Hedge is an important adjunct to every garden. It is necessary to demarcate the garden from public road and from adjacent gardens particularly in flat gardens. Besides its utility as screens, hedge is necessary between flower and vegetable garden, to provide a background for annuals if shrubbery does not exist and also to enclose a rose garden or a childrens corner in a park or public garden. A windscreen is also wanted when strong breezes, hot or cold blow from one direction during certain seasons of the year and frosts. It is useful to screen the manure pit, potting area, servants quarters and other unsightly views.
Growing the hedges:
The majority of hedges are propagated by cuttings but where seed can be obtained the cost of raising a large number of plants in their delicate stage is difficult. If this cannot be carried out sow at the following rates per 100 metres; Duranta 1 kg, Inga dulcis 1kg, Jaint (Sesbania) 150 gms, Mendi (Lawsonia) 250 gms, Dodonea (Sanatta) 250 gms. Hard seed such as that of Acacia modesta should be soaked in warm water for 24 hours.
Selection of plants
A hedge of Breynia rhamnioides is often seen in gardens and is very ornamental when in berry. Bauhinia acuminata in spite of its large leaves makes an effective display of white flowers even when brought to a shape. Caesalpinia pulcherrima ages fast when severely pruned but if trimmed slightly it provides tall hedge. Clerodendron inerme forms neat hedge or edge of varying height for m20 cm to 2 metres. It forms a compact hedge between 20-120 cm. C.inerme is not touched by cattle and white ants leave it alone.
Duranta in its many varieties holds first place in Bengal, D.variegata being very ornamental. Next comes Lawsonia (Mendhi) which is better in dry localities than in lower Bengal. Dodonea viscosa (Sanatta) is also an up country hedge but this latter should not be cut back as it is liable to die off in three or four years. Nerium and Tecoma are two others that might be used. Dracaena fragrans and D.sticta are good hedges for a shady spot. Hibiscus of several kinds form excellent hedges but H.liliflorus and H.schizopetalus are chiefly used.
Ehretia buxifolia as well as Serissa foetida and Malpighia coccigera are small leaved evergreens for shady situations. Polyscias (Aralia) of many kinds. Codiaeum (Croton) Eranthemum and Graptophyllum are ornamental shade loving hedge plants. Crotons of the narrow leaved and small foliage varieties are better hedges than those with large foliage. Plumbago capensis and P.zeylancia, Meyenia (Thumbergia) erecta and M.affinis are dwarf types of flowering shrubs that can be used for a hedge. In Bangalore we have seen Plumbago capensis cut down to 15 cm and in bloom. Other shrubs that can be used for hedges are Caryopteris, Mussaenda, Rhapiolepis and Rondeletia.
Euphorbia pulcherrima, if backed or having a supporting hedge in front can provide a fine mass of colour in the cold months. The last pruning should be done in August September. Jacquinia ruscifolia is an evergreen hedge with orange red flowers and needledtipped leaves and ideal hedge but difficult to propagate. Justicia gendarussa can be clipped to15 cm and allowed to grow upto a metre. Lagerstroemia indica in many colour variations, though bare in the cold weather, is a fine flowering hedge in April-June and if two colours are planted alternately provides a pretty effect when in bloom.
Ligustrum neilgherriensis, one of the privets, is not to be despised and the Lantana, though so frightful a weed, can be retained as a dwarf plant with frequent clipping though the non-seeding types are recommended. Malyaviscus can be cut back to form a 1 metre hedge or allowed to grow 2-3 metres high. When in bloom it is very effective.
Murraya (Kamini) and Tropis aspera (Sheora) are slow growing but clip well. Jasminum pubescens, Coffea bengalensis, Barleria (Jhati), Ixora especially I.ragoosula,I.coccinea and I.strica. Daedalacanthus and Strobilanthes are flowering hedges that are well known and easily grown. Roses form excellent hedges and many of the cacti such as Cereus, Opuntia as well as Euphorbia antiquorum, E.trigona and E.tirucalli are used in exposed positions for hedge work. Pedilanthus tithymaloides will be found as hedges surrounding village huts. Being poisonous to cattle it is left severely alone.
Sesbania aegyptiaca (Jaint) is a fast-growing hedge reaching a height of 2 metres in a couple of months; it must be grown from seed and is a great favourite in the drier parts of India for a tall temporary boundary hedge. After two years it commences to become rugged and should be replaced. Another quick hedge is Cajanus indicus (Arhar) but this grows too rapidly in Bengal.
Thuja orientalis is an excellent evergreen hedge, 2-3 metres in height. At an elevation of over 1000 metres a different type of plant is cultivated for hedges. Here are some varieties: Spirea, Kerria japonica, Berberis (Barberry), Habrothamnus elegans, Fuchsia, Heliotrope, Euonymus, Ligustrum (Privet), Buxus (Box) Hydrangea, Philadelphus, Hibiscus syriacus, Cupressus and Ancuba.
For very tall hedge several trees lend themselves to pruning: Polyalthia longifolia is one of the best, Putranjiva roxburghii, P.acuminata, Anogeissus, Diospyros embryopteris Grevillea robusta and Pithecolobium are others that can be recommended Pongamia glabra and Inga dullics are also used. Thevetia nerifolia, Erythrina of many kinds, Haematoxylon campechianum, Schinus terebinthifolius, Cryptomeria, Cupressus and other conifers are considered good when cut back to a height of 3-4 metres.
Casuarina equistifola if pruned before large trunk forms, makes a very neat hedge. Acacia farnesiana and Parkinsonia aculeata are both useful but do better in dry situations. Pisonia alba (tree lettuce) which forms hedges of pale coloured foliage, is grown in South India and Ceylon but not elsewhere to any extent. Commence cutting back when the seedlings are 20 cm high and repeat when the shoots are 40 cm a quick thick hedge from the very beginning is then ensured. Thevetia nerifolia is poisonous to cattle and goats and make a neat-clipped hedge 3-4 metres high.
On a wire fencing Jacquemontia violacea is ideal, Ipomea palmata (Railway Creeper) and I.sincrata and Antigonon (Sandwich Island Creeper), Clerodendron splendens, Ficus repens, Passiflora pruinosa. Tristellatia austrulis, Thunbergia fragrans and T. alata and Vallaris hynei are good for screening. For a very shady situation Rhycospermum jasminoides, Asparagus plumosus and Lygodium scandens are suggested.
Ptychosperma mcArthuri will grow 4-6 metres and not spread more than 1.5 to 2.0 m in width. Rhapis flabelliformis, on the other hand, while growing form 2-3 m in height, sends out runners, which must be constantly removed. Areca lutescens grows as tall as the Kentia but bushes out more.
This depends on the size of the plant. Trees should be planted 2-3 m apart, shrubs 15-50 cm apart and Alternanthera, etc., (edging) 2 cm apart if planted in a single row but when staggered double the distances. Duranta, Lawsonia etc. can be thickened when the hedge has grown up, by having the pruned cuttings, planted in between or on either side of the growing bushes. For hedge planting calculate 9 plants per mete row of planted singly 10 cm apart and 12 in a double row if planted 15 cm apart staggered.
Care of hedges
The first requirement for a hedge is impenetrability and the next neatness. Any prickly plant, such as Inga dulcis or the thorny type of Duranta, will not ensure an absolute cattle or thief proof hedge in its earlier stages, so run a barbed wire through the bushes form the ground or plant a row of pineapple, Agave, prickly cactus or thorny Euphorbia at the base and the case is altered. Always keep jungle away from the roots of a hedge. In the dry season fork up the soil and flood when Mendhi (Lawsonia) or Duranta are pruned, during the wet weather, plant the cuttings so as to fill gaps.
Usually hedges receive little attention till they become thin. The plants are pruned heavily in the rains, add manure at the close of the Monsoon. Feed hedges, especially those that are clipped regularly by giving superphosphate of lime and bone meal 50 gms each, 12 gms sulphate of potash and 50 gms sulphate of ammonia per two metres row, every six months. Once a year dig in cow manure as the rains break. This might seem superfluous but the results will amply repay the attention given
Pruning of hedges
Some varieties have to be left to grow as in nature, i.e. Pandanus, Euphorbia, etc but kept within bounds by the removal of side growth or the central head. In Euphorbia and Opuntia, the taller portions broken off can be replanted in the gaps to thicken the hedge. For low hedges, 50 cm to 1.0 metre high, clip frequently during the rains but once a year cut back the old wood below the maximum height to restart a new top do this in May or June.
Use a sharp pair of pruning shears for small twigs but a secateur will be necessary for larger stems. It is best to stick to a simple shape instead of attempting battlements, turrets, balls, columns, etc. arches can be grown on an iron rod bent to shape, the shrub kept in position by being loosely tied with strong wire to the rod.
Shapes of hedges
A hedge is apt to become wedge-shaped the top widening out, if not carefully clipped square. A rounded top is difficult to keep unless the type of hedge is slow, compact growing and small leaved. Hedges are also cut on a slope but here too the Mali often makes a mess of the shape. It is best to have wooden or iron stakes painted green, sunk in the hedge at intervals on which string can be tied and used as a guide. Stick to a square cut hedge.
Topiary is practised only in few traditional gardens. The plants that have small foliage and are of slow growth are good for using in topiary. The results required takes years to attain and one careless clipping will spoil the entire design. Stating with a ready-grown plant, stems are bent and held in position with wire if they do not naturally grow at the required angle. A rough clipping to get the general outline follows and as new shoots develop these are either trained to fit in with the design or removed. Simple shapes, a ball, spiral, table, cube etc., are not so difficult to obtain, it is when birds or beasts or even man is to be moulded that the topiarist tackles a tough proposition. Topiary work gives an old world appearance to a garden but these clipped bushes should not be scattered aimlessly all over the garden. A formal garden is best suited to topiary work. For simple shapes the following can be used Hibiscus, Thuja and Cupressus, Putranjiva and Polyalthia but for the more intricate Murraya exotica, Duranta repens, Ehretia buxifolia and Tropis aspera are used.
When using wire to model the bus hor tree to the rough outline care should be taken that this does not cut too deeply into the bark. Stoppage of sap will mean poor growth or death of a stem.