Episode: Five
Date: 5th April 2008
Presenter:  Nigel Ruck
Story Title: Mitre10 Project Planners- Hedging and Screening Plants

This week Nigel Ruck flew into Perth to help out the good folks at Ronald McDonald House. As part of an ongoing project he planted out some screening plants to offer some privacy from passing traffic. The three plants he used were Gardenia ‘Golden Magic’, orange jessamine (Murraya paniculata) and the pride of Bolivia tree (Tipuana tipu).

The project was based on the soon to be released new Mitreplan from Mitre 10 as seen below.

Hedging and Screening Plants
Using plants for screening and hedging is a practise as old as gardening itself. In modern day gardens the practise is used for two main purposes; aesthetics and protection.
Hedging plants differ slightly from screening plants in that they are usually plants clipped and preened to pre-determined heights and widths. Screening plants are less formal and tend to be maintained much less. In regards to the garden they both serve the purpose of offering protection, hedging plants are also a very aesthetically pleasing and integral to many garden designs.

For years Australian gardeners would only ever plant out hedging and screening plants if they wished to block out the neighbours. In recent years with water restrictions and declining mains water resources the benefits of hedging and screening in regards to water efficient gardening has become more apparent. Hedging and screening plants offer protection from hot drying winds and to help create micro-climates in your garden.

A well placed hedge can look structural, regal and offer a great backdrop to the rest of your garden. They can be included in any type of garden design from formal to cottage to minimalist and work fantastically within a garden to define separate garden beds and other parts of the garden. Screening plants tend to be less formal but can still look fantastic. They will generally be planted to offer protection, but with the right plant choices they can look great.

Aspect
Before you even pick out any hedging or screening plants it is important to determine all aspects of the area. Understanding the weather patterns of your local area will help determine the right plants for the job. You may find that the area you wish to plant out is subject to drying winds in the summer but if your plants are too tall they could block out your winter sun. Some areas, particularly close to the coast are subject to a constant battering from winds where a single row of screening plants alone will just not offer enough protection. 

Soil Improvement
Most plants benefit from a nutrient rich soil which they can sink their roots into; hedging and screening plants are no different. A good strong root system is not only essential for supplying your plant with water and nutrients. Your plants’ root system also serves as an anchor for your plants, which is important when you are using plants in wind blown conditions. A good strong root system will ensure your screening plants are happy and healthy and will not blow over at the first sign of rough weather.

Spacing
How much space you will need for your plants will very much depend on the types of plants you are using. Wherever possible try to allow the plants some space to grow into. Many plants can be trimmed to a consistent 30cm width but they will perform much better if they are allowed to grow to their natural one or two metre width. The distance between your plants will also vary but will often be determined by your budget. The closer you plant your plants together the quicker they will join together and create your screen or hedge. Obviously the more plants you use the more money you will need to spend.

Ideally you should space your plants around one third of the eventual hedge height. As an example if your screen is going to be kept at three metres high, space your plants at one metre intervals. It is also important to consider how much space you are going to need to maintain your plants. Regular trimming can become a very difficult task if you only allow yourself a few centimetres of space between your house and your hedge.

Choosing the right plants
When choosing plants for screening it is important to fully understand why you want a hedging or screening plant. In all but a few cases, you will want the plant to grow quickly and have a thick dense habit. It is important to note that some plants such as wattles can grow very quickly but can be short-lived; therefore your wonderful hedge that has grown to fence height within a year has then died off in the next two years meaning you have to start again. Other plants such as some conifers and plants like the Bay Tree create a very thick canopy but can take many years to reach their full maturity. By understanding your needs fully you will be able to determine whether the plants are required for a short term or long term and choose plants accordingly.

Whether you need to have a plant with a thick dense habit will be determined by the needs of the planting. If you are aiming to offer privacy from neighbours or relief from the noise of passing traffic a thick dense hedge is the way to go. Plants like conifers, gardenias, sasanqua camellias, lilly pillies, orange jessamine and viburnum tinus have a naturally tight compact growth habit. Other plants like deciduous trees and some natives are great as screening plants to reduce the intensity of strong winds but offer less in the way of privacy.

Irrigating your plants
A good strong root system is imperative with hedging and screening plants. It is much better to give your plants a good watering once a week and encourage their roots to go deep into the soil instead of a watering a little at a time on a regular basis. Sub surface irrigation, which is placed under mulch, is the easiest option for screening and hedging plants. It can be run in straight lines along side the plants and delivers water much more efficiently than traditional reticulation systems.

Caring for your plants
Most hedging and screening plants will benefit from regular pruning and feeding. A regular trim will, in most cases, encourage fresh new growth creating a thicker, bushier hedge or screen. Most evergreen plants prefer to be pruned after flowering and most deciduous plants prefer to be pruned in the winter, check with your friendly Mitre 10 horticulturalist to find out when your plants prefer to be pruned.
Regular feeding will encourage strong growth; look for fertilisers which are high in nitrogen for leaf and foliage growth and phosphorus for root growth.

Great plants for hedging and screening
There is a huge range of plants to suit all of your hedging and screening requirements. Ask your local Mitre 10 horticulturalist the best species from the following varities to suit your needs;  boxes, gardenias, orange jessamine, New Zealand Christmas bush, camellias, conifers, pittosporums, viburnums, lily pillies, grevilleas, bottlebrushes, leptospermums, hibiscus, mirror bush, African box, dwarf nandina, euonymus, plumbago, westringia, myrtles, rosemary, lavender.

The list of plants suitable for hedging and planting is wide and varied; it is also getting larger every year. Many plant breeders have seen the popularity of hedging plants and have therefore been breeding new variations of old plants for years. Your local Mitre 10 store will be able to show you these new varities and make sure you can grow the best hedge or screen possible.