Horticulture: Laying Out Plants for Display

Introduction

Planting a garden is not simply a matter of putting plants into empty spaces.

Good planting design considers: Colour; shape; texture; height; habit; season; repetition; contrast; scale; proportion; maintenance; soil; light; drainage; biodiversity; sustainability

Before plants are planted, they should be laid out on the ground. This allows the horticulturist to see the proposed arrangement and make changes before the plants are permanently placed.

A good gardener should be able to look at a group of plants and ask:

Will these plants work together now, and will they still work together in five years?

Why Lay Plants Out Before Planting?

Laying plants out before planting allows you to:

check spacing

check plant quantities

assess colour combinations

identify gaps

avoid overcrowding

create repetition

establish a good rhythm

check height relationships

adjust the composition

avoid unnecessary digging

reduce plant losses

It is much easier to move a plant in a pot than to dig up an established plant.

Start with the Site

Before laying plants out, consider:

Soil

sandy
clay
loam
acidic
alkaline
fertile
poor
wet
dry

Light

full sun
partial shade
shade

Moisture

dry
moist
waterlogged

Exposure

sheltered
windy
coastal
exposed

Existing vegetation

Consider:

trees
shrubs
hedges
established perennials
existing bulbs

The principle is:

Right plant, right place.

Plant Labels and Plans

Before starting, check the plant labels.

Record:

botanical name
common name
mature height
mature spread
preferred soil
preferred light
flowering period
growth habit

Do not rely entirely on how large the plant looks in its pot.

A small plant may eventually become very large.

Plant Size vs Mature Size

One of the most common mistakes in planting is spacing plants according to their current size.

For example: A shrub may currently be 30 cm wide but eventually grow to 2 metres wide.

Planting it 30 cm from its neighbour may look attractive initially. Five years later it could be overcrowded.

Good planting design considers future size, not just today’s appearance.

The Basic Layout

A useful method is to divide the planting area into:

Back

Taller plants

Middle

Medium-height plants

Front

Lower-growing plants

However, this is only a starting point. Good planting can deliberately break this rule by allowing taller plants to move into lower areas and creating a more natural composition.

Planting in Groups

Plants often look stronger when planted in groups.

For example: 3 + 5 + 8

rather than: 1 + 1 + 1 + 1 + 1

Odd-numbered groups can produce a more natural visual effect. However, this is a design guideline rather than a law. Large plants may need fewer specimens. Small plants may need larger groups.

Repetition

Repeating a plant can create:

rhythm
continuity
unity

For example: Lavender → grass → lavender → grass → lavender

The eye begins to recognise a pattern. Repetition can link different parts of a garden together.

Rhythm

Rhythm is created when visual elements are repeated or progress through a space.

It can be created through:

colour
height
form
texture
plant species

Too little repetition can make a border appear disjointed.

Too much repetition can become monotonous.

Contrast

Contrast can make a planting display more interesting.

Contrast can occur between:

tall and short
dark and light
fine and coarse foliage
upright and spreading forms
smooth and textured leaves
warm and cool colours

For example:

fine grasses + large bold leaves

can create strong visual contrast.

Colour

Colour is often the first thing people notice.

Consider:

Warm colours

red
orange
yellow

These can appear energetic and visually strong.

Cool colours

blue
violet
some pinks

These can appear calmer and may visually recede.

Green

Green provides the framework for most planting schemes.

Different greens can be as important as flower colour.

Texture

Texture refers to the visual and physical character of foliage.

Examples include:

fine
coarse
glossy
hairy
spiky
fern-like

Combining different textures can make a border more interesting even when flowers are absent.

This is particularly important in perennial and shrub borders.

Annual Displays

An annual display is generally designed to provide strong seasonal impact over a relatively short period.

Examples include:

summer bedding
formal bedding schemes
temporary displays
seasonal containers

Annual displays are often changed regularly.

The design therefore focuses heavily on:

immediate impact
colour
uniformity
flowering period
repetition
seasonal theme

Laying Out an Annual Display

For an annual display, plants can often be arranged relatively close together to create a strong visual effect quickly.

The aim may be:

maximum impact in one season.

Typical approaches include:

blocks of colour
stripes
geometric patterns
repeated groups
contrasting colours
formal designs

Plants are generally chosen to perform over the same relatively short period.

Advantages of Annual Displays

They can provide:

strong seasonal colour
rapid visual impact
flexibility
opportunity to change the design each year
opportunities for experimentation

They are useful where a garden needs:

seasonal decoration
event displays
formal bedding
temporary colour

Disadvantages of Annual Displays

Annual bedding can require:

large quantities of plants
frequent watering
regular feeding
deadheading
replacement
preparation each year
disposal of spent plants

Some schemes also require significant:

labour
energy
plastic pots
compost
transport

This raises sustainability questions.

Perennial and Shrub Borders

A perennial and shrub border is intended to provide a longer-term planting structure.

Unlike annual bedding, the plants are expected to remain in the garden for several years.

This changes the design process.

The gardener must consider:

What will this border look like next month?

but also; What will it look like in five years?

Laying Out a Perennial Border

When laying out a perennial and shrub border, consider:

mature plant size
spread
seasonal interest
flowering period
foliage
winter structure
evergreen plants
plant competition
maintenance
access

The border should not be designed only for its peak flowering period.

Four Seasons of Interest

A successful perennial and shrub border can provide interest throughout the year.

Spring	bulbsearly perennialsfresh foliageblossom
Summer	flowersgrassesstrong foliage
Autumn	seedheadsberriesautumn colour
Winter	barkstemsevergreen foliageseedheadsstructural forms

The best borders are not necessarily the ones with the most flowers.

They are the ones that remain interesting.

Annual vs Perennial and Shrub Border

Annual display	Perennial/shrub border
Usually seasonal	Long-term
Designed for immediate impact	Designed for development
Often high colour intensity	Colour, form and structure
Plants may be replaced annually	Plants remain for several years
Close planting may be appropriate	Mature spacing is essential
Often highly formal	Can be formal or naturalistic
More frequent replacement	Lower replacement frequency
High seasonal maintenance	Ongoing maintenance
Future growth less important	Future growth essential

Spacing Annuals

Annual plants are often planted relatively closely.

This can create:

rapid coverage
fewer visible gaps
strong colour blocks

However, planting too closely can encourage:

poor air circulation
disease
competition
excessive watering requirements

Always follow the recommended spacing for the plant.

Spacing Perennials

Perennials should be spaced according to:

mature spread

rather than the size of the pot.

Allowing plants to grow into one another can produce a natural effect.

However, excessive overcrowding can lead to:

competition
reduced airflow
disease
weak growth
difficult maintenance

Spacing Shrubs

Shrubs require particular care when calculating spacing.

Consider:

mature height
mature width
growth rate
pruning requirements
root competition

A shrub border should not be planted as though every shrub will remain the size it is when purchased.

Planting in Drifts

A drift is a group or sweep of plants arranged to create a strong visual mass.

Drifts are particularly useful in:

naturalistic planting
prairie-style planting
large borders
public landscapes

Instead of scattering individual plants:

plant in groups and sweeps.

Planting in Blocks

Blocks create a more formal effect.

For example:

AAAAA

BBBBB

AAAAA

This can be effective for:

bedding
formal gardens
geometric designs

It can also become visually repetitive if overused.

Naturalistic Planting

Naturalistic planting often uses repetition; drifts; grasses; seedheads; seasonal succession.

The arrangement may look informal but is often carefully designed. Naturalistic does not mean random.

The Importance of Focal Plants

A focal plant attracts attention.

It might be:

a specimen tree
a large shrub
a strongly coloured plant
an unusual architectural plant

Focal plants should be used carefully. If everything demands attention then nothing becomes the focal point.

Negative Space

Not every area needs to be filled with plants.

Space between plants can:

emphasise individual specimens
improve visual clarity
provide access
allow plants to develop
make maintenance easier

The temptation to fill every gap can result in overcrowding.

Access and Maintenance

Before planting, ask:

Can I reach this plant later?

Can you:

weed?
prune?
divide?
deadhead?
mulch?
inspect for pests?
repair irrigation?

A beautiful border that cannot be maintained is poorly designed.

Planting for the Future

A perennial border changes over time.

Year 1

Plants may appear:

small
widely spaced
sparse

Year 2–3

Plants begin to fill the border.

Year 4–5+

Plants may reach mature dimensions.

This is why patience is important.

A border should not be designed solely to look perfect immediately after planting.

Sustainability in Planting Design

Sustainable planting aims to reduce unnecessary:

resource use
waste
water use
chemical inputs
energy
replacement planting

Possible approaches include:

selecting plants suited to the site
reducing irrigation
reducing annual replacement
using durable materials
retaining healthy soil
increasing biodiversity
choosing long-lived plants

But sustainability involves trade-offs.

The Downsides of Sustainability

Sustainability should not be presented as a simple list of benefits.

Every approach can have disadvantages.

1. More expensive initially

High-quality:

peat-free compost
locally sourced plants
durable materials
water-saving systems

may cost more initially.

2. Slower establishment

Some sustainable approaches favour slower-growing, long-lived planting.

A client wanting immediate impact may prefer faster-growing plants.

3. More management knowledge required

Reducing chemical use means the gardener needs better skills in:

observation
identification
prevention
biological control
physical control

4. Peat-free compost can behave differently

Peat-free growing media can have different:

water-holding properties
nutrient levels
structure

They may require changes in watering and feeding.

5. Local is not automatically more sustainable

A locally produced plant grown in an energy-intensive heated greenhouse may have a different environmental impact from a plant produced elsewhere under lower-energy conditions.

“Local” is not automatically synonymous with “sustainable”.

6. Native is not automatically better

Native plants can provide valuable habitat.

However, the best planting choice depends on:

site
climate
soil
habitat requirements
existing biodiversity

7. Biodiversity can conflict with design objectives

A formal historic garden may require:

clipped hedges
lawns
bedding
controlled planting

Removing all formal management in the name of biodiversity could destroy the garden’s historic character.

8. Sustainable materials still have impacts

Materials such as:

timber
stone
compost
ceramics
metal

all require:

extraction
manufacture
transport

Sustainability means reducing impacts, not achieving zero impact.

9. “Low maintenance” is not maintenance-free

A perennial border may require less replacement than annual bedding.

It still needs:

weeding
cutting back
division
pruning
mulching
monitoring

10. Some sustainable choices may reduce visual impact

A wildlife-friendly planting scheme may not provide the immediate, highly controlled appearance expected from traditional bedding.

The designer needs to understand the client’s priorities.

The Sustainability Question

Instead of asking:

“Is this sustainable?”

ask:

“More sustainable than what?”

This is a much better horticultural question. For example:

Replacing annual bedding with perennial planting may reduce:

annual plant production
transport
compost use
plastic pots
replanting

But it may increase:

initial establishment time
weeding requirements
plant division
management complexity

Sustainability is therefore about trade-offs and whole-system thinking.

Example: Annual Bedding vs Perennial Border

Imagine a formal entrance requiring strong summer colour.

Option A – Annual bedding

Advantages:

immediate impact
strong colour
predictable display
easy to redesign

Disadvantages:

annual replacement
high plant numbers
watering
feeding
waste
labour

Option B – Perennial planting

Advantages:

longer-lived
seasonal succession
potentially lower replacement
habitat value
structural interest

Disadvantages:

slower initial impact
more complex design
plants may spread unpredictably
seasonal gaps may occur
maintenance is still required

There is no universally correct answer. The correct answer depends on purpose + place + people + resources + time.

Practical Layout Exercise

Choose a border.

Step 1 – Mark the boundaries

Use:

string
canes
pegs
tape

Step 2 – Place the tallest plants

Position the major structural plants.

Step 3 – Place medium plants

Create groups and repetition.

Step 4 – Place lower plants

Fill the foreground.

Step 5 – Stand back

View the display from:

front
side
entrance
main viewpoint

Step 6 – Adjust

Move plants before planting.

Step 7 – Check spacing

Consider mature size.

Plant Layout Record

Site: ______________________________

Date: ______________________________

Planting type:

☐ Annual display

☐ Perennial border

☐ Shrub border

☐ Mixed border

Main colour

Secondary colour

Tallest plant

Lowest plant

Focal plant

Repeated plants

Main texture

Flowering season

Winter interest

Design Assessment

Stand back from your proposed planting.

Ask:

Does it have balance?

☐ Yes ☐ No

Is there repetition?

☐ Yes ☐ No

Is there contrast?

☐ Yes ☐ No

Are there focal points?

☐ Yes ☐ No

Is there seasonal interest?

☐ Yes ☐ No

Are plants spaced for mature size?

☐ Yes ☐ No

Can the border be maintained?

☐ Yes ☐ No

Does it suit the site?

☐ Yes ☐ No

Does it meet the client’s requirements?

☐ Yes ☐ No

Student Questions

1. Why should plants be laid out before planting?

2. Why should mature plant size be considered?

3. What is the difference between an annual display and a perennial border?

4. Why might annuals be planted relatively closely?

5. Why should shrubs not be planted according to the size of the plant in its pot?

6. What is a drift?

7. What is repetition in planting design?

8. Give three examples of contrast that can be used in planting.

9. Why is winter interest important in a perennial and shrub border?

10. Give three possible benefits of reducing annual bedding.

11. Give three possible disadvantages of a sustainable planting approach.

12. Why is “local” not automatically the same as “sustainable”?

The Professional Planting Test

Before planting, ask:

Does it suit the site?

↓

Does it suit the soil?

↓

Does it suit the light?

↓

Will it fit when mature?

↓

Does it provide seasonal interest?

↓

Does the arrangement have rhythm and repetition?

↓

Is there enough contrast?

↓

Can it be maintained?

↓

Does it meet the purpose of the garden?

↓

Is the environmental cost justified?

Remember

An annual display is usually designed for immediate seasonal impact.

A perennial and shrub border is designed for development over time.

Annual planting can provide spectacular colour but may require considerable:

water
labour
replacement
compost
transport
energy

Perennial planting can be longer-lived and potentially more resource-efficient, but it still requires careful design and maintenance.

Sustainable planting does not mean:

“Use as many environmental ideas as possible.”

It means considering the whole system.

A sustainable planting scheme should consider:

the plant

the soil

the water

the wildlife

the materials

the labour

the energy

the maintenance

the lifespan

and the purpose of the garden.

The best planting design is not necessarily the one with the most plants, the most flowers or the lowest environmental impact on paper.

It is the planting scheme that is:

appropriate, beautiful, functional, maintainable and considered over its whole life.

Key references

Royal Horticultural Society (RHS), guidance on planting design, plant selection, borders, seasonal displays and sustainable gardening.
Royal Horticultural Society (RHS), guidance on garden design, soil management and biodiversity.
Natural England, guidance on biodiversity and habitat creation.
Department for Environment, Food & Rural Affairs (Defra), environmental improvement and biodiversity guidance.
Dunnett, N. and Hitchmough, J., The Dynamic Landscape: Design, Ecology and Management of Naturalistic Urban Planting.
Robinson, N., The Planting Design Handbook.