successful culture demands. It can be raised from seed, and with liberal treatment, seedlings will flower in their third or fourth year. By sowing thinly in February or March in pots, and planting out in prepared beds in May, almost a season may be gained in the growth of the plants.

Like all the grasses, the seed should be barely covered with soil, and the surface kept moist, until germination is assured. There are, however, several varieties of this grass, in addition to its sexual distinctions. When practicable it is, therefore, best to purchase plants divided from those that have grown the finest flower-stems; the pampas-grass can be rapidly increased by division. Plants thus divided are more tender than others, and will require more protection until they are thoroughly established. Few plants, however, are more worthy of attention, as they have a fine appearance when growing; and if the flower-stem is cut before it begins to fade, it is almost as showy when dried. In addition to the localities here pointed out for them, they also contrast admirably with large masses of yews or other dark-foliaged shrubs.

A companion grass to this, with broad-striped foliage and large, feathery flowers, is the Erianthus Ravennce, the Woolly Beard Grass, growing to four or more feet in height. Other tall-growing grasses are: Arundo Donax and A. conspicua (syn. Cortaderia conspicua), which much resemble Pampas-grass; and a beautiful, little-known kind, Glyceria aquatica variegata.

The Tussock Grass and some of the common reeds and rushes also form beautiful features when used in connection with these.

Annual Grasses

Among the annual grasses we have eight or ten varieties of the Holcus saccharatus, or Sugar-cane, whose elegant leaves, stately stems, and variously-coloured heads of corn are highly ornamental. These are half-hardy annuals, and should be sown in gentle heat, being pushed rapidly forward so as to secure strong plants for planting out in May. The variegated, white-striped, and beautifully marbled Zea, or maize, requires similar treatment, and has a most pleasing effect when planted among other subjects. The pretty Millet Grass, Milium effusum, charming Love Grasses (Eragrostis multiflora syn. megastachya, E. papposa, and E. JEgyptiaca), and the several varieties of Briza, or Quaking Grass, especially Briza geniculata and B. minor var. gracilis, should be sown either in pots or in a rather sheltered site out of doors.

Other beautiful annual grasses are Agrostis capillaris, A. elegans, A. laxiflora, A. pulchella, Desmazeria sicula (syn. Brizopyrum siculum), whose branches rival in beauty the deciduous cypress, Bromus briziformis, B. lanuginosus, and Lagurus ovatus, the Hare's Tail Grass. Stipa arundinacea and Panicum Teneriffce (syn. Tricholcena rosed) are also useful, and, like all other annual grasses, should be raised from seed sown in spring. As a general rule far too little use is made of the delightful annual species.

Ornamental Grasses For The Rock Garden Perennials And Biennials

The various Eulalias (Miscanthus), the two Feather Grasses, Stipa pennata and S. gigantea, hardy perennials, and the hardy biennial Hordeum jubatum, or Crested Barley Grass, are also most useful for mixing with other flowers, and very elegant in themselves. The smallest Feather Grass almost rivals the Festuca glauca for edgings. The handsome silver foliage of the Festuca contrasts beautifully with red gravel paths, and is said to harbour fewer pests than any other living edging. It is neat, graceful, and easily kept. The only attention required being to cut off the flower-stems in summer; this should not be neglected as the cutting off of the flower-stems maintains the leaves in health and beauty.

Culture Of Grasses

Annuals. The hardy annuals are best sown where they have to grow, the seed being put in in April, or in May in colder localities. Except in cold, damp soils and in exposed districts, most hardy annuals are all the better if treated as biennials and sown where they are to grow in July or August. Half-hardy annuals are sown under glass in a temperature of from 60 to 70F., hardened off in May, and planted out in June; or they can be sown where they are to grow about the middle of May.

Perennials. Hardy perennials are sown in a nursery bed of fine soil in the open in May and June, and are transplanted to their permanent positions in October; half-hardy species being sown under glass in March to be planted out in the open in the next October. All grasses sown where they are to grow must be thinned when from two to three inches high, if bushy plants are to result. Almost all species thrive in good, well-drained loam, in a sunny, open position. In cold, damp situations it is frequently necessary to treat many of the perennials as annuals and to raise fresh plants each year. Perennial grasses are also propagated by division of roots either in April or October, at which times they should also be planted, if moved, from one part of the garden to another.

Cutting And Drying For Winter Use

Apart from their beauty as rock, marsh, and wild garden plants, many ornamental grasses, when correctly dried, can be used effectively to fill the flower vases, or at least to supplement the cut flowers during the period of shortage of blooms through the winter months. They must, however, be cut at the right time, usually between June and the end of August.

In cutting, which must be done before the heads are fully out, and while the grass is still green, the stalks should be kept as long as possible. The grasses should be tied up in bunches and dried in a cool, airy place. Gathering must take place in fine weather and when the grass is quite dry.

Are You Ready To Move Onto The Next Lesson? Click Here...