The book of climbing plants and wall shrubs

Front matter

Class Book_

HANDBOOKS OF PRACTICAL GARDENING EDITED BY HARRY ROBERTS

THE BOOK OF CLIMBING PLANTS AND WALL SHRUBS

Contents

Editor's Note . . . . -

^ Introductory . . .

The Value and Beauty of Climbers — Cheapness of Some — Nature and Habits — Plants Included — Nomenclature.

Chapter I

The Value and Beauty of Climbers — Cheapness of Some — Nature and Habits — Plants Included — Nomenclature.

Apart altogether from the interest which attaches to their habit of growth and the processes and contrivances by which they attach themselves to their supports, climbing plants are entitled from their charms to the appreciation of all who admire the beauty of plants in their varied forms. Even our native climbers contribute largely to the charms of our landscapes by the manner in which they clamber over trees, hedgerows and rocks, and none of us can see unmoved by admiration the wild Roses which climb among our hedgerows, the fragrant Honeysuckle which adornsmany a scene, or the Traveller's Joy covering as with a cloud of foliage and flowers some quiet or unfrequented spot. Nor can we be unappreciative of the part played by the Ivy in the adornment of our ancient buildings, which owe much of their attraction in many cases to the veil of green which covers up their architectural or structural defects, and makes them assume perfect beauty in our eyes. In their own way these supply to our landscape the effects of the climbing plants of the tropics, though, as befits our greyer atmosphere and quieter landscapes, they are, it may be, less brilliant in their colouring than the showy flowers which cover

a 1 the bushes or clamber up the trees of brighter lands. These tropical plants are with us the inmates of our greenhouses and stoves, and it is under glass that we can see their beauties and enjoy their delights. From more temperate climes, however, we can draw the climbing plants which will decorate our gardens and our walls, and which are as hardy, or nearly so, as our native plants which we can see in the woods and lanes of the country side.

It seems unnecessary to speak at length of the value of the climbing plants in our gardens and pleasure grounds. They are equally ornamental on the walls and terraces of the stately mansion, and on the humblest cottage, over whose low roof a mantle of Rose or Clematis sheds such a transforming cloud of beauty. They grace the garden walls, and take from stiff and hard lines their ugliness by fresh foliage, pretty flowers, and often pleasing fruit. The trellis may be draped with them. Over the garden paths they may depend from the archways, or the pergola may be their resting-place with its cloistered aisles overhung and shaded from the strong sunshine by their green leaves, which often look so lovely between one and the light, and decked by the blooms dangling from pliant stems or in clouds up the pillars. Then the arbour is both shaded and beautified by these plants, and they may be more widely used than they have been to give variety to the wilder parts of the grounds. A glen or a stream side may have its beauties heightened by planting alongside the native shrubs and trees some of the exotic climbers, which give grace and brightness and form a charming feature.

Then, too, what is a greenhouse, a stove, or a conservatory without a climber about it, to cover its walls, hang from the rafters or roof, or cover its bare pillars ? It is a poor greenhouse indeed, which has not room for at least one of these plants, even if it is impossible to use the Grape Vine with its beautiful leaves and its succeeding luscious fruit. In the pages which follow there is named a wealth of choice climbing plants for all such buildings ; some are slender and graceful, while others produce huge, ornamental leaves and flowers more suitable for the great winter garden or conservatory than for the modest greenhouse of the amateur, who can draw from among the smaller-flowered or weakergrowing genera something to suit his purpose.

Nor is it necessary in growing climbing plants either in the open or under glass, to expend much money in securing their beautiful effects. How much may be done with a packet of common " Nasturtiums " as we familiarly call the varieties of Tropaeolum majus ! How much will eventually be covered by a plant of a pretty Ivy, costing only a few pence, or a graceful Clematis, which can be had for eighteenpence or less ! The wealthy amateur who can afford to expend a large sum ought to purchase a large number of the choicest climbers and wall shrubs, but none who have gardens need be or ought to be without as many as possible of these valuable plants, whose worth for decorative purposes can hardly be overpraised.

The study of the nature and habits of climbers is a most interesting one, upon which a vast amount of light has been thrown by the researches and experiments of Charles Darwin, De Vries, and others. Naturally, in a work of this size, it is impossible to enter into such questions in detail, and those who wish to study the subject will do well to peruse carefully such works as Darwin's " Movements and Habits of Climbing Plants " (London, John Murray), where they will find much to interest and also much which will help them in cultivating these plants.

The development of the climbing habit appears to be due to the pressure of circumstances and the desire of nature to economise. The climber has generally to find its way to the light and air by aid of the support of other plants or surrounding objects of greater height, and had it not its lengthened stem and its climbing powers it would be strangled or destroyed by want of light and by being unable to absorb the carbon dioxide it requires. The elongation of the stem without additional thickness would have been insufficient from its want of power to sustain itself erect, and thus the powers of twining round or clinging to something which would support it were developed to aid in the struggle for existence. These powers are provided in the shape of a twining habit, tendrils, aerial roots, prickles, or hooks. Some writers are disposed to separate twiners from other plants with a climbing habit, but for gardening purposes they ought to be dealt with together. The contrivances by which these plants attain to the light and support their stems are varied in their character, and, though they might be divided broadly into a few classes, yet there will in a few cases be found some which possess a share of two or more means of climbing or supporting themselves and cannot therefore be classed with only one section. Yet they may generally be divided into twiners, tendril-bearers and leaf-twisters, aerial rooters, and those which support themselves by prickles or hooks or by simply scrambling among other and stiffer plants to reach the light. The Convolvulus is a familiar example of the twiner, while the tendrilbearing class may be represented by the Vine or the Pea. The Ivy is a good representative of the aerialrooters, and in the Blackberry and the climbing Rose we have representatives of the plants which support themselves by means of their prickles. Darwin looks upon the tendril bearers as more highly developed than the simple twiners, and it is interesting to observe in these the way in which the spiral form assumed by the tendril makes, as it were, a spring by which the strain is relieved when the climber or its host is exposed to gales which might tear them apart.

Even more fascinating is the study of the movements of the climbers in search of support. Some of the twiners revolve with, and some against the sun ; some seek the light, and others shun it, so as to cling to something in the shade. Yet almost all have a revolving motion when in search of something to lay hold of. They sweep with regular motion the limited space they can reach and are thus afforded opportunities of reaching a support they could not have touched were they devoid of this power. Darwin has given much information on these points, and all growers of climbing plants would derive pleasure and profit were they to study his work carefully. From a purely gardening point of view one conclusion of the eminent scientist deserves attention. That was that some climbers upon which he experimented required to be well cultivated and placed under favourable conditions of all kinds in order to attain the full development of their climbing powers. This is an observation of some importance, showing as it does, that much of the non-success of some climbing plants in gardens is due to want of satisfactory conditions in the way of soil exposure, or of a suitable medium to which to attach themselves.

In this connection it must also be observed that some people err in thinking that all climbers will grow against similar objects, while Darwin's experiments prove that even different species of the same genus required supports of different thickness to meet their wants.

Besides the true climbers, twiners, and scandent plants which are cultivated in gardens as "climbing plants," popular usage has frequently classed with them in conversation a number of plants which are devoid of any climbing propensities, but which are largely used for covering walls and other objects to which they can be attached by nails or other means of support. It has been thought advisable to include these plants, so as to make this volume as useful as possible.

On the other hand, some dwarf twining plants of little use for climbing and only serviceable in the garden for furnishing hanging baskets and such purposes, have been omitted.

In the preparation of this volume it has been my desire to include not only the climbing plants and wall shrubs commonly met with in private gardens, which almost everyone knows, but also a few which are rarely to be seen except in botanic gardens. Their presence in a garden would help to render it more interesting alike to its owner and his friends, and many of these plants, from their intrinsic beauty, are of the highest worth. Of course, a great number have been omitted which would have been included but for the necessity of keeping this work within moderate bounds. With the same object in view a large selection of climbers has been given in tabular form at the end of the volume, with information regarding their colour, the temperature they require, and the time at which they bloom. In some cases these are not mentioned in the chapters containing the general remarks for the corresponding classes, and in these instances it is to be understood that they are amenable to the ordinary treatment recommended in the chapter on soil, etc.

The cultural directions, though necessarily brief, will supply as much information as is absolutely necessary for those possessed of a little knowledge of the principles and practice of plant cultivation. These will understand the necessity of varying the treatment under diverse circumstances.

The nomenclature is generally that of the Index Kewensis and the Kew Hand-lists, though these have not been always followed in some cases where the garden names are too firmly fixed to be readily superseded.

Chapter II Soil, Planting, After-management And Propagation

Errors in Planting— Preparing Station — Soil — Manures — Planting — Feeding — Shade — Pruning and Training — Supports — Enemies and Remedies — Under Glass — Propagation.

It is much to be regretted that, as a rule, the requirements of climbing plants are but imperfectly considered in gardens.

They are often planted, with the most meagre preparation, in poor soil, either composed largely of the rubbish filled in after the building of the house, or that which has been impoverished by other plants. In either case it is hopeless to expect the free and luxuriant growth which constitutes one of the beauties of such plants. On the contrary, they are often stunted and unhealthy in appearance from neglect in these and other ways. Nothing is more common than to see them turned out of small pots into a hole little larger than the pots they have occupied, and without any preparation having been made for the extension necessary for the roots if the climber is ever to become healthy, vigorous and beautiful. Even where a little attempt is made to secure this it is often absurdly inadequate, and the roots are checked by the mass of hard, poor soil with which they eventually come in contact. It is better to make too much preparation than too little, and when planting climbers in the open to make a large and deep hole from three to six feet across and about three feet deep, filling it up with good loam, with the addition of some manure, some of which ought to be well worked into the subsoil.

There is nothing better than a good sound loam for the growth of the greater number of climbing plants, and unless advised otherwise, this, with the addition of manure, should form the basis of the compost. As a general rule, there is no fertiliser which equals thoroughly rotted animal manure, that from the cow-house being the best for light, dry soils, and that from the stable the most beneficial for those of a heavy nature. In stiff soils some leaf-mould and peat are often beneficial. Artificial manures may be used, where the others are not available, in the proportions recommended on the packages of those of a proprietary nature, which are generally the safest to be used by amateurs, A considerable proportion of bone meal is also desirable and supplies the permanent nourishment wanting in some of the artificials.

If the climbers have been growing in pots they may be planted out at almost any season, but others may be planted either in autumn or spring, the former being the best season for districts where drying winds prevail at the latter season. In case of severe frosts they should be slightly protected for the first winter.

In planting, those which have been grown in pots ought to be turned out carefully with the ball of soil intact, except that the roots may be spread out, so far as this can be done without removing all the soil from the ball. The others should have the roots carefully spread out at their full length and not crushed or crowded in any manner. Any injured roots ought to be carefully cut with a sharp knife, removing the bruised portions. After planting, the soil, which should not be too wet, must be firmly trodden or pressed down and the climbers properly fixed to their supports. Tedious as these directions may seem, their fulfilment will be io THE BOOK OF CLIMBING PLANTS found to repay the planter in the greater rapidity with which the plants will become established and the quick manner in which they will cover their allotted space, compared with those planted with insufficient preparation.

Sometimes it is necessary to plant climbers in positions where the soil is already so permeated with the roots of trees or shrubs that a newly-established plant has little chance of obtaining the nourishment it requires. It is, in such cases, advantageous to sink a bottomless cask in the soil and fill it with a suitable compost so as to give the climber time to establish itself and strength to compete with the other roots.

While the proper preparation of the site for a climber is of the highest importance, it is also needful to give it regular supplies of nourishment when it begins to exhaust the provision made at planting. Too often this is forgotten, and the once free and vigorous plant shows signs of failure and decrepitude. Mulching with decayed manure and top-dressing with fresh soil and artificial fertilisers are beneficial, and, where it can be applied without being offensive, liquid manure will often work wonders in restoring health and vigour. In many positions, such as under the eaves of a dwelling-house or against warm walls, climbers frequently suffer much from drought, and they ought to be well watered in dry weather, giving plentiful soakings and not mere superficial waterings on the surface. Where this is necessary, the need for a stimulant in the way of liquid manure or a top-dressing of a good artificial manure is all the greater, as the frequent waterings tend to exhaust the soil by washing the manures into the sub-soil.

While, as a rule, those who plant climbers desire an immediate effect and should therefore attach them to their supports at once, it has been found that a few climbing plants, such as the Wistaria, grow eventually with more rapidity if they have been laid along the ground for the first season. This point is worthy of more consideration than it has received. Another recent discovery is that a certain number of climbing plants, of which the Clematis may be cited as an example, require to have the lower part of the stems shaded from the direct effects of the sun, especially when newly planted and when the flow of sap is consequently less plentiful. This shading can be easily afforded by planting some low shrub or herbaceous plant in front.

In some positions, such as rambling over a tree or among other things in the wild garden, climbing plants are best left unpruned and with but little interference. Yet it is seldom that this can be done without lowering the beauty of the effect they produce, and pruning or training of some kind is usually required and is almost always needful if the plant is to be seen at its best. Even the freest rambling Rose clambering up some tree is improved by cutting out some of its weak wood and removing all that is decayed. It is no addition to its charms to see a great dead branch projecting from the cloud of flowers, and thus a little timely attention will add greatly to the attractions of the plant. So, too, while Clematis Jackmanni and some others of free habit look very beautiful when rambling of their sweet will up a trellis or over an arch, a little timely training will make them more pleasing still ; while a careful study of the needs of the plants in the way of pruning will give results which will surprise those who have not fully considered the benefits derived from this necessary operation.

Formality of training is especially to be avoided with climbing plants, but, in general, there is less of this than of neglect in restraining them so as to induce them to put forth their best features. One may instance the difference caused by regular clipping of Ivy on walls when compared with the results of the common practice i2 THE BOOK OF CLIMBING PLANTS of leaving it to grow rampantly until it requires a drastic treatment which will spoil its beauty for a long time.

It is impossible to detail the respective methods of training and pruning all these plants. Some flower on the older wood, and, in these cases, the strong growths should be left and the weak ones cut out with all decayed wood. Others, again, bloom on the young shoots of the current year. In this case, the old ones ought to be cut out and the fresh, young shoots encouraged. Some flower on spurs produced from the old wood, and are best treated by cutting out a number of the weakly shoots and shortening those left. In all cases a study of the particular species is necessary, as all the species in one genus do not always give the best results under the same treatment in the way of pruning. In the following pages some guidance is generally given where it is thought necessary, but it may be remarked that many amateurs do not prune early enough, and often leave until autumn or spring what should be done as soon as flowering is over.

Supports for outside climbers deserve a few remarks. All walls are not of equal value as affording a suitable medium for the support of such as attach themselves to them. The least satisfactory is one whose surface is covered with cement, and it is with great difficulty that plants with aerial roots can attach themselves to this. Unpainted stone or brick makes the best walls, the latter being the warmer. It is often necessary to fasten the plants to the walls at the outset, and this may be done by means of shreds or, preferably, with some of the patent wall nails, which have soft metal tops, for bending round the stem of the plant.

Trellises are favourite supports for wall plants and afford an ornamental support for climbers which require tying or which can attach themselves to them by means of their tendrils. Wire trellises are favourites with

CLEMATIS, FAIRY QUEEN {Photo by E. J Walhs)

f many, and certainly possess the important merit of permanence and of requiring little expense to maintain them. The writer greatly prefers the appearance of those made of timber, which, also, seem to be more acceptable to the plants themselves. Wire trellis ought always to be painted so as to keep the frost from having the effect on the plants it would have were they left exposed.

Wooden trellis is very inexpensive, and its duration will be all the greater if it receives one or two coats of paint before being nailed together. A common thickness is a quarter-inch, but a little more is advisable. Three coats of paint are necessary at first, and one of raw linseed oil before painting will repay the outlay. Ready-made trellis is largely used, and is generally of good quality, while it is considerably cheaper than if made to order by an ordinary carpenter. Where it has to be affixed to posts sunk in the ground, the latter should be creosoted, tarred, or charred at the base and, if possible, fixed in concrete.

One of the best methods of training climbers to walls is by means of galvanised wires attached to spikes with eyes and tightened with a raidisseur at one end. There are several suitable kinds of spikes and raidisseurs. These wires are also suitable for climbers grown under glass.

For such climbers as Clematis flammula a good support is supplied by fixing lengths of wide-meshed wire netting to the wall, an inch or two from it, each length being fastened to the next by tying wire.

For archways and arbours either wire or wood may be used, and the wire arches sold in such quantity do very well, though buyers sometimes make the mistake of purchasing an arch which is too low in the centre, with the result that the climbers are in the way of those passing beneath. Seven or eight feet will be more suitable than six. Rustic arches are expensive, and need not be of an elaborate character where they are to be entirely covered by the plants. A simple arch of four upright poles with cross ones will do perfectly well for many things.

The pergola is rapidly becoming a favourite erection in gardens and owes its chief interest and beauty to the climbers which are trained to its pillars and shade its pathway. The pergola might be introduced into more gardens with advantage, but it ought always to be in such a situation that it forms either the entrance to a part of the garden or a pleasant feature of some path which leads to a definite object, instead of being, a? some are, without an apparent raison d'etre beyond that of affording a purely scenic effect. The structure of the pergola will depend upon the means of the owner, and may be an elaborate stone or brick erection, on which are laid cross beams of wood or trunks of trees to which the climbers are attached. Or it may be a simple erection of larch or other poles with others laid lengthways and crossed by similar poles. Light iron pillars bearing timbers can also be used, but the wooden pergola is generally the prettiest and the most welcome to the climbing plants. The uprights may be bedded in concrete in the soil or have their ends tarred or charred to preserve them.

For a pillar, nothing looks so well as an unbarked tree of moderate thickness, but iron ones, either plain or formed of lattice work, are sometimes used. Other more or less elaborate contrivances, such as a stout central pole with chains radiating from it, are also formed.

Climbing plants are subject to the attacks of various pests, both in the open and under glass. In the open these enemies are usually worse on a wall than elsewhere, and the less it is covered with foliage the greater the difficulty in keeping the plants free from them.

Aphides are the causes of much annoyance and loss, but may be destroyed by one of the many prepared insecticides now in the market, which are usually in a convenient form for use, and are efficacious if applied according to the maker's directions. A good preparation is made from one pound of soft soap and one pound of Quassia chips boiled in three gallons of water for about three or four hours, strained, mixed with other three gallons of water, and applied warm.

Under glass, fumigation, is usually the most suitable way of dealing with Aphides, and the old remedy of tobacco-paper is becoming superseded by XL ALL or other insecticides, which are more safely and conveniently applied.

Red spider is often troublesome, especially under glass, and may be dealt with by Gishurst Compound or one of the numerous preparations for the purpose, as well as by dusting flowers of sulphur on the leaves, or using such a solution as one pound of flowers of sulphur to two pounds of quicklime, boiled in four gallons of water.

Fumigation with some insecticide is also efficacious under glass ; while walls on which pests have gained a hold may be cleansed by mixing one pound of flowers of sulphur and two ounces of soft soap with clay and soot mixed with water to the consistency of paint.

Mildew is also very troublesome, and Bordeaux Mixture is one of the best remedies for plants outside. It is poisonous, and a wise precaution is to refrain from applying it to fruits within some weeks of their being gathered. A good recipe for its preparation is I lb. quicklime, dissolved in cold water, with I lb. sulphate of copper, dissolved in a little hot water, added together when cool to 10 gallons of water, and applied with a spray, stirring thoroughly. Some add I lb. of treacle to the lime, as it slacks, to enable it to adhere more firmly.

Scale and mealy bug are bad pests under glass, and may be destroyed by such things as Kerosene Emulsion,

B

Fir-tree Oil, or Gishurst Compound, applied precisely as directed on the packages. This is essential, as many plants are injured by not adhering to these directions.

In most cases it is much better to purchase some of these proprietary preparations than to make one which might be improperly compounded or made from material not fresh and thus ineffective.

Under Glass

Where the structures are so arranged that the climbers can be planted in a specially prepared bed, they are generally more satisfactory and more healthy than in pots. The bed should be thoroughly prepared, properly drained and filled with a compost of good, mellow loam, leaf soil and decayed manure, with some bone meal. In this bed the climbers ought to be carefully planted in a firm manner.

It is not always possible to plant climbers out under glass, and they may therefore be grown in large pots or tubs, filled with such a compost as above described. Since the soil will soon become exhausted from becoming filled with roots, as much of the old soil as possible should be removed without taking out the plant, and replaced by fresh earth. Occasional waterings with liquid manure or water in which an artificial fertiliser has been dissolved, are necessary to maintain the plants in health when the pots become filled with roots.

The necessity of repotting may be retarded by fitting a zinc ring on the top of the pot or tub, and filling this up with fresh earth. This will delay what is frequently a troublesome task when the climbers are trained to the walls or roof.

Wire trellises, or wires strained along the walls, roof or rafters, are the best method of training climbers under glass. The wires should be a few inches from the glass for roof climbers, and a little off the wall for those trained against a trellis. Many plants of climbing habit are frequently trained to balloon-shaped wire frames. Several other designs for such trellises are also employed for the purpose of training such plants where not wanted to grow to a considerable height, and often for exhibitive purposes.

Plants of a twining habit should have cords or wires to twist round unless trained to branches.

If careful training is desirable for outdoor climbers it is even more necessary with those under glass, and care must also be taken that their growth is not too thick for the plants beneath those on the rafters.

Ventilation also requires some consideration, and as a planted-out climber cannot be removed to another part of the house, climbing plants ought to be in such a position that they will not be subjected to draughts of cold wind when the ventilators are open.