Rocks Gardens TREATING FOWLS FOR LICE

New Zealand Journal of Agriculture, Volume 82, Issue 3, 15 March 1951, Page 257

Rocks Gardens

TREATING FOWLS FOR LICE

By <

C. K. ELLIS,

Horticulturist, Department of

Agriculture, Dunedin.

FEW features in a garden can provide such a variety of interest in so little space as a wellplanned and carefully planted rock garden. The smallest of sections may contain a rock garden housing a charming and representative collection of alpine plants, but few features of the garden are so neglected and so ill understood. Rock gardening has increased in popularity markedly during the past few years, mainly because of the adaptability of these gardens to the requirements of space and because more money is available for gardening as a hobby.

THE chief function of a rock garden is to provide the plants grown in it with conditions approximating those of their natural habitat. Alpines are the most typical of all rock plants and are mainly natives of high crags in the mountainous parts of the world. Therefore, the aim in a rock garden should be to provide as far as is possible the soil and atmospheric conditions of those regions. Selection of Site During the brief alpine summers the sun is fierce and baking, and many alpine plants have downy leaves to protect them from the withering rays. Ample moisture is provided for roots at this time of the year by melting snow, the water draining sharply through the open, gritty soil. Downy foliage is likely to rot quickly in winter should excessive moisture be present over the crowns of the plants, but a blanket of snow prevents this until summer returns. For these reasons, drainage must be ample on the site selected, and where winters are damp provision must be made for covering downy-leaved species with panes of glass or other types of hand-lights, which is not necessary with -leaved species. Soils having a high content of sand

in fact, all naturally light soilsrarely need any special attention to drainage, but in heavier soils, such as clays, a layer of rubble about Ift. down is necessary, with a sprinkling of coarse grit over the top of the soil to ensure rapid removal of surface moisture. Most alpines have long running roots to enable them to draw moisture and nourishment from crevices deep down among the rocks, for surface soil in mountainous districts is often scanty. The second major consideration, therefore, is to ensure that an adequate depth of soil can be obtained before the rocks are placed in position. It is desirable that the situation having these qualities should be in as open and sunny a position as possible, reasonably removed from walls and large trees, which restrict the free circulation of fresh air essential to the welfare of alpine plants. The slope of the site also is important in that it directly affects the types of plant which may be cultivated. A south slope should be used for plants easily scorched by the sun, and a north slope for those requiring maximum warmth. Some sites, such as those on an east slope, may receive full sun in the mornings, with the rays falling less directly during the afternoons; the reverse is the case on a west slope. For example, plants disliking a sudden thaw under the direct rays of the sun on a clear winter morning should be planted on a west slope. The prevailing wind and the direction from which most of the rain comes are other factors to be considered. For instance, in a district where most showers come from a westerly quarter, a west slope receives more direct rain than does an east one, and this factor influences the suitability of a species for a position; that is, whether a plant should be grown in a wettish place at the bottom of such a west slope or in a dryish place near the top of an east slope. Soil Conditions The great majority of rock plants, especially the alpines, prefer a rich soil, light and porous in winter but cool and moist in summer. An excellent soil is a coarse, gritty one, rich in decayed vegetable matter, but as a whole alpines are . not particular about soil and most of them thrive in a

Heading photograph by Jack Welsh and Sons.

medium which approaches that described. However, some require special soil conditions, but an area between rocks can readily be scooped out and the required compost substituted.

In their natural environment rock plants have the soil about their roots completely covered by stalks and leaves, and each plant touches its neighbour or the surrounding rocks, thus preventing exposure of the surface to sun and wind and retaining moisture. Until the plants in a rock garden have grown large enough, it is advisable to cover the soil about the roots with coarse sand or grit in sufficient quantity to prevent the soil from drying out.

A neutral soil condition should be the aim, for this, with slight additions, can be varied to alkalinity or to acidity. Types of Rocks Wherever possible the natural rock of the district should be used. Limestones, mudstones, and sandstones present a rugged, weather-worn appearance and their cracks . and crevices provide a cool root-run for the plants. Porous stones are excellent, for they absorb and retain moisture, but in many areas of New Zealand hard volcanic rocks predominate and porous stones are not always available. However, most of New Zealand’s rocks will suffice, and only the hardest, most impermeable ones, such as the granites, should be avoided.

The basaltic rocks found on many of New Zealand’s hills are ideal, for they have an outer crust of weathered material into which some of . the flat, creeping plants will root and they are often encrusted with mosses and

lichens, which lend a pleasing natural appearance in the garden.

Any natural formation should be retained as a basis and the rest of the construction work done around and among it. Big rocks are essential here and there, and the whole surface should be set fairly thickly with rocks of varying sizes, and preferably of the same geological type. To obtain the most pleasing effect, the rocks should, within reason, be as large as the facilities for moving them and the size of the garden will allow. Construction Work Where sedimentary rocks (limestones and sandstones) are available, problems of construction are small, because the flat or rectangular slabs make it comparatively simple to build what appear to be natural outcrops. This type of rock should first be built into layers of varying thicknesses, individual rocks of each layer being of approximately the same length and breadth. For the most natural effect, all the layers should be tilted back at the same angle and the “grain” of the rocks should be parallel throughout. In general, it is better to use a limited number of bold features than a large number of small ones. If the area being built on is small, single rocks of varying sizes may be substituted for layers, but the same simple rules must be adhered to. Perhaps the simplest way of building is to decide on the position of a large, clearly defined outcrop, use it as a foundation, and build round it.

If rounded volcanic rocks are the only ones available, the gardener’s difficulties are somewhat magnified and he is obliged to be guided more by his own artistic nature than by set rules. However, the careful selection and placing of a few large rocks with prominent faces of the greatest possible height does much to simplify the problem. The placing of the smaller rocks is a matter of taste.

The pocket system of placing rocks is not the most desirable except on steep slopes where it is necessary that rocks be close enough together to prevent the soil being washed down. Where the slope will allow, it is better to leave spaces between the rocks in which small covering plants may be grown, thus decreasing the number of shelters for pests and adding to the natural effect.

In all cases and whatever the type of rocks . used, it is essential that each one be firmly set, that all the crevices be tightly packed with good soil, and that none of the rocks closely overhangs the soil surface to form harbours for slugs and snails. Choice of Plants Though the final selection of plants may well be left to the owner to make according to his likes and dislikes, a few points should be borne in mind. To have bloom for the longest possible period of the year is the primary aim, and for this small-growing bulbs which flower in late winter and early spring are invaluable. After this the true alpines will furnish colour through summer and autumn. Dwarf shrubs or perhaps a herbaceous perennial may be included, but size is the limiting factor and such plants usually are suitable only for the larger rock gardens. Stronger growers tend to overrun the garden and smother less luxuriant and perhaps , more beautiful species, ; so they must be limited in number and, when established, be cut back regularly and kept in check. As wide a variety of species as possible should be selected, but overcrowding must be avoided. Planting Methods In small gardens planting only single specimens of a species or variety is probably

Erica photograph on opposite page by Jack Welsh and Sons; all others by Douglas Elliott.

Much confusion has been caused in the past by the use of popular names, which vary from place to place, so in the following lists only botanical names are given.

wise, but in larger gardens it is advisable to plant three or more in a group to provide a broad mass of colour rather than a tiny patch. Planting should be done in spring or in autumn, the latter being the better, but not later than early April, for the roots make little growth after then. If plants are to be set out in late summer or autumn, the work should be delayed until after they have bloomed, for then new growth is made. The roots of alpines should be spread out carefully so that they are not cramped and the soil rammed down firmly about them. Thorough watering must always follow planting.

Plants from pots may be planted at any time if the soil is neither too wet nor too dry. The crocks should oe removed from the bottom of the ball of soil and, if necessary, the roots spread gently to relieve congestion. A crevice in which plants are to grow. should be well filled with good gritty soil, rammed firm, and the plants set in a small hole scooped from the surface. If necessary, a specimen may be held .in place with a small stone until it becomes established. General Maintenance Weeding, removal of dead flower heads, and watering during dry spells are minor tasks which must ■be performed if the rock garden is to be successful. A topdressing of a thin layer of light loam and leaf mould during spring is beneficial. As soon as the larger, more vigorous subjects have finished blooming, they should be trimmed back and all older parts of the plants as well as dead stems and foliage should be removed, but the greatest possible surface coverage must be retained. During late summer . and autumn specimens may be increased by division, and plants that have not progressed in one spot may be lifted and

given another chance elsewhere, perhaps in a different soil. Occasionally, because of loss of vigour by starvation, it may be necessary to lift a plant, remove the exhausted soil, replace it with fresh soil of a suitable composition, 1 and replant the specimen.

Soaking the soil thoroughly once a week is better than frequent light waterings, which wet only the upper layers of soil and tend to draw the roots up into tins region. If this occurs, the plants suffer greatly with the next onset of dry weather. Pests and Diseases Ants, though they do not destroy foliage, tend to injure the root systems by the building of their nests. The method of control recommended is to dissolve lib. of sugar in 1 pint of hot water, and add loz. of sodium arsenate; soak a piece of cottonwool in ■ this poisonous mixture, drop it into a tin with a perforated lid, and place it near the nest. Ant poisons should be handled with care, and containers should be labelled carefully and placed beyond the reach of children. After using all such poisonous materials the hands must be scrupulously washed. Aphides may be eliminated readily by the use of a mild nicotine insecticide. It should be sprayed gently over the plants at 10-day intervals until all traces of the pest have gone.

Earwigs, cutworms, and woodlice: The following preparation is recommended: Sprinkle loz. of paiis green over 21b. of dry coarse bran; in this

state the mixture may be stored. When it is required for use, mix the bran with warm water to which a little treacle has been added until it is damp but sufficiently crumbly to spread over the soil. This mix will cover about 400 sq. yds. v Red spider can be controlled by spraying with lime sulphur. ' Slugs and snails are the worst pests affecting subjects in the rock garden, but the following method of control is usually effective: Mix 2 handfuls of coarse bran or oatmeal with a crushed half tablet of metaldehyde and place it in small heaps about the garden, kept dry by pieces of grass lying over the top of them. These baits attract and paralyse the slugs. The bodies should be removed each day and new traps set. Several proprietary compounds for the control of such pests are available. Fungous diseases: Bordeaux mixture or one of the proprietary colloidal sulphur sprays is satisfactory for controlling rusts and other fungous diseases.

Propagation of Plants

Rock plants may be increased by seed (sown as soon as possible after after it has ripened), by cuttings, or by division of the roots in spring or autumn. As a rule, the home gardener is better advised to raise his plants from cuttings or by division of roots than from seed, which is a long and sometimes difficult process.

Cuttings should be taken from sturdy shoots which have ripened or are beginning to ripen, as callus and root formation occur more readily with this type of wood. Such cuttings should be taken while sap movement is steady, and most of the lower leaves should be removed, or at least reduced, to minimise water loss by transpira- , tion. The base of a cutting should be. a clean, straight cut made with a very sharp knife, immediately below a joint, or node, from which the leaves spring. The length of this cutting is decided by the distance between the nodes; for instance, if the nodes are lin. apart, the cuttings should be 3 to 4in. long, Half this length should be buried in the soil. Cuttings of soft-wooded plants require a little protection. Some type of glass covering should be provided to preserve humidity and some sort of shade to give protection from direct sunlight. Shrub cuttings may be taken in autumn when the wood is quite mature, in late midsummer when the

wood is half matured, or in early summer when the shoots are “soft” or only beginning to ripen. Cuttings of most of the hardier shrubs taken in autumn may be struck in sandy soil in the open, but half-matured and soft cuttings should be given the protection of glass, as should cuttings of the hardy evergreen conifers. Anv convenient well-drained recepcle such as a pot or a pan, or even a box, may be used to house the cut tings. They should not be set too deeply- two-thirds of the length of a hard-wood cutting should be inserted in the compost and about half the length of a soft one. The base of the cutting should always sit firmly on the so il a t the bottom of the hole made for it, or a pocket of air will be left which will merely deprive the cutting of valuable moisture. The compost should be pressed down firmly around the cuttings and no leaves should be allowed to touch the surface; if they do > they will rot . . x Roots of spring-flowering plants are best divided in late summer or

autumn; spring is the best time for those that flower in late summer or autumn. The clump should be lifted with as much root as possible and the crowns divided with a sharp knife, which will do the minimum of injury to the roots. The older crowns should be discarded, the stronger new ones being retained and replanted as soon time permits. Composts A r , .. .... ... „ A good compost for striking cuttings consists of 1 part by bulk of leaf mould or peat, 1 part of loam, and 3 parts of sharp river sand. All constituents should be sieved through a 1/5 or jin. mesh. a standard compost for rock garden work may be mixed in the proportions o f g parts by bulk of loam, 3 parts o f pea t or i ea m ould, and 5 parts of coarse sand. For alkaline-soil plants this compost may be altered by the addition of lime and for acid lovers by the addition of aluminium sulphate or acid organic material.

Put ,1 or 4 drops on the abdomen (above), but •avoid letting any fall on the vent opening. _ Place a drop on the underside of each wing (right), then & drop on each side of the breast (lower left), and finally a drop between the neck feathers below the head (lower right). This treatment does not kill lice eggs, so they must be allowed to hatch out and the treatment repeated twice at 10-day intervals.

The most effective way of combating body, wing, and head lice on (owls is to treat the birds individually, placing pure nicotine sulphate of 40 per cent, strength directly on the skin so that the feathers retard the evaporation of the chemical.

* Bulbous plant or one with a ground-level or underground perennating organ. , ; t Dwarf tree or shrub

Plants for Sunny Places Cotyledon species Antirrhinum glutinosum Achillea species ■••Crocus species ‘"•‘Cyclamen neapolitanum Arabis ■ albida and other species . Aubrietia deltoidea varieties Aethionema species " t Cypripedium species Borago laxifiora * Allium species Daphne blagayana ; Calandrinia umbellata Androsace species Daphne cneorum Campanula species Antennaria dioica fDeutzia gracilis Cotoneaster adpressa . ■ Arabis albida Epimedium alpinum Cotoneaster congesta Arenaria speciesArmeria maritime Erica species Cotoneaster horizontalis *Eranthis.. hyemalis Cotoneaster horizontalis Cytisus kewensis ■■•Fritillaria species . Gaultheria nummularioides Armeria alpina ffGaultheria hispida .Gaultheria prociimbens Aster species and varieties ff Hemerocallis species Linaria cymbalaria.. Azibrietia deltoidea and varieties ’"Leucojum autumnale ■ Lithospermum pro stratum [Berberis darwini nana *Meconopsis baileyi (betoniciMimulus radicans vernum folia) .. .. Nertera species Campanula species Celmisia species fCeratostigma plumb aginoides [Ceratostigma willmottianum Cistus species *Colchicum species fCorokia cotoneaster ■■‘Crocus species Cytisus procumbens . [Cytisus purpureus ■ . Dianthus species and varieties Dicentra . species . *Galanthus byzantinus . Mimulus species fMitraria coccinea Polygonum affine Rosa alpina Nertera depressa * Omit hog alum umbellatum Rosa pyrenaica Sedum species Ourisia species . *Oxalis lobata Primula littoniana and other species Ranunculus species - Thalictrum alpinum' Trillium grandiflorum Viola, species Rosa pyrenaica Sedum species Thymus species Dwarf Trees and Shrubs Abelia chinensis Abies pectinata nana Andromeda species . Azalea species and varieties *Galanthus elzvesi Acid-Intolerant Species Betula alpestris nana Genista species Acid-Intolerant Species Betula alpestris nana Cassinia fulvida Gentian a acaulis Achillea species . Cupressus fletcheri Gentiana corymbifera Aethionema species Cupressus lawsoniana minima ■ Gentiana pneumonanthe , Alyssum montanum glauca Gentiana saxosa Alyssum saxatile Cupressus obtusa nana Gentiana sino-ornata and other species Gewn species, , Gypsophila species Hebe species ‘"•‘Anemone alpina Anemone Pulsatilla Aqulegia . species Cistus species ... ‘"Cyclamen species Corokia cotoneaster Daboecia species ■ Daphne alpina ... -. ■. .... Erica species . ■ - • Helianthemum vulgare varieties Hclichrysum species Gentiana species Juniperus communis alpina, Gypsophila species Juniperus communis . alpina, compressa, and nana Hyacinthus azureus Kalmia latifolia Hyacinthus azureus ■ Lithospermum gastoni Kalmia latifolia Hypericum, species Iris in o min at a Lithospermum gastoni Papaver alpinum Magnolia stellata . Papaver nudicaule . Picea glauca conic a *Iris reticulata Phlox subulata . . '. Pice a orient alis nana Iris unguicularis (stylosa') Primula (most alpine species) ■ Pernettya mucronata and other species - Sedum species Rhododendron species and 'Lithospermum species Sempervivum species varieties Mazus radicans Sedum species . . Sempervivum species Sternbergia lutea Spiraea bullata [Magnolia stellata ■ *Tulipa species . Rhododendron species and varieties Spiraea bullata stellata Thuya occidentalis ericoides Mesembryanthemum species ‘""Tulipa species ’ Wahlenbergia. saxicola Thuya occidentalis ericoides Thuya orientalis compact a Morisia monanthos (hypogaea) Muscari azureum ■ Zenobia pulverulenta Narcissus species Nepeta species Nierembergia species Papaver alpinum Phyteuma species t Rhododendrons. of the R. calostratum series Lime-intolerant Species f Andromeda species * Anemone sulphurea * Anemone nemerosa Azalea species and varieties Daboecia cantabrica Bulbs and Other Species with Underground or Ground-level Perennating Organs • Allium species Anemone species Rosa dwarf species . .. Rosmarinus officinalis Saponaria species Saxifraga. species and varieties Daphne alpina Daphne cneorum *Erica species (except E. Bulbocodium species Chionodoxa luciliae and other species Colchicum autumnale Scilla sibirica Daphne alpina Daphne cneorum * Eric a species (except E. ■ came a") Bulbocodium species Chionodoxa luciliae and other species Colchicum autumnale Crocus species Cyclamen coum Sedum species [Gaultheria hispida Sempervivum arachnoideum and fKalmia latifolia Cyclamen europaeum other species Lithospermum prostratum Cyclamen neapolitanum . 5 ilene species Statice species *Meconopsis baileyi (betonicifolia") Fritillaria species Galanthus species Sternbergia lutea Teucrium species Thymus species Tulipa species. *Meconopsis baileyi (betonicifolia) \Pernettya mucronata Pieris species Primula (some species) Fritillaria species Galanthus species Hyacinthus azureus Iris species Leucojum vernum ■ Muscari azureus Veronica species Rhododendron (most species and Narcissus bulbocodium Wahlenbergia saxicola varieties) Narcissus cyclamineus Zauschneria microphylla Narcissus minimus Narcissus triandrus Plants for Shady Places Creeping or Trailing Species Scilla praecox Scilla sibirica — x Achillea species Achillea species Scilla verna — ' Scilla verna ‘"•‘Anemone species Alyssum montanum Tulipa clusiana Aquilegia species Alyssum saxatile Tulipa fosteriana Auricula species. Androsace species ■ Tulipa montana *Chionodoxa luciliae , Antennaria dioica Tulipa sylvestris Cotula species Antirrhinum asarina and other species