Self Watering Earthbarrels
What makes Earthbarrels unique is their ability to grow plants/vegetables 4X times faster!!! This is not just an ordinary flower pot. The tomatoes in the picture with the Earthbarrels are over 8 feet tall.
Earthbarrels are perfect for your home patio, deck or small yard garden. You can grow tomatoes, cucumbers, beans, squash, peppers and so much more with earthbarrels with great results. Earthbarrels can be used for flower containers as well. They are great for our oregon climate because of the way it self-waters and self-fertilizes.
Earthbarrels are self watering containers which take the work out of gardening while providing healthier plants and more vegetables. While there are other Earthbarrels designs, Our goal was to remake plastic barrels into attractive planters which could be placed anywhere around your house to grow vegetables and flowers.
What is needed to make a Earthbarrel
55 gal plastic barrel - Earthbarrels are made from used barrels that are used to transport liquid products. They are great for growing plants and vegetables fast and effectively. These are made by hand and guaranteed to work for all your garden growing needs.
2 feet of landscape cloth
1 1/2" PVC pipe 20" long
4 zip ties
10 long aluminum rivets
3/4: bulkhead for barrel valve
You may use plastic spray paint to color the Earthbarrel, otherwise the Earthbarrel will be white or blue.
Use your artistic talent and make a unique Earthbarrel. The picture shows a white Earthbarrel sprayed using leaves and another Earthbarrel painted green.
The Secret of the Earthbarrel is that it uses - wicking.
Wicking is a way of growing plants in which water is wicked up from an water reservoir. The Earth Barrel has a 8 gallon water reservoir, 3 cubic feet of soil and 3.2 square feet of growing space.
The major advantages of the wicking are:
1. You do not have to water every day. You can fill the water reservoir when you feel like it.
2. Water useage is reduced by up to 50% over conventional watering.
3. Evaporation of water is significantly reduced.
4. Rain harvesting techniques can be used which mean free water.
5. Improve soil quality when worms are introduced.
6. Significant increase in production
Wicking is relatively inexpensive and easy to operate once the basic principles have been understood.
How does wicking work
To understand how wicking work we have to look at the characteristics of one of the most remarkable substances – water. The apparently simple water molecule H 2 O and it is polar - meaning that one end is positively charged while the other end is negatively charged. It is rather like a bar magnet with a North and South poles with each pole attracting the oppositely charged end of other molecules.
The net result is that water has a tensile strength. We see this in the way that water forms into drops. It is this tensile strength which pulls water up into the highest trees, as the water evaporated from the leaves it literally pulls water out of the soil through this extended chain. While individual water molecules have the strongest attraction for other water molecules they are also attracted to many other materials such as soil particles and organic materials. These surface tension forces or wicking forces are seen when water rises in capillary tubes.
Soil with large void
When water is applied to the soil surface it will initially fill the voids however water in the larger voids which cannot be held in place by surface tension will be pulled down by gravity so forming a wetting or flow front. When the water application stops the flow front will stabilize leaving the soil above the flow front being at field capacity. The total amount of water held in place by surface tension is called the field capacity. Soils with very fine particles can hold more water than soils with coarse particles, a good loamy soil may hold about 15%.
This pattern is generally true for the theoretical homogeneous soils, in practice soils are rarely that uniform containing many cracks or fissures which allow water to penetrate deeper without wetting out the soil beside the cracks.
The drying effect
Plants will extract the water from the soil starting with the water in the large pores near the surface. After a time this water will become more difficult to extract so the plant will now extract water from deeper in the soil. This gives what is in effect a drying effect. After a time the plant can no longer extract adequate water from the soil. There is still water in the soil but it is tightly locked into the smaller voids. Soils with fine particles may hold more water but this water is more difficult to extract. Soils with course particles will hold less water but it is easier for the plant to extract. The water available to the plant is generally only about 10% of the total volume of the soil.
Water holding capacity of a wicking Earthbarrel
The total void content of the wicking Earthbarrel soil may be 30% of the total volume so if the wicking soil is totally saturated with water then the volume of water held in the soil will be about 30% of the total volume or some double the field capacity. The essential feature of the wicking is an reservoir of water in immediate contact with the soil in the root zone. The Earthbarrel has a 27 gallon reservoir of water.
This water reservoir can be just water with wicks or filled with a coarse organic material which has a large void content and will offer less resistance to water being pulled out by surface tension from
layers above. This increase the readily available water several fold, and is an important feature of the wicking system.
Problem with surface watering
Surface irrigations are very inefficient. The water in the top surface layer will quickly evaporate and be lost leaving the soil dry.
At the next water application this dry soil will have to be wetted before any water enters the root zone. Typically the first 1/2 inch of water applied will be lost. This means that short frequent irrigations are very inefficient with significant loss of water. Deeper irrigation so the flow front just reaches the base of the roots is the most
efficient. However it is very difficult to know how much water to apply so the flow front just reaches the base of the roots.
Over irrigation so the water passes beyond the root zone waste water and can also cause environmental pollution. Water below the root zone
The soil in the root zone will become drier as the plants extract water. The small pores will create a tension trying to pull water up from below the root zone. However this tension will be resisted by surface tension and gravity. There may be sufficient pull to raise the water a small amount possibly 3/4 inch but in reality there is very little upward movement. Essentially any water passing beyond the root zone is effectively lost to the plant. This water may contain nutrients which will eventually enter the water tables and possibly river systems or water supplies.
The watering dilemma
If the gardener applies frequent but shallow irrigations much of the water will be lost by evaporation. Applying deeper but less frequent irrigations is more efficient but can easily lead to loss of water past the root zone, and valuable nutrients.
The wicking is a solution to this problem. In its simplest form a water reservoir catches any excess water from above ground irrigation and feeds it back to the plants as they use the water.
With a wicking Earthbarrel water is fed directly to a water reservoir so all the plants water needs are supplied from the reservoir by wicking action. This water is free to wick up to the layer of soil containing the root zone.
Depth of wicking soil
The depth of the water reservoir should not be greater than the height which water will wick upwards, generally this is less than 12 inches. If the reservoir is deeper than the wicking height there will be a stagnant pool of water remaining which cannot feed the root zone. This will impair scheduling based on reservoir depth. Reservoir depths of 8 inches work well and are commonly used. In a wicking Earthbarrel the depth of the soil above the water reservoir should be adequate to accommodate the root system of the plant. Again the normal range is 8 -12 inches.
Wicking Earthbarrels are very easy to schedule watering. Watering is needed when the water reservoir is empty. Water may be applied directly to the reservoir by the distribution tube. A overflow pipe indicates when the reservoir is full. It is not so critical when to water. Even if the reservoir is empty there will still be water in the soil above, so the plants will not suffer if the watering is a little late. If there is a little water left in the reservoir it is not important as it will simply take less water to fill.
The possibilities are unlimited!