Hardy Herbaceous Perennials

Date Published: 
August, 1902
Original Author: 
Robert Cameron
Original Publication: 
AACS Proceedings of the 16th Annual Convention

In a short paper like this it is manifestly impossible to do more than call attention to some of the best of the many useful and showy hardy herbaceous perennials that can be grown and used to ornament and give effect in cemetery plantations: Therefore, my object is to recommend and treat briefly, plants that bloom in early Spring and onwards until late Autumn; and also to show a few of the many ways in which they may be used to advantage.

Herbaceous perennials are plants having perennial roots, with tops that die down to the ground annually, such as Delphiniums, Peonies, Veronicas, grasses and ferns. There are many other species which have evergreen leaves and are usually placed under the above heading; such as some of the Pentstemons, Saxifrages, evergreen creeping Phlox, Sempervivums, and some Sedums.

Hardy herbaceous perennials are exceedingly important in landscape work, and although many of our landscape artists do not give them the same rank in importance that they do to hardy trees and shrubs, nevertheless, some of them ask us to imitate nature, and if we do, we find she always gives us a generous supply of herbaceous perennials well intermixed with the trees and shrubs. Probably the actual reason why they do not stand as high in their estimation as trees and shrubs is that this class of hardy plants are not so numerous that it requires more careful selection than any other class to do effective work with them. Anyone who knows a Phlox, a Peony, a Larkspur, an Oriental Poppy, a Japan Iris or Japan Anemone will admit that many perennials are very beautiful, but they will also admit that there are many which are not so showy and useful for ornamental purposes. Consequently, a person has to have a good knowledge of this kind .of plants to get the best results. He not only requires to know the height, the habit and the color of the flowers of the plants, but he also ought to have good taste in arranging the various plants so that the flowers which are in bloom at any given time shall group well in form and color. It also requires study and forethought to get the best and most suitable plants for the different seasons.
One of the most common ways of growing herbaceous perennials is in the mixed border. The first step to take in making a border of this kind is to select a suitable location. There are many fitting locations to be found in cemeteries, such as alongside a drive, a fence, a walk, an avenue, the foreground of shrubbery beds, or at the foot of a stone wall. There is one precaution that ought to be taken when selecting a location that is if possible, not to place the border near large trees, as the roots of the trees will deprive the perennials of their nourishment.

The outline of the border is not important; it may be straight, curved or irregular, according to the situation.

After selecting the location, the next consideration is the soil. If of moderate depth any kind of' soil will grow the plants, provided that plenty of manure is given; but a deep loam if well trenched of medium texture that does not need an annual supply of manure is the best. Of course, all have not such a soil at their command, and therefore recourse must be had to supplying the most suitable ingredients to the varying soils that have to be dealt with. A deep loam if well trenched and given a good dressing of well rotted manure will need little if any other dressing for three or four years. This is of great importance both as regards saving of labor and well doing of the plants, as many kinds of herbaceous perennials will attain their most perfect development when left undisturbed for years. Clay soils should be trenched at least two feet deep and plenty of leaf soil worked in with the manure.

The arrangement of the plants in their order is a matter of taste but here I would advise the grouping style, which consists of planting a number of plants in a mass, the aim being to obtain color in such quantity as to prove effective when seen from a distance. The taller growing kinds should be arranged at the back and the dwarf kinds confined to the front of the border, but a too strict line of uniformity of height should be scrupulously avoided and pains should be taken to dispose of the plants as to color so that there shall be no violent or jarring contrasts. The time of flowering of the different kinds should be thought of so that there may, be throughout the season a regular dispersion of bloom over the entire border. The best example I have ever seen of this grouping style was last year at Drummond Castle, Perth shire, Scotland. Indeed, it was a surprise to me.

Every fourth year we dig all the plants from our herbaceous borders and trench the ground. In this process of trenching, the earth is completely turned over, to the depth of two feet and we work into the soil a liberal supply of well rotted cow manure. In turning over the soil to this depth it gives an opportunity to remove all roots and weeds from the soil. Not only does the soil need enriching, but there are many of the strong growing kinds of herbaceous plants that need lifting and breaking up the plants degenerate, the growth becomes weak, the flowers small and few in number. Examples of such are Phloxes, Delphiniums, Asters, Rudbeckias and Chrysanthemums. When overhauling the border in this way there are many plants that require just as careful handling as if removing a large tree. The plants are very sensitive to rough handling and if it is not done with care they do not grow or flower as well for some time afterwards. Examples of such plants are Adonis Vernalis, Statice latifolia. Clematis recta if not lifted and planted with care does not grow more than eighteen inches the first season when it ought to grow four feet. The best time to do this kind of work is early in September; the nights begin to get cool then, we are liable to get showers, and the soil has not lost any of its warmth, and the plants are able to make new roots and growth before winter sets in.

During July and August there is always a scarcity of bloom in the mixed herbaceous border and there are many places that need filling up, as some of the plants that bloom in the early Spring die down, such as Oriental Poppies and all early flowering bulbs. The empty spaces which these plants leave are not pleasing and can be filled with such good annuals as Zinnias, Tagetes, Asters, Stocks, Phlox Drummondi and many others which give a profusion of bloom during the summer months.

The only care the borders need during the summer months is keeping the ground clear of weeds, cutting dead leaves and stems, and tying up such kinds as need support. A few words on tying and staking will not be out of place here. A plant should not be tied that is at all likely to be self supporting. The height of the stakes never ought to exceed the height of the plants and the ties should not be drawn so tightly that the plants present a broom-like appearance. In dry weather the strong growing kinds need a liberal supply of water.

There is an endless supply of hardy plants that can be used in the herbaceous border, but I will only mention twenty-five of the best Spring and early Summer flowering kinds, and twenty-five of the best late Summer and Autumn flowering kinds. For the early kinds, the following are exceedingly good perennials: Alyssum saxatile with its golden yellow flowers; Aquilegias, several species, caerulea, glandulosa, Stuarti and Chrysantha being the best; Arabis albida, Phlox procumbens, P. Subulata and its varieties are showy dwarf plants; Polemonium reptans and caerulea are good for blue colors; Stellaria HoJostea has numerous white star shaped flowers; Veronicas many kinds, the choicest being rupestris, gentianoides, incana, paniculata and latifolia; Pentstemons which are hardy and reliable are P. digitalis, diffusus, oratus, barbatus, barbatus var, Torreyi, and pubescens; Pyrethrum roseum, very fine, has many forms both double and single, the single flowers are very pleasing ; Clematis recta has panicles of beautiful white flowers; Dianthus barbatus and many other species are good; Campanula carpathica makes tufts of blue; Delphiniums, many kinds and all are exceptionally showy plants; Dicentra spectabilis or bleeding heart is one of the most graceful hardy plants we have in early Summer; Orobus vernus fine early dwarf pea flowered plant; Lychnis chalcedonica and Viscaria flowering plants are both good; Primula veris and vulgaris and their varieties are well known; Campanula persicifolia and its white flowered variety are of medium height bell flowers; Paeonias herbaceous kinds are all beautiful; Papaver orientale and its varieties are without doubt the showiest of hardy plants; German Irises are good border plants and will flourish in almost any situation; Iris laevigata from Japan is extra fine for late Slimmer but requires more moisture than the German Irises. Geranium sanguinea is about a foot in height and has a profusion of red flowers; Baptisia australis gives good racemes of blue flowers in June; Erigeron speciosum and Aster alpinus are the two best early compositae we have.

For late flowering kinds the following are good: Aconitum autumnale; Anemone Japonica and its varieties; the best Asters for border use are Novae-Angliae and its varieties. Aster turbinellus and Aster Shortii, Bocconia cordata, Boltonia Jatisquama are tall, showy plants; Platycodon grandiflorum is a grand perennial and flowers for several months; Coreopsis grandiflora, Dictamnus fraxinella and Gaillardia grandiflora are choice perennials; Helianthus mollis, Helenium autumnale and Hoopesii are good plants for the back row in the border; Monarda didyma is the best of the horse mints; Pyrethrum uliginosum when well grown is very showy; the best of the Rudbeckias are speciosa, sub-tornentosa, and golden glow; Scabiosa caucasica is the finest of all the species of Scabios ; Statice latifolia is the best of the sea lavenders; Veronica subsessilis is very choice; Sedum spectabile is the handsomest of the Stonecrops; Oenothera Missouriensis has the largest flowers of all the evening primroses; Eryngium amethystinum has roundish heads of flowers with a very striking blue color; the best of the day lilies are Hemerocallis flava, dumortierii and fulva. To these might be added foxgloves, Hollyhocks and the late flowering Phloxes.

Some of the best bulbous plants for the borders are Allium moly; Bulbocodium vernum, Camassia esculentum; and C. Fraseri; the different species and varieties of Crocus; Erythroniums, Frittilarias, Snowdrops, Hyacinths, Lilies, Grape Hyacinths; Narcissus many species and varieties, Puschkinia, scilloides, Scillasiberica and Campanulata, Tulips; the species are showy and some of them, such as T. gesneriana, T. cornuta and best of all is T. Greigi. It is not only well to know what to plant, but sometimes it is well to know also the plants that are not desirable for border culture. Some of the plants are recommended in catalogues, but if they once get into the border they are constantly a source of trouble and expense. They spread so rapidly that they kill the weaker plants which grow near them. The most troublesome of these are: Achillea serrata, the variegated aegopodium podogravia, Anemone Pennsylvanica, Saponaria officinalis, Stachys palustris and Heliopsis laevis.

In many cemeteries there are ideal spots for rock gardens where a host of herbaceous plants can be grown. In rock gardens tender greenhouse plants are out of place. Although there are many alpine plants that we cannot grow in our climate, we have plenty of herbaceous and bulbous plants to use. When the suitable location is found there are few more interesting features of out of door gardening than this, and in early Spring and at Memorial Day there would be no spot of the cemetery as pleasing as the Rock Garden.

The herbaceous border and the rock garden are not the only places where hardy perennials can be used with good effect. Some of them are beautiful when naturalized in different parts of the grounds. Many of the spring flowering bulbs do admirably planted in the grass that is if the grass is not cut before the foliage of the bulb withers. Narcissus poeticus is especially fine when grown in this way. At Prof. Sargent's place in Brookline, Mass., it is grown beautifully in this way and is a magnificent sight when in bloom. Bulbs such as Crocuses and Scillas that are planted in places where the grass has to be cut before the foliage of the bulbs mature, have generally to be planted every year. This ought not he an objection to those beautiful bulbs, as they are so very cheap now. The tall summer and autumn flowering compo sitae such as Heleniums, Rudbeckias, Helianthuses, Silphiums, Asters and Golden Rods make a splendid showing when planted amongst shrubbery. Lilies are at their best when planted in Rhododendron beds. Along water margins there are many plants which lend themselves very pleasingly and give excellent effects. Such are Iris, Cardinal flowers, Lythrums and many kinds of grasses. I recollect a tasteless arrangement I saw in a cemetery, a large pond encircled with a double row of Salvia Splendens,

Another use for which the large growing perennials are admirably adapted is to produce subtropical effects. There are quite a few plants that can be used in this way; for example, Helianthuses, Silphiums, Bocconias, Arundo donax, Eulalia Japonica and its varieties, Aralias, Acanthuses, Polygonums, Rheums, Heracleums, Centaureas, Eryngiums and Echinops.

There are many hardy and half hardy perennials which make showy and attractive beds on the lawn. Silene pendula and the forget-me-nots, which are grown as annuals, make excellent beds for early spring. Phlox procumbens, P. subulata and P. reptans are also good for early work. Stellaria Holostea is very good for white. The dwarf Veronicas are all good in early Summer. The tall growing Phloxes, Paeonias, Irises and the tall, graceful grasses all lend themselves readily to this kind of work.

There are many inquiries as to what perennials will grow under trees. I have found the following very satisfactory: Vancouveria hexandra, all kinds of Funkias, Pachysandras, Hepaticas, Asarum Europaeum, Ajuga, Reptans; Orobus Vernus, Lilly-of-the-Valley and many kinds of ferns. The propagation is either by seed cuttings or division of the plants. Every cemetery ought to have a small nursery and grow its plants instead of buying them. Plants are easily raised from seed and can be raised in quantity.

The winter protection of herbaceous perennials is important. Plants that are not reliably hardy can be protected with any material which is not too moist or dose. Most of the perennial plants that are in ordinary cultivation need no protection, but in the Eastern States we find that a coating of some material that keeps them from excessive freezing and thawing during the winter is very beneficial to the plants. If barn yard manure is used a double advantage is obtained, the plants are kept in good condition, and from the leachings during the winter they obtain food. Leaves of deciduous trees, pine leaves and hay are all good for protection. The dressing for protection should not be applied until the ground is well frozen; that will be about the first of December. The covering need not be very thick-two or three inches is enough. The covering is not intended to keep out the frost so much as to prevent alternate freezing and thawing by which the plants are thrown out of the ground, the roots broken and exposed to the sun and air. If the ground keeps frozen all winter this trouble is avoided. The covering should be removed as soon 'as the weather will permit in the spring.

A short time ago I made a tour through the different cemeteries and graveyards around Boston to see what was used in the way of herbaceous perennials. I was disappointed to see the small number used. I do not want to run down the tender bedding plants, as there is plenty of room in our large cemeteries for all kinds of plants, from the American Elm and the tropical palms down to the Alpine Drabas not more than an inch in height. What I do want to point out is that the man who has not the greenhouses to raise the tender plants need not be discouraged, for he has ample material to select from amongst deciduous trees, evergreen trees, shrubbery of all kinds, and herbaceous perennials. The species and varieties of tender bedding plants are few in number compared with the hundreds of hardy perennials that a person is able to select from. There are no bedding plants that will compare with Irises, larkspurs, daffodils, lilies and many others. It is so monotonous in our cemeteries. Almost wherever you go in them you find Geraniums, Coleus, Salvias and Heliotrope. Another point in favor of the hardy plants is that long before the Geranium, Coleus, Heliotrope or Salvia have left their warm quarters in the greenhouses we have enjoyed the charming early Spring flowers such as Scillas, Snowdrops, Crocuses, Tulips, Hyacinths, Phlox, Arabis, Hepaticas and Violets. Not only have we the hardy plants in the early spring but also late in the fall when all our tender plants are housed.

From the publication:
AACS - Proceedings of the16th Annual Convention
Held at Boston, MA
August 19, 20, 21 and 22, 1902