Amenity Horticulture: Challenges, Applications, and Solutions
L. Atuah (Ph.D)
Amenity horticulture- what it is and its
relevance
Challenges in amenity horticulture and the
way forward
Plants in the landscape
Plant use – functional and aesthetic
Maintaining amenity plants
Some plant disorders and their treatments
It can be referred to as landscape horticulture
or environmental horticulture.
The term landscape commonly refers to the
appearance of the land, including its shapes,
texture and colours. It also reflects the way in
which their various components combine to
create specific patterns and pictures that are
distinctive to particular localities.
The landscape or the natural environment has
gone through various modifications which are
man made.
Amenity horticulture therefore refers to the use
of plants in the landscape to effect aesthetic
patterns, enhancing comfort and pleasantness.
The plants may also serve other functional
purposes like checking erosion, screening etc.
Amenity horticulture is therefore applied in
such a way that it reflects the set of priorities of
the users of a particular environ.
Multi-professional collaboration is required to
produce the cohesion needed in our
landscapes/environs.
Name professionals that will be needed for
such collaboration and briefly explain why?
General challenges: Vandalism, litter,
poisonous plants, hideouts for ‘bad people’,
timeliness in keeping maintenance schedule.
Challenges peculiar to Ghana – name as many
as you can think of.
Education
Legislation
More research on ornamental plants and the
environment (implying provision of funds)
Re-organising the department of Parks and
Gardens
Innovative ideas like an award for Ghana’s
most beautiful suburb etc.
The plants in the landscape can be categorised.
They may be either of the following;
Trees
Shrubs
Herbaceous perennials
Grasses and creeping plants/ground covers
Climbers
Bromeliads
Ferns
Cacti and succulents
Water plants
Plantings in the landscape may either be formal
or informal.
Trees: The four main groupings of trees are
namely, foliage trees, flowering trees, conifers and
palms.
Some examples are enlisted in later slides.
A shrub may be distinguished from a tree
by the fact that it is bushy and mostly multi-
stemmed (i.e. woody, a plant smaller than a
tree and with several woody stems). Shrubs
are usually divided into two groups -
flowering and foliage. They are grown in
the landscape individually as specimen
plants or in groups for shelter belt, hedges,
bedding plants or in shrubberies.
Flowering shrub:
These are perennial herbaceous plants which
are either grown for their flowers or foliage.
They include bulbous, tuberous and
rhizomatous plants.
Climbing plants consist of both perennial
woody, herbaceous plants and annuals.
These plants have various devices for climbing
which include tendrils, twining stem, root-like
holdfasts and drooping or rumbling over a
support.
Since most climbing plants grow vigorously
and consequently carry a lot of vegetation,
stakes or supports used must be sufficiently
strong.
Turf grasses perform the function of ground
cover plants. They are grown mainly in lawns,
playing fields etc.
Ground cover plants are very useful on slopes,
irregular surfaces and in rocky areas where
mowing of grass is not possible.
Ferns belong to a group of plants which
produce pores instead of flowers and seeds.
The spores are found on the fronds, usually
beneath.
Suitable conditions for growth and
development; damp semi-shaded conditions
with protection from wind.
These plants can withstand a considerable amount of
neglect. This is possible because of their resistance to
drought, dry, hot and difficult conditions.
Cacti has adaptive features to cut down on loss of
water through transpiration. These are thickened
stems and spines which are modified leaves.
The fleshy nature of succulents allow for maximum
retention of moisture. Transpiration is further
reduced by a thin wax coating or woolly hairs plant
parts.
Three general groups of water plants;
Those which grow entirely beneath water, those
which have their roots and stem beneath water
surface, those with their roots growing in water
and stems and leave above water surface.
Avenue plants – Trees with clear trunks (allowing
for people to walk under) is ideal. The trees must
have aggressive root systems, should not have brittle
branches and not be messy (by way of leaf and seed
drop). The roots must have deep root system to
afford good anchorage.
Specimen plants – Plants with unique characteristics.
They should be sufficiently attractive to stand alone.
Hedge – Plants (especially shrubs) grown with close
spacing and trained in such a way to make a barrier
or mark a boundary.
House plants – they are plants which can be
expected to live permanently under room
conditions.
Trees
Avenue plantings
Provision of shade
Specimen
Noise control
Pollution control
Wind breaks
Shrubs:
Hedge
Median planting to reduce headlamp glares
Potted plant
Bedding plant
Border plant
Beds
Borders
Establishing an avenue:
In avenue planting there should be a layout and
design and the following should be considered:
Length
If an avenue leads from one definite point to
another, its length is automatically defined.
In other cases, the length should be decided in the
light of certain guiding factors including the following:
If too long, an avenue tends to become monotonous.
If very long, care must be taken to ensure that it is
not too narrow, in which case it will tend to shrink to
vanishing point before the end of it is seen.
If a very long avenue is made too wide, in order to
avoid the last pitfall (shrinkage), the trees of which it
is composed will appear to be dwarfed.
Avenues should not normally be more than one-half
to three-quarters of a mile in length if the above
points are to be avoided.
It is difficult to lay down the exact width of an
avenue. The habit of the species planted: large crown
trees need more space than those with narrow crown.
The table below can be used as a guide
The length of the avenue: long avenues should be
rather wider than those of shorter length.
The number of rows of trees of which the avenue is
composed: an avenue of two single rows should be
rather narrower than one with two double rows.
City conditions are often unfavourable for tree
growth and species must be selected which can
tolerate air pollution, dry conditions, glare from
pavements etc.
Suitable trees should be planted far enough from the
kerb to allow them to spread without too much
pruning. They should be kept clear of overhead
wires and underground services.
Discuss how a tree can be planted (Steps involved)
Trees in car parks
The task of accommodating trees within a car park is not
always straightforward as it may seem. The challenge on
site a car park; are usually hard surface, dry conditions,
lack of air and the intensity of the light which is thrown
up from the ground to the tree.
This can result in leaf scorch and abnormal transpiration
rate.
Vehicles may damage trees by reversing into them and
tree roots can be poisoned if fuel run-off gets into the
water supply.
To avoid the afore mentioned hazards it is
usually suggested trees in car parks be planted
between raised kerbs or in elevated boxes.
Hazard fencing at bumper height can go some
way to meeting practicalities but the careful
siting of trees in relation to the overall car park
design gives the best solution.
In tree selection, the tree should be able to
withstand pollution.
Essentials required are a shovel, rope/string, tape
measure, stakes/pegs, compost, spray paint
(optional).
If a really dense and bushy hedge from ground
upwards, it is advisable to plant young small plants.
The result of using large plants can often be that the
hedge is rather gappy at the base.
Soil preparation:
Prepare the ground by digging over a strip 60-90cm
wide and one spade blade deep.
Remove all weeds if a weedkiller has not been used
before hand.
Add organic matter such as garden compost, spread
it over the soil and mix in top 25 cm of soil with a
fork.
You may also mix in a general purpose fertilizer.
Planting
Planting distances vary from 30-60 cm, depending on
the plants’ final size, the size of hedge required and
plant vigour. For hedges thicker than 90 plant a
staggered double row 45 cm apart with plants 90 cm
apart.
Trim back damaged roots to healthy growth with a
sharp knife.
Spread out the roots, ensuring the planting depth is
correct (note that the previous soil mark on the stem
indicates how deeply the plants were grown in the
nursery).
Work soil between the roots, firm plants in so that
soil is in close contact with the roots. Then water.
Mulch to a depth of 7.5cm after planting to prevent
weeds.
Why will one plant a hedge?
What kind of plants are recommended for median
planting?
These are plants which are grown in beds and borders to
give color to a landscape environment. They include
annuals, biennials, herbaceous perennials, ferns, fern-like
plants, orchids, cacti and succulents and shrubs.
Beds stand as an island of selected flowering plants.
They could take any shape especially geometric shapes;
square, oval etc. If the bed is sited in a lawn you will have
to be careful your chosen shape will not hamper mowing
of the grass.
If you plan a large bed you will have to make provision
for access in order to facilitate maintenance.
Beds should be viewable from different angles.
Borders- They are planted against a wall or hedge.
The plants in a border will therefore be affected by
shadow from the wall, possible reduced impact of
rain.
Take into consideration the backdrop when planning
the colour scheme of the border.
Be aware also of the fact that maintenance works on
the wall or hedge can affect the plantings in the
border.
How can you establish a bed; square and circular shape?
Lawn: A smooth layer of land covered with turf.
Turf: A ground cover of grass which is kept mown
and which will stand a reasonable amount of traffic.
Verge: A narrow strip of turf between beds, paths,
walls etc.
Preparations involved:
Soil preparation is essential to ensure there is quick
establishment of uniform turf. The goal is to create a
fertile homogeneous root zone with acceptable
infiltration, aeration and drainage.
Depending upon the scope of the project advance
planning may be of relatively little or of very great
importance.
In general turf can be established from seeds or
vegetatively. This could be by sodding, plugging,
stolonizing and sprigging.
Sodding:
The process of installing mature turf in
large or small sheets, as opposed to spreading seed
or sprigs over a prepared area of bare soil.
Sod is established turf that is harvested with roots
and soil attached and transplanted from its place of
origin and installed like carpeting to grow in another
place.
Sodding is the most expensive method of turf
establishment but produces an established turf
within hours rather than weeks or months.
The only maintenance required during the early
weeks of establishment is daily watering when there
are no rains.
Sod is bought from a farm in the form of rectangular
pieces or as long rolled strips.
Stolonizing
: Every bud on a stolon can potentially
become a new plant.
Many tropical turf-grass do not produce viable seeds.
Stolonizing is therefore one of the methods for
establishment of turf.
Sprigging:
The process of vegetatively establishing
turf grass by spreading rhizomes or stolon over a
prepared seed bed and pressing them into the soil.
It is a modification of stolonizing. It involves placing
stolons in narrows spaced 15 to 20cm apart and
manually covered. 15 to 20% of the stolon should
extend above the surface.
The advantage over stolonizing is less risk of
desiccation.
The disadvantage is high labour cost.
Plugging: Small (5 to 10 cm) diameter pieces of sod
are transplanted into a prepared area 15 to 35 cm
apart.
Site preparation
•
This is the same irrespective of the method adapted
for establishment.
Steps: Debris removal
Elimination of existing vegetation and preventive
weed control. An ideal herbicide/weedicide
translocates through and kills the entire plant
without leaving a harmful residue in the soil.
•
Glyphosate known commonly as Kleenup or
Roundup will kill both annual and perennial
weeds.
•
Weeds also can be removed by digging.
•
Levelling – This involves changing the slope of
the area into an even gradient. This can be
adequately worked on from the subsoil before
spreading the top soil.
•
Soil amending – Depending on the soil
condition of the topsoil soil amending may be
needed to improve drainage, fertility or pH.
•
Surface preparation – The surface on which
the seed is to be sown should be free of clods
and form a tilth. A light raking will remove
remaining clods and provide the final surface.
•
Information on seed germination rate and
purity must be noted.
•
Seed rate – Generally package directions are
the best source of information on seeding
rate.
For heavy seeding may be done but it have
some disadvantages. There will be quick
results but it will be under over crowded
conditions and weaker seedlings will be
weeded out by stronger ones which will
eventually form a stand of plants equal to that
which would have been formed naturally at a
lower rate.
Seeding Techniques: For large areas
Mechanical methods should be adopted.
Trees
Shrubs
Grasses
This may involve the following:
Pruning
Watering
Mulching
Shading
Removal of Competition/Weed Control.
Staking
Fertilization
The general principles for pruning trees and shrubs will
be considered.
Pruning is the removal of plant parts on purpose to
enhance growth and maintain the usefulness of the plant.
Pruning tools:
Examples of hand pruners – Pruning saw, hedge
shears, hand pruners, lopping shears.
Purpose for pruning:
Size control
Health improvement
Appearance improvement
Pruning young trees:
This implies pruning at transplanting and within the
first few years after transplanting.
(why may pruning be a requirement at transplanting)
During the first few years of transplanting the plant
develops the main branches which will form the
support structure for the foliage.
Pruning directs the growth of those branches in
order to create a strong tree.
What is a strong tree?
Look out at the early stages of plant development for
double leaders and remove them.
Most trees have a ‘central leader’ but a occasionally
two leaders develop causing a fork.
If the weaker of the two lead branches is not
removed, it poses a potential cause for damaging of
the tree trunk with time.
As each leader increases in diameter, it exerts
pressure against the other at the base and this can
cause eventual splitting.
Selection of scaffold branching.
The lateral branches along the main stem is referred to
as scaffold branches.
It is best to control the extent of branches in the
initial stages of development of a tree. It is best if
they are widely spaced and evenly along the trunk.
Pruning mature trees:
A tree that was properly pruned when young should
need little pruning when mature.
Three-cut pruning method is adopted fpr removing
large branches/limb
Mature branches are usually heavy and easily
break and rip off tree back if being sawed off
by one cut.
The three-cut pruning:
1
st
cut is made under the branch about 30 cm
away from the trunk and goes halfway through
the branch.
The 2
nd
cut is made about 8 cm away from the
1
st
cut from the top of the branch. This is cut
through.
The 3
rd
cut removes the stub.
Some trees may naturally not have a central leader
and it will be a mistake to prune to have one.
Pruning of such trees may involve only
desuckering and removal of crossing and inward-
growing branches.
Pruning shrubs:- This involves;
Thinning
Heading back
Renewal Pruning
Shrubs are multi-stemmed coming out from the
basal portions of the plant. With time as they grow
by increasing in height and number of stems there
will be the need to thin.
This is because as the older stems age and
lengthen, they have the tendency to shade out the
bottom foliage.
This results in the shrub becoming bare at the base.
Thinning consists of removing the oldest stems at
ground level. This shortens the shrub and
encourages new shoots to grow from the roots and
refoliate the bottom.
Heading back:-
This consist of cutting twigs or small branches
to just before/above an outward pointing bud.
It encourages new growth to develop outward
and eliminate crossing branches.
Used to rejuvenate and shorten over grown
shrubs.
Where branches are cut back they are reduced to
stubs 5 - 8 cm long.
Renewal pruning involves thinning techniques as
well as cutting back.
It a drastic measure which will make the plant
unsightly in the first two years.
What is a hedge?
(Recall)
Hedges can be classified as formal and natural
(informal).
Pruning of a natural hedge/shelter belt is same
as pruning a shrub i.e. thinning and heading
back.
Formal hedges require frequent pruning to
maintain a neat appearance.
What is important is the selection of the correct
hedge shape.
Sound mowing is perhaps the single most important
factor contributing to the attractiveness and
longevity of any turf-grass area.
The height of cut is important. The height to which a
given grass can be mowed is directly related to its
ability to produce enough leaves and to keep up with
production of carbohydrates.
Some creeping grasses with fine leaves, such as
cynodon and zoysia, when properly fertilised and
watered, are able to produce adequate leaf surface at
very low mowing heights.
It has been determined that removal of more
than one-third of total leaf area results in
severe physiological shock.
With this in mind, only the growth rate will
determine the mowing frequency.
Mowing equipment:
There are a number of mower types. The most
accurate are the reel mowers (cylinder mowers),
rotary mowers are intermediate and sickle-bar
mowers are the least.
The proper choice of mowing equipment
depends on the type of grass and the
conditions of usage and maintenance.
For high-quality sport or recreational areas,
reel mowers are recommended for cutting.
They provide a clean even cut and leave the
turf looking the most attractive.
Rotary mower should be used where perfect
appearance is not necessary. And where ease of
operation, maintenance and price are of
significant concern.
Sickle bar mowers are the simplest and roughest.
They are used mainly across road side and other
areas where turf appearance is of secondary concern.
Reel mowers:
A reel mower consists of a horizontal rotating
cylinder, the reel, with attached blade and stationary
bed knife, which is parallel to the ground.
The reel usually bears between 3 and 7 blades, and
the width of the mower usually ranges from 50 to 80
cm depending on the model.
Rotary mowers:
The blade of a rotary mower is usually a single
sharpened metal bar suspended parallel to the
ground at its centre point.
It spins in a horizontal plane, striking and
severing vertically growing leaf blades.
They do not provide an even cut and they
cause certain amount of mutilation at the point
of impact.
Mowing should be done only when the grass is dry.
This is because the mower is less likely to clog with
soggy clippings.
Secondly grass blades are more susceptible to
disease invasion through the cut surface when wet.
It is important to sharpen mower blades often. A
clean cut minimises the damaged area and reduces
tip browning of the blades.
It also decreases moisture loss and eliminates
bruised blades which are a site for disease entry.
A key to determining the kind of disorder is to know
the cause of it.
The cause may be attributed to either a parasitic
organism or an environmental condition.
Examples of parasites:
Rodents, insects and microorganisms such as
bacteria and fungi.
Examples of environmental conditions:
Heat, drought, pollution etc.
There are some disorders that may be as a result of deficiencies
or toxicities. This may result in manifest the manifestation of
certain symptoms depending on the nutrient element that is
lacking or in toxic levels.
Note that symptoms are first seen in the oldest leaves when the
nutrient element can be easily moved about the plant.
In deficiency, the small supply is shunted to areas of growth in
an attempt by the plant to complete the life cycle.
Symptoms are first seen in the youngest leaves when the
element in poor supply is held firmly where it was first used.
Deficiencies may often result in stunted growth
and off-colour leaves.
Other causes of stunted growth may be;
Waterlogging, salinity, drought, disease eg root
rot, insects, viruses.
Too much or too little light
Wrong day-length
Toxins in medium
Problem
Symptoms
Pests
Symptoms
Caterpillars
Parts of leaves eaten away.
Borers
Borrow into stems, underneath
part of leaf eaten away whiles top
remains untouched.
Leaf miners
Scribble-like patterns on leaves.
Grasshoppers Large portions of leaves eaten.
Aphids
Disfigurement of leaves and buds.
Mealy bugs
Raised spots or dots on leaves, leaves drop.
Nematodes
Yellowing, general lack of vigour, roots
knotted. Death of irregular sections of
leaves and spotting.
a. Fungi caused:
Wilt
Entire or a section of plant wilts and
cannot recover even after watering.
Leaf spot Spots (concentric rings with dark centre)
appear on foliage and sometimes on
stems and flowers spreading to cover all
other parts. Spots reduce photosynthetic
area of
leaves and plant may dies.
Blight Quick wilting and death of young and
growing tissues such as flowers and twig.
Rust
Reddish-brown spots on foliage and
stems.
Virus caused:
Curly top
Twisting, distorted
foliage.
Mosaic
Mottled light and dark
areas on foliage.
If the plant is diseased, the control may be both
cultural and chemical and understanding of both is
essential to restoring and maintaining plant health.
Cultural control:
Watering
Sanitation
Pruning
Roguing
Crop Rotation
Resistant Varieties and species
Explore the world of amenity horticulture, its significance in landscape design, challenges faced, and innovative solutions. Learn about the diversity of plants used for functional and aesthetic purposes in creating attractive environments. Discover the need for multi-professional collaboration, general challenges like vandalism and timeliness, and specific issues in Ghana. Explore potential improvements through education, legislation, research, and creative initiatives. Categorize plants commonly found in landscapes to enhance your understanding of this field.
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Presentation Transcript
Amenity horticulture- what it is and its relevance Challenges in amenity horticulture and the way forward Plants in the landscape Plant use functional and aesthetic Maintaining amenity plants Some plant disorders and their treatments
It can be referred to as landscape horticulture or environmental horticulture. The term landscape commonly refers to the appearance of the land, including its shapes, texture and colours. It also reflects the way in which their various components combine to create specific patterns and pictures that are distinctive to particular localities.
The landscape or the natural environment has gone through various modifications which are man made. Amenity horticulture therefore refers to the use of plants in the landscape to effect aesthetic patterns, enhancing comfort and pleasantness. The plants may also serve other functional purposes like checking erosion, screening etc.
Amenity horticulture is therefore applied in such a way that it reflects the set of priorities of the users of a particular environ. Multi-professional collaboration is required to produce the cohesion needed in our landscapes/environs. Name professionals that will be needed for such collaboration and briefly explain why?
General challenges: Vandalism, litter, poisonous plants, hideouts for bad people , timeliness in keeping maintenance schedule. Challenges peculiar to Ghana name as many as you can think of.
Education Legislation More research on ornamental plants and the environment (implying provision of funds) Re-organising the department of Parks and Gardens Innovative ideas like an award for Ghana s most beautiful suburb etc.
The plants in the landscape can be categorised. They may be either of the following; Trees Shrubs Herbaceous perennials Grasses and creeping plants/ground covers Climbers Bromeliads Ferns Cacti and succulents Water plants
Plantings in the landscape may either be formal or informal. Trees: The four main groupings of trees are namely, foliage trees, flowering trees, conifers and palms. Some examples are enlisted in later slides.
Scientific name Common name Some characteristics Ficus benjamina Azadirachta indica Pithecellobium saman Michelia champaca Weeping fig Neem Rain Tree Champac Weeping spreading tree Upright spreading tree Spreading tree Medium size erect and Pyramidal tree Erect fan shaped plant Ravenala madagascariensis Traveller s Tree
Scientific name Common name Some characteristics Cassia fistula Cassia nodosa Lagerstroemia speciosa Poinciana regia Plumeria alba Golden shower Pink shower tree Queen flower Flamboyante Frangipani, Forget-me-not Pendulous yellow flowers Pink flowers Showy purple flowers Large scarlet flowers White flowers
Scientific name Common name Some characteristics Araucaria heterophylla Araucaria bidwilli Cupressus Sp Thuja orientalis Casuarina equisetifolia Norfolk Island Pine Bunyan bunyan Cupressus Thuja Whistling pine Pyramidal evergreen Spiny evergreen Bushy and dense Dense busy pyramidal tree Needle-like leaves
Scientific name Common name Some characteristics Roystonea regia Royal palm There are both tall and dwarf varieties Tall and dwarf varieties Erect tree with spiral leaves Cocos nucifera Caryota urens Coconut palm Toddy Palm Washingtonia filifera
A shrub may be distinguished from a tree by the fact that it is bushy and mostly multi- stemmed (i.e. woody, a plant smaller than a tree and with several woody stems). Shrubs are usually divided into two groups - flowering and foliage. They are grown in the landscape individually as specimen plants or in groups for shelter belt, hedges, bedding plants or in shrubberies.
Flowering shrub: Scientific name Common name Some characteristics Acalypha hispida Allamanda cathartica Monkey tail/red fingers Allamanda Slender long flowers Yellow trumpet shape flowers Has thorns and is a climber Different kinds exists; red, yellow, pink flowers Large heads of crimson flowers Bougainvillea glabra Purple bougainvillea Hibiscus rosa-sinensis Hibiscus/Rose of China Ixora duffi Double red ixora
Scientific name Common name Some characteristics Acalypha willinckii Acalypha wilkesiana Variegated acalypha Acalypha tricolor Has heart-shaped leaves Brown leaves blotched with red Terminal leaves are variegated white Has purple leaves Breynia nivosa Ice plant/snow plant Pseuderanthemum atropurpureum Polyscias spp. Purple eranthemum Panax Several kinds exist
These are perennial herbaceous plants which are either grown for their flowers or foliage. They include bulbous, tuberous and rhizomatous plants. Anthurium andreanum Anthurium lily Scientific name Common name Some characteristics Bears large waxy scarlet flower Numerous varieties with different colours When well irrigated it continue to flower throughout the year Bears yellow bracts Cannot withstand drought Canna spp Canna lily Gerbera jamesonii Barberton daisy Heliconia bihai Pentas parviflora Lobster claw Red Pentas/flaming Katie
Climbing plants consist of both perennial woody, herbaceous plants and annuals. These plants have various devices for climbing which include tendrils, twining stem, root-like holdfasts and drooping or rumbling over a support. Since most climbing plants grow vigorously and consequently carry a lot of vegetation, stakes or supports used must be sufficiently strong.
Scientific name Common name Some characteristics Monstera deliciosa Scindapsus aureus Thunbergia alata Ceriman Scindapsus Black-eyed Susan Has perforated leaves Quick growing Yellow funnel shaped flowers Very useful for covering bare walls Has brittle papery leaves Ficus pumila Creeping fig Petrea volubilis Purple wreath
Turf grasses perform the function of ground cover plants. They are grown mainly in lawns, playing fields etc. Ground cover plants are very useful on slopes, irregular surfaces and in rocky areas where mowing of grass is not possible. Chrysopogon aciculatus Love grass/Tafo grass Scientific name Common name Some characteristics Grows in full sun and semi- shade full sun and semi-shade Does not thrive under shade Violet flowers open in the morning closes by afternoon Very showy yellow flowers Axonopus compressus Cynodon dactylon Setcreasea purpurea Carpet grass Bermuda grass Purple heart Tribulus cistoides Tribulus
Ferns belong to a group of plants which produce pores instead of flowers and seeds. The spores are found on the fronds, usually beneath. Suitable conditions for growth and development; damp semi-shaded conditions with protection from wind. Asparagus plumosus Asparagus fern Scientific name Common name Some characteristics Adiantum capillus-veneris Nephrolepis exaltata Maidenhair fern Sword fern Cannot recover once wilted Fronds are erect and stiff Fern-like with need-like branchlets Can grow both in full sun and semi-shade Asparagus sprengeri Asparagus fern
These plants can withstand a considerable amount of neglect. This is possible because of their resistance to drought, dry, hot and difficult conditions. Cacti has adaptive features to cut down on loss of water through transpiration. These are thickened stems and spines which are modified leaves. The fleshy nature of succulents allow for maximum retention of moisture. Transpiration is further reduced by a thin wax coating or woolly hairs plant parts.
Scientific name Common name Some characteristics Agave americana Century plant Spreading plant with a large rosette of thick and stiff leaves. Sparsely foliaged with spiny stem. Erect house plant bears clusters of scarlet flowers. Euphorbia splendens Christ s Thorn Kalanchoe blossfeldiana Flaming Katy Succulent leaves which are glossy purple beneath and green above. Erect cylindrical pointed leaves. Rhoeo discolor Lady-in-boat/Moses in the cradle Sansevieria trifasciata laurentii Mother-in-law tongue
Three general groups of water plants; Those which grow entirely beneath water, those which have their roots and stem beneath water surface, those with their roots growing in water and stems and leave above water surface. Scientific name Common name Some characteristics Nymphaea spp Water lilies Waxy leaf surface with closely set minute hairs Floating plant preferring shallow waters Floating and bears small dull violet flowers Pistia stratiotes Water lettuce Thalia dealbata Water Canna
Avenue plants Trees with clear trunks (allowing for people to walk under) is ideal. The trees must have aggressive root systems, should not have brittle branches and not be messy (by way of leaf and seed drop). The roots must have deep root system to afford good anchorage. Specimen plants Plants with unique characteristics. They should be sufficiently attractive to stand alone. Hedge Plants (especially shrubs) grown with close spacing and trained in such a way to make a barrier or mark a boundary.
House plants they are plants which can be expected to live permanently under room conditions.
Trees Avenue plantings Provision of shade Specimen Noise control Pollution control Wind breaks
Shrubs: Hedge Median planting to reduce headlamp glares Potted plant Bedding plant Border plant
Beds Borders Establishing an avenue: In avenue planting there should be a layout and design and the following should be considered: Length If an avenue leads from one definite point to another, its length is automatically defined. In other cases, the length should be decided in the light of certain guiding factors including the following:
If too long, an avenue tends to become monotonous. If very long, care must be taken to ensure that it is not too narrow, in which case it will tend to shrink to vanishing point before the end of it is seen. If a very long avenue is made too wide, in order to avoid the last pitfall (shrinkage), the trees of which it is composed will appear to be dwarfed. Avenues should not normally be more than one-half to three-quarters of a mile in length if the above points are to be avoided.
It is difficult to lay down the exact width of an avenue. The habit of the species planted: large crown trees need more space than those with narrow crown. The table below can be used as a guide Length of avenue (m) Width of avenue (m) 91 91-182 182-365 365-548 548-640 640-751 24 9 12 15 18 21 The length of the avenue: long avenues should be rather wider than those of shorter length.
The number of rows of trees of which the avenue is composed: an avenue of two single rows should be rather narrower than one with two double rows. City conditions are often unfavourable for tree growth and species must be selected which can tolerate air pollution, dry conditions, glare from pavements etc. Suitable trees should be planted far enough from the kerb to allow them to spread without too much pruning. They should be kept clear of overhead wires and underground services.
Discuss how a tree can be planted (Steps involved) Trees in car parks The task of accommodating trees within a car park is not always straightforward as it may seem. The challenge on site a car park; are usually hard surface, dry conditions, lack of air and the intensity of the light which is thrown up from the ground to the tree. This can result in leaf scorch and abnormal transpiration rate. Vehicles may damage trees by reversing into them and tree roots can be poisoned if fuel run-off gets into the water supply.
To avoid the afore mentioned hazards it is usually suggested trees in car parks be planted between raised kerbs or in elevated boxes. Hazard fencing at bumper height can go some way to meeting practicalities but the careful siting of trees in relation to the overall car park design gives the best solution. In tree selection, the tree should be able to withstand pollution.
Essentials required are a shovel, rope/string, tape measure, stakes/pegs, compost, spray paint (optional). If a really dense and bushy hedge from ground upwards, it is advisable to plant young small plants. The result of using large plants can often be that the hedge is rather gappy at the base. Soil preparation: Prepare the ground by digging over a strip 60-90cm wide and one spade blade deep. Remove all weeds if a weedkiller has not been used before hand.
Add organic matter such as garden compost, spread it over the soil and mix in top 25 cm of soil with a fork. You may also mix in a general purpose fertilizer. Planting Planting distances vary from 30-60 cm, depending on the plants final size, the size of hedge required and plant vigour. For hedges thicker than 90 plant a staggered double row 45 cm apart with plants 90 cm apart. Trim back damaged roots to healthy growth with a sharp knife.
Spread out the roots, ensuring the planting depth is correct (note that the previous soil mark on the stem indicates how deeply the plants were grown in the nursery). Work soil between the roots, firm plants in so that soil is in close contact with the roots. Then water. Mulch to a depth of 7.5cm after planting to prevent weeds. Why will one plant a hedge? What kind of plants are recommended for median planting?
These are plants which are grown in beds and borders to give color to a landscape environment. They include annuals, biennials, herbaceous perennials, ferns, fern-like plants, orchids, cacti and succulents and shrubs. Beds stand as an island of selected flowering plants. They could take any shape especially geometric shapes; square, oval etc. If the bed is sited in a lawn you will have to be careful your chosen shape will not hamper mowing of the grass. If you plan a large bed you will have to make provision for access in order to facilitate maintenance.
Beds should be viewable from different angles. Borders- They are planted against a wall or hedge. The plants in a border will therefore be affected by shadow from the wall, possible reduced impact of rain. Take into consideration the backdrop when planning the colour scheme of the border. Be aware also of the fact that maintenance works on the wall or hedge can affect the plantings in the border. How can you establish a bed; square and circular shape?
Lawn: A smooth layer of land covered with turf. Turf: A ground cover of grass which is kept mown and which will stand a reasonable amount of traffic. Verge: A narrow strip of turf between beds, paths, walls etc. Preparations involved: Soil preparation is essential to ensure there is quick establishment of uniform turf. The goal is to create a fertile homogeneous root zone with acceptable infiltration, aeration and drainage.
Depending upon the scope of the project advance planning may be of relatively little or of very great importance. In general turf can be established from seeds or vegetatively. This could be by sodding, plugging, stolonizing and sprigging. Sodding: The process of installing mature turf in large or small sheets, as opposed to spreading seed or sprigs over a prepared area of bare soil. Sod is established turf that is harvested with roots and soil attached and transplanted from its place of origin and installed like carpeting to grow in another place.
Sodding is the most expensive method of turf establishment but produces an established turf within hours rather than weeks or months. The only maintenance required during the early weeks of establishment is daily watering when there are no rains. Sod is bought from a farm in the form of rectangular pieces or as long rolled strips. Stolonizing: Every bud on a stolon can potentially become a new plant. Many tropical turf-grass do not produce viable seeds. Stolonizing is therefore one of the methods for establishment of turf.
Sprigging: The process of vegetatively establishing turf grass by spreading rhizomes or stolon over a prepared seed bed and pressing them into the soil. It is a modification of stolonizing. It involves placing stolons in narrows spaced 15 to 20cm apart and manually covered. 15 to 20% of the stolon should extend above the surface. The advantage over stolonizing is less risk of desiccation. The disadvantage is high labour cost. Plugging: Small (5 to 10 cm) diameter pieces of sod are transplanted into a prepared area 15 to 35 cm apart.
Site preparation This is the same irrespective of the method adapted for establishment. Steps: Debris removal Elimination of existing vegetation and preventive weed control. An ideal herbicide/weedicide translocates through and kills the entire plant without leaving a harmful residue in the soil.
Glyphosate known commonly as Kleenup or Roundup will kill both annual and perennial weeds. Weeds also can be removed by digging. Levelling This involves changing the slope of the area into an even gradient. This can be adequately worked on from the subsoil before spreading the top soil.
Soil amending Depending on the soil condition of the topsoil soil amending may be needed to improve drainage, fertility or pH. Surface preparation The surface on which the seed is to be sown should be free of clods and form a tilth. A light raking will remove remaining clods and provide the final surface.
Information on seed germination rate and purity must be noted. Seed rate Generally package directions are the best source of information on seeding rate.
For heavy seeding may be done but it have some disadvantages. There will be quick results but it will be under over crowded conditions and weaker seedlings will be weeded out by stronger ones which will eventually form a stand of plants equal to that which would have been formed naturally at a lower rate. Seeding Techniques: For large areas Mechanical methods should be adopted.
Trees Shrubs Grasses This may involve the following: Pruning Watering Mulching Shading Removal of Competition/Weed Control. Staking Fertilization
The general principles for pruning trees and shrubs will be considered. Pruning is the removal of plant parts on purpose to enhance growth and maintain the usefulness of the plant. Pruning tools: Examples of hand pruners Pruning saw, hedge shears, hand pruners, lopping shears. Purpose for pruning: Size control Health improvement Appearance improvement
