5 tips for Drought Tolerant Landscaping in Melbourne

To understand Drought Tolerant landscaping, we need to first understand some of the technical terms in the world of soil chemistry and how that affects drought tolerance.

“Plant Available Water” “PAW” Is the amount of water in the soil that is available for the plants and is between the water capacity and the plant wilting point or crop lower limit.
“Plant Available Water Capacity” PAWC is the maximum amount of moisture that can a particular soil can hold.

1. Organic Matter helps drought tolerant landscaping.

Whether you have a clay soil or a sandy soil, your garden will benefit from organic matter. The soils ability to hold moisture will increase with the addition of organic matter. The additional organic matter works in two way. Firstly, organic matter has a higher water holding capacity than mineral soils. Secondly, the organic matter improves the soil structure allowing moisture to pass through the soil to the plant roots. In some cases, doubling the amount of organic matter in the soil can result in around 25% more water storage capacity.

*Drought tolerant landscaping and the effect of organic matter. Increasing organic matter increases the amount of moisture that can be stored in the soil.*

Soil Texture and Composition

Soil texture and composition also has a big effect on water storage capacity. Sandy soils with low percentage of clay and low percentage of organic matter are very poor at storing moisture.

Soil texture and the amount of moisture that can be stored in the soil. — *The relationship between soil texture and the amount of moisture that can be stored in the soil.*

Imported Topsoils

Often Imported Topsoils, purchased to landscape your garden, will be sandy loams. These are great soils for high traffic lawn areas, especially for the top 50mm of soil. If using imported topsoil for garden beds, mix the soil with some of the existing soils by cultivation of the subsoil to boost the clay content. This can also be done with the subsoil layers of the lawn areas. Also, order Imported Topsoils with a good percentage of organic matter included in the mix. Always use imported topsoil to Australian Standard (AS4419 Soils for Landscaping & Garden Use) and use mixes with higher levels of organic matter for garden beds.

The Effect of Clay in your garden soil

Clay soils can hold much more moisture than sandy soils. The fine clay particles are less than 2 microns, but there are so many clay particles in clay soils that the total surface area is much higher. The fine particles however, make it more difficult for the plant roots to penetrate the soil to extract the moisture. This results in the increase in the plant wilting point in high clay soils. Again, organic matter will help improve the texture of the soil so that roots can penetrate to access the moisture. If you have a reactive clay soil, then cultivating gypsum into the soil will also help.

Negatively charged clay particles repel each other. — *Negatively charged clay particles repel each other*

2. Mulch

According to a study by the University of Florida, mulch can reduce water losses by evaporation by up to 30%. Mulch however, does much more than just reduce evaporation. By rotting down into the topsoil, mulch adds to the organic matter in the top layer of soil. Mulch also greatly reduces erosion of the topsoil and helps to keep plant roots cooler by reducing the sun’s heat radiation into the lower layers of the topsoil. Mulch also plays a role in suppressing weeds, but if weeds do grow, they are much easier to remove.

*Using Mulch for Drought Tolerant Landscaping. Mulch also reduces erosion and weed growth as well as adding to the organic matter as it rots down.*

Groundcovers

Groundcover plants can play a similar role to mulch in reducing the heat penetration into the soil and reducing evaporation from the soil.

*Myoporum parvifolium or creeping boobialla is a ground cover that makes life difficult for weeds.*

3. Drip Irrigation System

There was a time when an irrigation system meant garden sprinklers spraying huge amounts of water everywhere. This led to a great deal of wasted water with much of the spray landing on paths and driveways. Evaporation of the water from the surface of the garden was another cause of waste. Modern computer controlled closed loop drip irrigation systems are much more efficient. With modern irrigation systems, water be delivered directly to the root tips.

*Drought tolerant landscaping - Irrigation drip system delivers water to the right place.*

Water supplied to where it is most needed.

The plant uses osmosis to absorb water from the soil. The root hair cells, which are mostly near the root tips, are adapted for taking up both water and mineral ions. Part of this adaption is the large surface area of the root hairs exposed to the soil. Older root hairs tend to die off, so most of the living root hairs are concentrated near the root tips. Placing the irrigation drippers near the root tips means that water can be absorbed more efficiently.

*Drought tolerant Landscaping - Osmosis and transpiration. The Root hairs near the tips take up the water and nutrients.*

Closed loop computer control irrigation systems

Modern computer-controlled systems use feedback from remotes sensors to determine the water requirements for plants on each channel. Depending on the systems, sensor measure soil moisture, temperature, humidity and rainfall to estimate plant water requirements. Some new commercial irrigation systems in agriculture are using Artificial Intelligence or Machine Learning to irrigate crops more efficiently.

4. Drought Tolerant Plants

Many plants have evolved to cope with dry conditions or the occasional drought. This includes many Australian Native Plants, Mediterranean Garden plants or plants from the dry parts of America and especially Mexico.

Drought tolerant Australian Native Plants

Amongst the Australian Native plants, Xanthorrhoea (Grass Tree) and Anigozanthos (Kangaroo Paw) have outstanding ability to survive in dry sandy soils.

*Australian yellow kangaroo paw flower (Anigozanthos pulcherrimus) in front of a grasstree*

There are also many Australian Native grasses like Lomandra that are great for dry conditions. Our favourite plants dry conditions in Melbourne gardens are the following;

Star Jasmine (Trachelospermum jasminoides) – The Star Jasmine is moderately drought tolerant once it gets established. This evergreen climbing plant can be grown either as a vine, that can grow to more than 6 metres high, or as a ground cover. It can be grown in either partial shade of full sun.

Climbing Fig (Ficus pumila) – The fast growing climbing fig is tolerant to salt spray, drought and partial shade. This makes it a great plant for coastal gardens in suburbs like Hampton. It will grow to more than 5 metres under ideal conditions and can also be grown as a ground cover.

Waterhousia Floribunda or Weeping Lilly Pilly – Generally, the Lilly Pilly is a hardy and drought tolerant hedging or screening plant once it is fully established. It is a great Australian native alternative to the buxus hedge or Murraya. Despite being a rainforest plant, Waterhousia floribunda will survive a few dry spells once it is fully established. This is one of our favourite Australian drought tolerant plants.

*Weeping Lilly Pilly Waterhousia floribunda*

Salvias like Salvia Leucantha (Mexican Sage Bush) are generally very drought tolerant. There are only a couple of salvia varieties that are not drought tolerant. The Leucantha is an Autumn flowering perennial which can add colour to your Melbourne garden in early May. Salvias can handle subtropical as well as temperate climates. This makes them a good plant for temperate climates like Melbourne.

Salvia leucantha purple flowering shrub — *Salvia leucantha is a purple flowering shrub growing to around 1 metre tall.*

Lomandra Longifolia “tanika” is a hardy Australian Native grass that looks great and is tough as well as drought tolerant. With attractive blue-green foliage and yellow flowers in Spring, it is ideal for mass planting, but can also be planted in individual tufts.

The green lomandra makes a great contrast with this grey stone wall. — *The green lomandra mass planting makes a great contrast with this grey stone wall.*

Poa labillardierei (Common Tussock Grass) is another hardy Australian Native Grass. It will grow well in most soils, but will enjoy some moisture during summer. It can be cut back hard then heavily watered to create new growth. The long green leaves will turn a little silver in dry weather. It will flower from October to March with purple-green flowers.

https://youtu.be/T5UIRHXT6AI

5. Soil Wetting agents

The breakdown and decomposition of some organic matter will result in a waxy coating on some soil particles. This makes the soil hydrophobic. This is much more prevalent on sandy soils than clay soils. The obvious solution is to treat the garden with a surfactant or wetting agent before rain.

Hydrophobic versus hydrophilic — *Drought Tolerant Landscaping hydrophobic-hydrophilic*

A less obvious solution is to spread a little garden lime on the hydrophobic soil. The garden lime will do two things. Firstly, the increased PH will encourage bacteria that will break down the waxy material. Secondly, it will add fine particles to the soil. Some types of clay are also useful for reducing surface tension in the water droplets.

Drought Tolerant Plants in Commercial Landscaping

As part of the move towards greater sustainability, Landscape Architects and landscape designers are looking at methods to reduce fresh water consumption in commercial landscaping. These methods include rain gardens, blue roofs, rainwater storage with irrigation drip systems and, perhaps most importantly, drought tolerant Australian Native Plants.

Potted Plants for the commercial landscaping. — *Sustainable commercial landscaping using drought tolerant plants. Establishing smaller Australian native drought tolerant plants early will save you money and water.*

by callum

Coastal Garden Design

Melbourne Coastal Garden design

Melbourne Coastal Garden design, depends heavily on selecting the right plants for the conditions. Coastal garden plants have to endure salt spray, wind and often not very fertile sandy soils. If you have a home in one of Melbourne's beachside suburbs these home gardening tips will help you establish a great garden.

The coast is an area of land that connects the mainland to the sea and is continuously changed by the sea, wind and other natural factors. A coastal landscape is a region of coastline with various coastal characteristics, some of which are erosional and some of which are depositional. Compared to other coastal landscapes, it is distinguished by the dominant traits that shape the coastline there.

Coastal Landscapes - Reds Landscaping & Design — *Coastal Landscapes naturally consist of shifting sands blown by the wind.*

Coastal landscapes are simple, they flow, and their design speaks volumes by enhancing the natural beauty of their location.

Coastal gardens

Coastal and seaside gardens are areas of attractiveness, beauty and fascination where you can relax and enjoy the beauty of the sea. Natural factors along the seaside might produce an unfavourable atmosphere for the garden plant. Harsh wind, salt spray and sandy soil are the factors that might affect the growth of the landscape plant. Due to all these factors, coastal gardening is always a challenge for the gardeners and even the most skilled.

Coastal garden designs

As mentioned above that, coastal gardening is always a challenge for gardeners. The first challenge that comes to mind is what to plant. The key point in designing the coastal garden is selecting those plants that can handle and tolerate the strong wind and salt spray. Fortunately, if carefully selected, many ornamental flowers and plants can survive and thrive in such kinds of conditions. These plants can help you to design the perfect coastal landscape. Consider planting native coastal plants, flowers and grasses. These hardy plants are well suited and have the added benefits of helping to control erosion and providing a beaker from blowing sand.

Coastal garden designs ideas

Bringing all the important and suitable elements into your coastal design. The harsh elements of the Australian coast can be used to highlight the natural raw beauty of the Australian coastline. First of all, never forget to use suitable native plants and resilient materials in your garden to increase the overall look of the garden and survive in the salty air. This will enable you to spend more time relaxing in your coastal garden for many years and less time in maintenance.

Choosing the proper constructing materials for coastal garden design is very important to ensure that it achieves the style and can also resist the harsh conditions of Australia because the normal construction materials decay three times quicker in saline air. So use a hardwood like spotted gum for fire and moisture-resistant to prevent fading.

To enhance durability and reduce the environmental effect of the coastal garden design, many builders now propose decking materials manufactured from recycled plastic over natural timber because the natural timber decks deteriorate much quicker on the coast and require re-oiling quickly than the recommended time.

To fit the rough nature of the garden, you should always use raw natural materials as a feature of a beautiful coastal garden design. Huge blocks of sandstones, granite and large containers with seasonal flowers are carefully located all around the garden to create an earthy, coastal atmosphere. The addition of entertaining and dining spaces, seats, and fire pits can help you invite guests and friends with whom you can spend time in your coastal gardens.

Australian coastal Garden Designs

The Australian coastline is a harsh and remarkably attractive feature of the country’s natural landscape. Unlike a tropical garden, Australian coastal gardens are not lush and overgrown; instead, they are delicate and strong-willed and typically Australian in nature. Coastal gardens in Australia should be designed to tolerate the salty air and hot climate. Australian native plants have evolved to tolerate hard Australian conditions and are an important element of any coastal garden. The uniqueness of the Australian coastal gardens has a distinct character that is both harsh and extremely beautiful. They do not require lots of water or maintenance and don’t confuse with tropical.

Gardening on Sandy Soil

As we know, the coastline's soil is mostly sandy, which contains a maximum proportion of sand particles with little silt or clay. The sand particles are much larger, and the gaps between them are bigger, due to which water flows away quickly. They are dry and warm in spring. In sandy soil, most nutrients are washed out quickly. Phosphorus is usually retained, but nitrogen and potassium go easily. Due to these factors, gardening on sandy soil is challenging but not impossible. Here are some tips to improve the health of the sandy soil and grow a beautiful and lush green garden on it.

How to improve Sandy Soil?

The best sandy soil amendments increase the ability of the sandy soil to retain water and increase the nutrients in the soil as well. This can be done by improving the condition of the sandy soil, and the best way to do this is to frequently and regularly add organic matter to the soil. Layer in compost, wood chips, composted manure straw, shredded leaves, grass clipping and other mulches helps to improve the organic matter content of your soil. Studies showed that the addition of bio-fertilizer to sandy soil significantly increased the physical and chemical properties of the soil and the availability of the nutrients in the soil.

Soil Moisture - Reds Landscaping & Design — *The ability of your lawn soil to provide moisture will depend on the soil structure and the amount of organic matter.*

You can also improve the sandy soil by converting them into sandy loam soil. The sandy loam soil comprises 50-70 % sand, 20 % clay and 10-30% organic matter. Sandy loam soil is a very desirable soil for planting garden plants. This type of soil is popularly known for its excess water drainage property and nutrients contents.

Irrigation of sandy soil

Irrigation of sandy soil must be considered carefully. Irrigating sandy soil requires great attention to the timing and amount of irrigation water applied, which are crucial decisions for each operator. Because the water storage capacity of the sandy soil is low and the infiltration rate is high. Therefore regular but small irrigation is necessary for the sandy soil, mostly when it is shallow. Under sandy soil, drip and sprinkler irrigations are more suitable compared to surface irrigation. Because in these irrigation systems, water is applied more to the places of the plant root area, which increases the efficiency of water.

Drought tolerant plants

Some plants are drought resistant and can tolerate and enjoy the sandy soil. Usually, any plants native to coastal areas are a good option to try. Here are some best plants for your coastal garden because these plants thrive and survive in sandy soil.

Xanthorrhoea

Xanthorrhoea, or Grass tree, is one of the most well-known symbols of the Australian bush Australian coastal garden. It is a particularly Australian plant that represents the Australian landscape. It is drought resistant. This plant likes well-drained soil and full sun, which is ideal for a coastal garden.

Xanthorrhoea is a slow-growing plant that can grow up to 25 mm in one year. It is also known as a great pot plant. The grass tree is a great feature plant with a harsh beauty that is typically Australian.

Kangaroo Paw

Kangaroo Paw is one of the fascinating Australian plants due to its unique flowers and different colours. They grow from an underground rhizome and produce lovely flowers on long stems, usually during spring and summer. Kangaroo paw enjoys the harsh dry arid condition due to which this plant is ideal for sandy soil and coastal garden.

Lomandra

Lomandra Plant, commonly known as mat rushes, is a perennial, herbaceous monocot in the

Asparagaceae family. It is an elegant native grass growing in large rounded open tufts, like a green fountain or firework. This round, symmetrical shape makes them an ideal plant for gardening. This plant can thrive perfectly in coastline gardens. This plant can grow in most soils, from sandy to clay and is drought and cold tolerant.

Lomandra Longifolia Bush - Reds Landscaping & Design — *Lomandra are salt tolerant, performing well in coastal gardens*

Australia's diversified geography provides the ideal basis for a wide range of beautiful gardens. Australia is blessed to access a diverse range of unusual plants, whether on large national estates or in a well-planned and planted urban area.

Despite the harsh climatic condition, Australian loves gardening. They utilise their backyard with different landscaping ideas and convert it into beautiful gardens. Outdoor dining spaces, pergolas and evergreen plantings are just a few examples of these suburb gardens.

Melbourne Coastal Garden plant selection

Limonium Perezii

Limonium Perezii, features beautiful flowers and foliage which can be hacked back to reshoot. This plant flowers nearly year round with minimal water and care. Limoniums handle Australia’s coastal garden conditions and climate well and are an absolute must have for any ornamental garden. As you would expect for a plant native to the Canary Islands, these plants handle the coastal garden conditions very well, preferring a well-drained soil and full sun. These plants will also tolerate a moderate frost. The more than 120 plant that belong to the genus Limonium are often referred to as marsh rosemary or sea lavender, but they are not related to either lavender or rosemary. The small papery flowers can be dried and used in flower arrangements.

Viola Hederaceae - Reds Landscaping & Design — *Viola Hederaceae or Native Violet in an Australian native shrub that is ideal for your coastal garden.*

Banksia Robur

Banksia Robur or swamp Banksia growing up to two metres in the wild, this plant is a small tree or shrub with large flower spikes and fruits from autumn to winter. Despite its name, the swamp Banksia will thrive in a variety of soils and conditions. The large oval shaped serrated leaves can grow as large as 120mm by 400 mm long. This plant can be planted as a group for screening neighbours or by itself as a feature plant.

Xanthorrhoea Macronema

Xanthorrhoea Macronema or Coastal Grass Tree is a grass tree without a trunk but has a creamy flower spike around 1.5 metres long. The flower itself is around 45 to 140mm long.

Garden Maintenance for your Coastal Garden

Many coastal gardens are very sandy and the soils struggle to hold moisture and nutrients. One solution is to put some clay soil into a bucket of water. Stir this until the clay forms a suspension in the water. Pour this around your plants to help fill the gaps in the porous sandy soil. A fast decomposing mulch like pea straw, as well as organic fertilisers, will help.