Develop garden renovation and restoration skills, redevelop historic gardens with authenticity and integrity: a valuable commercially desirable skill for all landscape professionals.

Course Code: BHT243
Fee Code: S3
Duration (approx) Duration (approx) 100 hours
Qualification Statement of Attainment
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Understand How to Restore Gardens Authentically

Garden restoration involves trying to return a garden to a similar state to how it was originally conceived. For some gardens old records may be relatively easy to find. For instance, if the design was created by a designer of merit the materials may be archived in a private collection or library. If the company that created the garden is still in existence, records may be available through that company. Sometimes photographs can be found in private or public records. If people who used the property along time ago are still alive, they may remember details.

Learn the techniques behind successful garden restoration

Take this course to learn about how to restore old gardens to closely resemble the original. Find out how an understanding of garden history and styles can be significant and different ways to access records. Learn how to measure up a site, assess its current plants and hard landscape features, and decide what should be retained. Find out how to plan a restoration project and conduct risk assessments.

This course has been developed by professionals in both Australia and the UK, with the aim of being relevant throughout the world.

Lesson Structure

There are 8 lessons in this course:

  1. Landscape History and Design Styles
    • Ancient Middle Eastern Gardens
    • Chinese Garden History
    • UK Garden History
    • Important English Landscapers
    • European Gardens
    • Olmsted, Burle Marx, etc
    • The Worlds First Plant Collectors
  2. Surveying the Site
    • Survey Problems
    • What to Survey
    • Measuring Dimensions and Locations
    • Triangulation
    • Slope
    • Levelling Calculating Earthworks; volumes of irregular solids, using triangles, etc
  3. Assessment of Plantings and Features
    • Nature of Garden Restoration
    • Assessing Plantings
    • Considering Trees
    • Assessing Garden Features
    • Considering Degradation
    • Fasteners
    • Water Problems
  4. Selecting Components for Retention
    • What should be restored?
    • Renovating areas within a Garden
    • Pruning to Renovate
    • Windbreaks
  5. Work Programming and Risk Management
    • Where to start renovation
    • Be Prepared
    • What Order to Work in
    • Risks to the Project
    • Risks to the Workers
  6. Drainage
    • Water Logging on a Site
    • Poor Drainage Symptoms
    • Drainage Solutions
    • Reducing Erosion
    • Drainage Design
    • Understanding Gradients
    • Moving Existing Earth
    • Fixing Leaks
  7. Hard Landscape Feature Restoration
    • Paving and Paving Materials
    • Concrete
    • Gravel
    • Asphalt
    • Coloured Surfaces
    • Barriers and Walls
    • Maintaining Stone and Brick Walls
    • Outdoor Furniture
    • Protecting Outdoor Furniture
    • Painting Outdoor Furniture
    • Pond Management
  8. Planting Restoration and Maintenance
    • Improving Existing Plantings
    • Tree Surgery
    • Trees and Paving
    • Replacing Old and Overgrown Hedges
    • Rejuvenating an old Hedge
    • Rejuvenating Other Plants; controlling shape and size, pruning, etc
    • Rejuvenating Old Lawns
    • Perennials
    • Maintaining Herbaceous Borders
    • Controlling Weeds
    • Controlling Pests and Diseases
    • Conducting Tree Inspections
    • Chemical Safety


  • Outline the history of UK garden design and the influence of plant introductions.
  • Evaluate an established ornamental garden in order to determine any particular design style period, or plants of interest.
  • Describe basic methods for the survey and recording of the layout and content of an established garden, and explain the importance of detailed information including assessment of site factors.
  • Explain processes and the need for assessment and recording of the type, condition and future potential of a range of plantings and features in an ornamental garden.
  • Explain the main criteria used to select plantings and features for retention in a restored garden.
  • Explain the need and processes of analysis of collected information.
  • Prepare a summarised programme for organisation of garden restoration work
  • Assess risk and identify safe work practices
  • Recognise and explain the visible signs of the failure of old land drainage systems and describe remedial measures
  • Describe and explain the practical procedures necessary for the restoration of a range of hard landscape features.
  • Explain problems which may be encountered in the improvement of retained hedges, plantings and lawns.
  • Describe practical solutions for improving retained hedges, plantings and lawns
  • Evaluate the use of modern maintenance techniques in established gardens.

Restoration of Old Plantings

The restoration of plantings involves both:

  • Improving existing plants
  • Introducing new or replacement plants

Improving Existing Plantings
The scope of this type of work may include:

1. Attending to Environmental problems

  • Cutting back mature trees that are creating excessive shade, removing such trees and replanting with smaller shade creators
  • Correcting soil problems such as low fertility, depletion of organic matter, inappropriate pH
  • Providing temporary (and permanent protection) from weather extremes (eg. Wind breaks)

2. Removing Invasive Plants

3. Treating Plant Health Problems 

  • Fungal disease
  • Insect pests
  • Viral disease
  • Other pests (eg. rabbits, snails, mice, etc)

4. Pruning

Other Maintenance can also be important in how it affects the plants you are trying to rejuvinate, for example:
  • Install irrigation system, deep watering pipe
  • Laying mulch
  • Use of mechanised equipment

Replacing an Old Hedge
Sometimes the plants in a hedge are beyond restoration – the hedge may have been damaged by fire or disease. When restoring an old garden you may need to replace the existing hedge or put in a new hedge where an old one grew in the past.

Hedges and Neighbourhood Disputes
Hedges can cause disputes with neighbours. When re-planting a hedge:

  • Make sure that when fully grown (in width) it will be well within the garden and doesn’t encroach on neighbouring properties. Remember that any encroaching plant material including roots may be removed by the neighbours.
  • Choose plants that are easier to keep to a certain height so as to not over-shadow and exclude light to neighbouring properties or gardens in the future.
  • Make sure that a new hedge will not deprive neighbours of an important view.
  • Some hedges may need planning permission for removal.

Plant Choice
Some plants such as some conifers, will not tolerate constant cutting; and others simply do not develop dense, even growth. The best hedging plants usually have small leaves; though for larger hedges, larger leaved plants may be acceptable.
A large hedge will require a lot of plants - which is expensive; difficult-to-grow plants may be less desirable economically. However when replacing an old hedge in a garden restoration project it is best to choose the plants that were used originally, if at all possible or practical.

In choosing the plants, consider the following:

  • Is the hedge to be evergreen or deciduous? Deciduous and many evergreen hedging plants can be pruned more regularly and vigorously then some conifers which die back if you cut into old wood.
  • Informal or formal? Formal hedges need to be clipped frequently so choose a species that will tolerate frequent cutting. 
  • Height - consider the plant’s natural size at maturity – for a 1 m high hedge, don’t choose plants which naturally grow to 3 or 4 m.  
  • Density - a more open hedge will give better air circulation but less privacy.
  • What size plants are to be used? Advanced plants can be very expensive but will give an almost instant effect; smaller plants are cheaper and often give better results in the long run.
  • Quick effect - many fast-growing plants will rapidly develop into a dense hedge but will require frequent clipping to maintain a tidy shape. Some may also be short-lived.
  • For a uniform hedge - buy sturdy plants of around the same size. Branching is important so it’s best to select plants dense, bushy plants to get the hedge off to a good start.
  • Slow growing plants are often longer lived then fast growers. 
  • Pruning - hedges such as Taxus and Juniperus have narrow leaves and make excellent hedges that rarely need more than one pruning; usually in early spring a follow up pruning in autumn is sometimes required in temperate areas.  Spruce and pine should not be cut further then the current year’s growth – prune back only part of the current growth each year. Viburnum and buckthorn are easily shaped into an arch.

Preparing the Site
The secret to a successful hedge is correct soil preparation. Once you have decided where the replacement hedge is to grow set up a string line to mark the planting positions. Dig a trench along the entire length, and add well rotted organic matter to the soil. Leave for a month or so to allow the soil to settle before planting.

To establish a straight hedge, set up a string line and dig a trench along the length of the proposed hedge. Improve the soil with organic matter and fertiliser. Plant the shrubs/trees at the desired intervals, then water and mulch.

Depending on the size (and species) of the new plants, training should be started immediately:

  • Cut back about 1/3 of the growth to encourage dense, new growth. 
  • Trim the plants lightly to maintain shape and density but wait until the second year before giving another hard prune (ie. removing 1/3 off the height). 
  • Once the hedge has reached the desired height, trim it two or three times each season. This is especially important for conifers, which need regular light trimming rather than hard cutting.

Spacing Plants
Work out how many plants  are needed – the spacings will be much closer than is normally recommended for plants grown in the open; for example, small-leaved box and lavender are spaced about 30 cm apart and Leyland cypress about 75 cm apart.

Hedge Trimming

  • Put pegs in at either end, stretch a string line at the desired height then trim to the line to ensure a straight edge.
  • Line up the edge with an object at the end of the hedge
  • Mark a line on the ground at the hedge base with lime.
  • Cut a little bit at a time, stand back, evaluate, and only then cut more. (You can always take more off, but you can’t put it back after removing it!)
The base of the hedge should be clipped slightly broader than the top, with an even taper from the bottom to the top. This allows better light penetration to the lower parts of the hedge, resulting in more even foliage growth.

Rejuvenating Old and Overgrown Hedges
Problems with an old neglected hedge include:

  • It has grown too tall and wide taking up more garden space then originally allocated
  • It is casting excessive shade 
  • It has become thin and has gaps at the base with bare, exposed trunks. 
  • It has died out in parts.

The main methods of rejuvenating neglected hedges are:

  • Trimming – side trimming encourage thickening. In early spring cut back tops and side branches to within 20cm of the desired height and width. With this method however new growth will create a visual line between it and old growth.
  • Coppicing – usually only done every 6 years or so to rejuvenate certain species - all growth is cut down to 75mm (3 in) above ground level and left to re-grow 
  • Gapping up - a hedge sometimes deteriorates over time and gaps need replanting. Clear gaps and cut adjoining plants back to healthy vegetation. Dig in well-rotted manure, otherwise new plants will not grow in an old hedge. Plant new plants at 500mm (18 in) spacings ie. hawthorn, blackthorn or beech. 
  • Gradual rejuvenation – over a 3 to 4 year period. Each year cut back one- quarter to one-third of the oldest tallest stems to near ground level (leaving about 5cms). 

How Will You Benefit?

  • Learn to redevelop old gardens in sympathy with their past
  • Indulge a passion for historic gardens - know and understand more about our horticultural past
  • Fast track business or employment opportunities in landscape renovation
  • Save money and time -no traveling to classes
  • Determine when, where and how long your study sessions are, for yourself
  • More support than most colleges - we have a whole team of horticulturists spread across Australia, England and beyond; accessed whenever you need them, via email, phone or online chat.
  • Make better decisions about the building, management and care of old landscapes
  • Become increasingly aware of opportunities in garden renovation

Employment Opportunities

  • Start your own business as a landscaper and/or gardener
  • Specialise in garden renovation and reconstruction
  • Renovate historic gardens in sympathy with the architecture and their original design
  • Broaden your knowledge and skills for work in garden design and property renovation
  • Work in a plant nursery or garden centre as an in house expert
  • Research, write or lecture on historic gardens
  • Broaden your knowledge as a horticulturist or gardener


UK Register of Learning Providers, UK PRN10000112

Our principal John Mason is a fellow of the Chartered Institute of Horticulture

Accredited ACS Global Partner

ACS Distance Education is a member of the Australian Garden Council, Our Principal John Mason is a board member of the Australian Garden Council

Member of the Nursery and Garden Industry Association since 1993

ACS is a silver sponsor of the AIH. The principal, John Mason, is a fellow. ACS certificate students are offered a free membership for this leading professional body.Provider.

Member of Study Gold Coast

Institute of Training and Occupational Learning (UK)

Principal John Mason is a member of Parks and Leisure Australia since 1974 and a fellow since 1998

Recognised since 1999 by IARC

Course Contributors

The following academics were involved in the development and/or updating of this course.

John Mason (Horticulturist)

Parks Manager, Nurseryman, Landscape Designer, Garden Writer and Consultant.
Over 40 years experience; working in Victoria, Queensland and the UK.
He is one of the most widely published garden writers in the world; author of more than 70 books and edito

Gavin Cole (Horticulturist)

Gavin started his career studying building and construction in the early 80's. Those experiences have provided a very solid foundation for his later work in landscaping. In 1988 he completed a B.Sc. and a few years later a Certificate in Garden Design. I

Bob James (Horticulturist)

Bob has over 50 years of experience in horticulture across both production sectors (Crops and nursery) and amenity sectors of the industry.
He holds a Diploma in Agriculture and Degree in Horticulture from the University of Queensland; as well as a Maste

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