Sub-Irrigation Planters (SIPS) for Figs
By Steven Biggs
Reservoirs Keep Fig Plants Well Watered
Avoid water stress and fruit drop of figs using an SIP
When the soil of your potted fig gets too dry…it might drop fruit.
There are a few things you can do to give your potted fig plant enough water and prevent fruit drop, you can:
Water it regularly
Sink the pot into the soil, even just a couple of inches, so that the plant can sends roots into the surrounding soil to get additional water
Use a container that stores water, such as a sub-irrigation planter (a.k.a SIP)
Sub-Irrigation Planter (SIP)
A sub-irrigation planter (SIP) made from a storage tote, 4" weeping tile, and a dishwasher drain pipe. What you don't see in this photo is the drainage hole at the same level as the top of the weeping tile.
A sub-irrigation planter (SIP) made from a storage tote, 4" weeping tile, and a dishwasher drain pipe. What you don't see in this photo is the drainage hole at the same level as the top of the weeping tile.
Sub-irrigation is a fancy way of saying that you’re creating a reservoir at the bottom of the container. Water wicks upwards into the soil — either through the soil iteself or through a wicking material of some sort.
There is a fill tube that extends upwards so that you can fill up the reservoir from the top. The soil mix acts like a wick and the water moves upwards. You just need some soil that dips down into the edge of the reservoir.
The Planter
If the planter has no holes, drill an overflow hole in the side, at the height of the top of the reservoir. This overflow hole prevents your soil from getting waterlogged if you overwater or if there is a lot of rain.
You can install this sort of system into a container with holes by using a waterproof liner at the bottom.
Liner
I’ve often used contractor-grade plastic bags or vapour barrier. Use anything that will hold water within the pot.
Reservoir
Making a sub-irrigation pot using a black nursery pot lined with a thick plastic bag. The reservoir is created from flower pots. Over the top of this i put wire mesh and landscape fabric to hold up the soil.
Making a sub-irrigation pot using a black nursery pot lined with a thick plastic bag. The reservoir is created from flower pots. Over the top of this i put wire mesh and landscape fabric to hold up the soil.
The reservoir is the soil-free space at the bottom of the pot where you store water. You need something to hold up your soil mix. You can use weeping tile, inverted flower pots, old juice jugs…just go through the recycle bin and use your imagination.
Fill Tube
I find the plastic tubing used for draining dishwashers (look in the plumbing section at the hardware store) is a nice diameter for filling with a hose. You can also use old downspouts, plastic bottles…again, use your imagination.
Fabric Cover
I like to put some burlap or landscape fabric over the top of the reservoir area to prevent soil from migrating into the reservoir too quickly.
Not Just Figs
I also use sub-irrigation planters on my garage roof to grow vegetables. The planters drastically reduce the frequency of watering, and the plants grow better because they don’t have water stress.
The fill tube for filling the reservoir below