SIP : Sub-Irrigated Planters

Also known as "Self Irrigating", "Self Watering" or even "Automatic Watering" planters, these containers are your best bet to optimise water usage. They are neither new nor rocket science..
Hanging Gardens of Babylon

SIPs aren’t new. In fact, they are ancient. The technology is supposedly used to create the amazing “Hanging Gardens Of Babylon” dated 605BCE1 . The plants were all above ground and grown in containers. It is claimed that in order to keep the vegetation lush in the hot dry dessert environment, they must have used some form of sub-irrigation technology. Then again, proponents of Hydroponics claim that they actually use only water, nutrients and growing medium2 . Of course, the very existence of this ancient “city in a garden” is still part of a raging debate 3.

The first modern day implementation of SIP was by Professor W.J. Green (how appropriate!) in Ohio in 1890. He made use of “concrete and clay tiles to create the planter using a greenhouse bed” 4.

But this is predated almost 2,500 years ago by the gardens at the Rahmat Rahel site. These gardens relied on an advanced irrigation system that collected rain water and distributed it to underground channels, tunnels and gutters 5.

“Why then is our consumer horticultural education system still fixated on drain holes, sprinklers and other overhead irrigation systems that waste water when compared to sub-irrigation?

Add the fact that sub-irrigation increases yields and produces healthier plants and we have a mystery of the modern age of climate change, conservation and sustainability.” 5

SIPs mimic nature and comprise of the following:

  1. Water reservoir at the bottom, just above which is a separator which prevents the soil from mixing with the water. Typically, this reservoir is 1/4 the volume of the entire pot.
  2. Water Inlet Pipe where you feed the water directly into the water reservoir.
  3. Most commercial implementations include a Water Level Indicator so that you fill in only the amount of water required.

SIPs are now catching on and are available commercially in all kinds of sizes, shapes and colour. They all have similar components as described above. The price ranges from $5 to $500 depending on the size and design. It makes economic sense to get the more affordable versions (MIC) and upscale them yourself e.g. they may not contain the inlet pipe, you can easily add a recycled PVC or metal pipe.

You can also DIY them yourself using 1.5 Litres PET Bottles or larger 5 Litres Rectangular PET Bottles. The concept of making one yourself is the same. The limitation is your imagination and creativity!