What is wicking?
Wicking is the movement of water by ‘capillary action’, where water is drawn upwards due to surface tension and the interaction of adhesive and cohesive forces. This is what allows plants to draw up water and nutrients through their roots and up into the trunk and leaves of the plant.
In wicking beds, water is drawn up into the pore spaces in the soil to a height of about 350mm. Water wicking beds eliminate the problem of deciding when and how much to water. Plants in a wicking bed can last up to 4 weeks without additional watering, in contrast to surface watering, which can require daily watering depending on climatic conditions. Apart from the frequency of watering, there is a substantial saving of water itself in using the wicking method.
The video below shows how WaterUps are used to create a highly efficient wicking bed.
The history of wicking
In Australia, we use the terms “wicking” and “wicking beds”. In America, they use the terms “sub-irrigation” and “sub-irrigated pots” or SIP’s. Water wicking is not, however, a new invention. Wicking has occurred naturally on earth since rivers first formed. Archaeological evidence of gardens irrigated by capillary action dates back about 2,500 years to near the City of Old Jerusalem. In more modern times, utilisation of wicking for plant watering can be traced back to Ohio USA in the 1890s.
‘Popular Mechanics’ magazine in 1909 made mention of a “Self Watering Flower Box” that “protects plants from neglect”. The sketch in the article on the left shows an inlet pipe and a water reservoir very similar in design to those seen today. A patent was actually granted in the United States in 1917 for a sub-irrigation planter. In Australia, where water is a scarce resource due to our climatic conditions and sometimes harsh growing environments, the application of wicking beds in organic agriculture is fast becoming a popular method to help grow plants and keep them healthy.
However, until WaterUps launched its wicking cell, all “wicking” and “sub-irrigation” applications were inbuilt in planters. WaterUps is the first product that has allowed this well-proven concept to be applied to virtually any plant watering environment, because of its modular design.
WaterUps Installation Basics
WaterUps wicking systems can be installed in existing garden beds or in WaterUps design wicking beds and planters.
Introduction to the WaterUps System
WaterUps wicking systems are easy to install. Click this video for a basic introduction to wicking and WaterUps installation.
The WaterUps Oasis 1680 bed
Click this video for a step by step guide to the assembly and operation of the WaterUps® Oasis 1680 wicking bed.
WaterUps Wicking Products
What are the WaterUps cells made from?
WaterUps cells are manufactured from recycled polypropylene (‘RPP’) raw material.
Where are WaterUps manufactured?
WaterUps cells are manufactured in Australia in Western Sydney.
What if the WaterUps inlet pipe is too short for my wicking bed?
The best way to extend the inlet pipe is to cut it in half and insert a piece of 50mm poly pipe in the middle.
What if I can’t attach the WaterUps Overflow Pipe?
If you have had to cut the cells to fit your bed and can’t position an overflow pipe in the corner slot of the cell, simply cut off part of the rectangular piece that attaches to the cell. Make sure that you retain the short end piece of the rectangle that connects to the screw thread.
How many WaterUps cells will I need?
To work out how many WaterUps cells you will need we suggest that you use the calculator tool on our website which you can go to using the link below.
GeoTextile (‘GeoTec’) Fabric
When would GeoTec fabric be required?
It can be used for the following purposes:-
- To protect against possible root intrusion from under the base of the bed;
- To cover any gaps between the edges of the WaterUps cells and the internal walls of the bed in order to prevent soil from getting into the water reservoir;
- To cover any gaps caused by cutting a WaterUps cell. This is particularly important if you have to cut through any of the feet or ʻwicksʼ; and
- If you intend to put a plant with an aggressive root system in your new garden bed, it is recommended that you put a layer of GeoTec over the top of the WaterUps cells and slightly up the walls.
Soil & Potting Mix
How much soil mix is needed for my WaterUps Wicking Bed?
To work out how much potting mix/soil you will need we suggest that you use the calculator tool on our website. Leave 25cm to allow for a layer of mulch. This will provide quantities of both bulk and bagged mixes. While you can expect that the potting mix will compact slightly after initial installation, this will be more than offset by the volume of the soil/root base of the plants used in the bed.
What is the optimal soil mix for a wicking bed?
Unlike river sand/scoria/gravel based wicking beds, WaterUps wicking beds do not require a sandy soil mix. The optimal mix is ultimately dependent on what is to be planted. However, as a general rule, the mix should contain up to 50% by volume of organic matter. Mushroom compost should be included to enhance the soil structure.
What tools may be needed to install my WaterUps wicking system?
A detailed list of the tools & equipment you may need to construct your WaterUps wicking bed is contained in the WaterUps Installation Guide and the specific DIY Installation Guide relevant to the type of WaterUps wicking bed you are constructing. Generally, however, you will likely need the following items:-
- 18mm Hole Saw or Speed Bore – to drill the hole in the wall of the raised bed for the overflow pipe;
- Jigsaw or Hand Saw – to cut the WaterUps cells to fit the existing walls of the raised bed;
- Cable Ties – to secure the long overflow pipe to the WaterUps cell when installing timber beds; and
- Staple gun or Gaffer Tape – to hold the pond liner in place while adding the cells if you are not using one of our WaterUps Reservoir Liners.
Do I need to add anything to the soil/potting mix to help the wicking process?
We recommend that you fill each of the ʻwicksʼ, which are the 4 feet at the base of each WaterUps cell, with Perlite. The addition of Perlite to the wicks will improve the wicking process.
Can I use Vermiculite instead of Perlite?
We do not recommend using Vermiculite in the ʻwicksʼ. While both minerals are widely used to improve the soil structure, Perlite helps by creating air pockets to improve capillary action/wicking and the growth of a healthy root system. Vermiculite is used more for water retention as it can hold many times its own weight in water. Perlite is hard and highly porous, while Vermiculite is soil and spongy. Vermiculite may be useful towards the top of your soil to help moisture retention.
How much Perlite do I need?
You will need approx. 2 litres per cell. To work out how much Perlite you will need, we suggest that you use the calculator tool on our website.
How much water does a WaterUps wicking bed hold?
When full, there will be 120 litres per square metre of water in your WaterUps wicking bed.
How do I water my WaterUps wicking bed?
To water your WaterUps wicking bed simply insert the hose into the inlet pipe and fill the reservoir until water starts flowing out of the overflow pipe.
How often will I need to refill the reservoir with water?
This will depend on what plants you are growing, the time of year, and the amount of natural rainfall that you experience. However, in our experience, periods of up to 4 weeks are achievable before you will need to refill your WaterUps wicking bed. It is recommended that you allow the water level in your WaterUps wicking bed to go down to at least 1/4 full before refilling. This will assist soil aeration.
How do I tell how much water is in the reservoir?
You can use a dipstick or set up a moisture sensor system.
Soil Depth in Wicking Beds
What is the optimal depth of soil in a wicking bed?
For optimal “wickability” the soil depth should be approximately 300mm to 350mm. However, this can vary depending on what you are growing. The depth of the root system of the plant that you are putting in the wicking bed is also relevant. For example:
- 15cm to 20cm soil depth for herbs, lettuce and seedlings;
- 30cm to 35cm soil depth for woody perennials, deeper rooting vegetables and ornamentals; and
- 40cm to 45cm soil depth for citrus trees, stone fruits, pome fruits, and large shrubs that have a root ball of approx 20cm.
What should I do with newly planted seedlings?
After planting seedlings it is important that you add a layer of mulch to the top, and that you water the bed normally with a hose or watering can for the first couple of days after planting while the roots of the seedlings become established.
Why use WaterUps?
Commercial and Civil Works
Architects and Landscape Designers are now starting to focus much more on sustainability in design. WaterUps® can play an important role in this move to more sustainable planning by helping us save water and make urban greenspaces easier to maintain.
- Roof Garden, Hobart TAS
Award-winning architect Ryan Strating’s Core Collective designed this amazing roof garden in Hobart, Tasmania. Given the exposed position and limited access for maintenance, Ryan wanted this garden to be largely able to look after itself. Following advice from Angus Stewart, he decided to use WaterUps Sub-Irrigation Channels. Five months later in Nov 2021, the results speak for themselves.
- Commercial facility. Yagoona NSW
WaterUps wicking systems were installed at this facility in 2021 in order to achieve permanent green spaces with minimal maintenance.
Schools & ELCs
“Creating and maintaining gardens helps students to develop knowledge and skills for sustainable living, and for studying how we can meet human needs while preserving the environment for future generations. Practical activities in garden design, planting and harvesting, can be linked to a range of curriculum areas including science, arts, literacy, and numeracy.”
School and ELC Projects
- Trinity Grammar School, Summer Hill NSW
In mid-2021 WaterUps® worked with Landscape Architecture lecturer at UNSW, Melinda Bargwanna, to help establish an amazing array of wicking garden beds for growing edibles in various areas of the junior school. These will be central to the sustainability curriculum that Meinda will be running at Trinity.
- Broderick Gillawarna School, Revesby NSW
In June 2020 we assisted with the installation of a number of our Oasis steel wicking beds at Broderick Gillawarna, a special education school for students with disabilities.