Wick Gardening
What are wicking garden beds?
The wicking system has been around for many years. People grow African violets this way. They place a wick at the bottom of a pot, the water moves up the wick and keeps the pot moist. This system is also found in self watering pots. Water is stored at the bottomg and moves upwards through the soil.
I will cover several different wicking systems. The conventional raised wick garden beds, my designed sunken wick garden beds, crate wicks, container wicks and wicking bath tubs.
I have experimented with wicking garden beds for several years, through all of the seasons.There are a few principles that will ensure the wicking system is effective.
I will cover several different wicking systems. The conventional raised wick garden beds, my designed sunken wick garden beds, crate wicks, container wicks and wicking bath tubs.
I have experimented with wicking garden beds for several years, through all of the seasons.There are a few principles that will ensure the wicking system is effective.
- The soil depth must be a minimum of 30cm deep, shallower soil or potting mix will be constantly water logged. This creates an acidic and putrid condition without oxygen, which does not support most plant growth.
- The initial soil must have lots of organic matter to absorb the water and increases it water holding capacity.
- There must be two overflow pipes, one at the bottom of the container to flush to stagnant water and accumulated salts. The other pipe is to ensure the water is flushed out below the soil level to prevent waterlogging.
- Water needs to be flushed out periodically, once a month. In wicking garden beds the flush pipe can be left open during heavy rains. In container wicks, placed the container on its side to drain the water.
- It is still important to mulch the water surface to reduce evaporation.
- Grow mineral accumulators in your wicking bed to help absorb the salts, these are borage, comfrey and most of your weeds such as dandelions.
Benefits of Wick Gardening
The wicking beds are more expensive and take more time to construct, however the benefits outweigh the negatives. The wick garden beds offer many benefits over normal garden beds.
The wicking garden beds are suitable for annuals and not for perennials such as raspberries or other cane.
- The wicked raised garden beds can be built on top of poor soil.
- There is less watering maintenance, as water is stored under the plant roots.
- The vegetables have a higher chance of survival during intense hot summer conditions.
- The raised bed become warm faster than normal garden beds, to allow vegetables to grow more quickly in spring and longer in autumn.
- The vegetables remain alive over the holidays and need less care.
- Nutrient is not loss to the subsoil when the garden bed is watered.
- The wicking garden bed are ideal for heavy feeders and quick climbers, such as corn, pumpkin, cucumbers and gourd.
- The wicking system can be adapted for aquaponic systems, where the water is constantly flowing in the gravel or clay material.
The wicking garden beds are suitable for annuals and not for perennials such as raspberries or other cane.
Raised Wicking Garden Beds
The raised garden bed is constructed conventionally using either eco treated pine sleepers, red gum or cypress sleepers. Builders plastic (200um) is placed the bottom of the raised garden beds and lined up the walls.
A slotted agricultural pipe is placed diagonally or can be zig zag if the bed is larger. The length must reach up the side of the bed. Make sure to hold the pipe down as the layer of materials such as sand or fine scoria is placed at the bottom. This will hold the water. Drill a hole at the same level as the medium (scoria or sand), this can be 25mm and slide in a pvc pipe. Cover the inside pipe with a small piece of shade cloth to prevent any of the medium from flowing out. This is the overflow pipe so the bed does not become water logged, from over watering of excessive rainfall.
Create ridges at the bottom to ensure water is accessible even when the water level falls below the overflow pipe. Shade cloth is placed on top of the material to act as a barrier between the soil. Water will move upwards through capillary action to the plant roots. This process minimizes evaporation as there is very little water directly exposed to the air. Place layers of good garden soil, manures, sprinkling of ash or lime and a layer of lucerne straw. Repeat this layer process until the soil is 5cm from the top. Cover with mulch and plant seedlings. The first watering will be over the soil, future watering can be through the agricultural pipe. There must be a minimum of 30cm soil to store enough water in the soil itself.
The raised wick beds can be constructed on concrete, hard clay or very sandy soils. There is minimal digging in to the existing soil base and can be moved to another location.
A slotted agricultural pipe is placed diagonally or can be zig zag if the bed is larger. The length must reach up the side of the bed. Make sure to hold the pipe down as the layer of materials such as sand or fine scoria is placed at the bottom. This will hold the water. Drill a hole at the same level as the medium (scoria or sand), this can be 25mm and slide in a pvc pipe. Cover the inside pipe with a small piece of shade cloth to prevent any of the medium from flowing out. This is the overflow pipe so the bed does not become water logged, from over watering of excessive rainfall.
Create ridges at the bottom to ensure water is accessible even when the water level falls below the overflow pipe. Shade cloth is placed on top of the material to act as a barrier between the soil. Water will move upwards through capillary action to the plant roots. This process minimizes evaporation as there is very little water directly exposed to the air. Place layers of good garden soil, manures, sprinkling of ash or lime and a layer of lucerne straw. Repeat this layer process until the soil is 5cm from the top. Cover with mulch and plant seedlings. The first watering will be over the soil, future watering can be through the agricultural pipe. There must be a minimum of 30cm soil to store enough water in the soil itself.
The raised wick beds can be constructed on concrete, hard clay or very sandy soils. There is minimal digging in to the existing soil base and can be moved to another location.
Sunken Wick Garden Beds
A conventional garden bed is usually raised and needs constant watering during the summer period. Sunken garden beds harvested run-off water from the surrounding area and directs it into the garden bed. The sunken garden bed can be combined with wicking bed systems to create a low maintenance, self watering garden bed. Wick garden beds rely on the process of capillary action (small spacing between the particles that draw water upwards). There is a layer of water underneath the garden bed with a material such as fine scoria or sand. There is initial digging to create the trench for the garden bed but it looks after itself by passively harvesting excess run-off water.
Firstly, you will need to decide where you want the garden bed and mark out the area. For our design we dug out as a large trench hole about 20cm deep. The bottom was made as level as possible. Use a level or pour water in the trench, water will find its own level. This was lined with builder plastic up to the ground level. A 10cm deep layer of sand was placed on the bottom. Shade cloth can be placed on the top. Layers of garden soil, manure, fire ash or lime and lucerne straw are placed on top until it reaches 30cm above the sand. Mulch is placed on top and it can be planted out. The garden bed is watered from the top. Extra soil will need to be added as it will settle over time. A drainage trench needs to be dug on the lower slope to drain excess water to prevent water logging and accumulated salts
It is important for the soil layer to be greater than 30cm to maintain enough soil moisture or it will dry out quickly. This has been learnt from different sunken bed designs. Old logs can be placed at the edge to raise the soil depth. A shallow depression was added along the upper part of the bed to increase the direct water catchment into the garden bed. Our sunken bed have proven itself to be worth the trouble of digging into the poor gravel and clay soil, where not much will grow. It passively harvests any heavy rainfall that runs of the slope.
Firstly, you will need to decide where you want the garden bed and mark out the area. For our design we dug out as a large trench hole about 20cm deep. The bottom was made as level as possible. Use a level or pour water in the trench, water will find its own level. This was lined with builder plastic up to the ground level. A 10cm deep layer of sand was placed on the bottom. Shade cloth can be placed on the top. Layers of garden soil, manure, fire ash or lime and lucerne straw are placed on top until it reaches 30cm above the sand. Mulch is placed on top and it can be planted out. The garden bed is watered from the top. Extra soil will need to be added as it will settle over time. A drainage trench needs to be dug on the lower slope to drain excess water to prevent water logging and accumulated salts
It is important for the soil layer to be greater than 30cm to maintain enough soil moisture or it will dry out quickly. This has been learnt from different sunken bed designs. Old logs can be placed at the edge to raise the soil depth. A shallow depression was added along the upper part of the bed to increase the direct water catchment into the garden bed. Our sunken bed have proven itself to be worth the trouble of digging into the poor gravel and clay soil, where not much will grow. It passively harvests any heavy rainfall that runs of the slope.
Container Wicking
Container gardening is useful for those with limited growing space, either a small garden or balcony. There are many commercial self watering pots for sale but you can make your own for a fraction of the price. You can buy the heavy duty containers without lids, not the cheap ones with lids. A cheaper option is to ask for the broccoli boxes from the green grocer, without the lids.
Place wood chips on the bottom, at least 4cm depth. Now place a 10cm length of 20mm pvc pipe at the wood chip level inside the container, and push a hole through the styrofoam box. Place a small piece of shade cloth to cover the small pvc pipe and push from outside the box. Apply shade cloth on top of the wood chip and fill with rich potting mix with compost. You can now plant your vegetables. We use these to raise seedlings in summer as there is a high water carrying capacity and seedlings do not dry out.
The slotted Agriculture pipe is not necessary for a small container but can be used as an educational demonstration.
Place wood chips on the bottom, at least 4cm depth. Now place a 10cm length of 20mm pvc pipe at the wood chip level inside the container, and push a hole through the styrofoam box. Place a small piece of shade cloth to cover the small pvc pipe and push from outside the box. Apply shade cloth on top of the wood chip and fill with rich potting mix with compost. You can now plant your vegetables. We use these to raise seedlings in summer as there is a high water carrying capacity and seedlings do not dry out.
The slotted Agriculture pipe is not necessary for a small container but can be used as an educational demonstration.
Wicking Worm Bath Tub
This alternative design uses a recycled bath tub. The same process is followed for making the wicking system, with extra plumbing required.
