A water-stressed fig tree does something that makes gardeners weep: It drops unripe fruit.
This year I'm growing more figs in large pots with sub-irrigation. It’s a great way to minimize water stress.
I like the sub-irrigation system for places where I can't sink potted figs into the ground for the summer. (When potted figs are sunken into the ground, even just a couple of inches, the fig plant sends roots into the surrounding soil for the summer.)
But my large pots with sub-irrigation are for my driveway...so no rooting out the bottom into the ground for these plants!
Sub-irrigation is a fancy way of saying that you’re creating a reservoir at the bottom of the pot. 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.
- If the pot 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.
I’ve often used contractor-grade plastic bags or vapour barrier. Use anything that will hold water within the pot.
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.
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.
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. Click here to read an article about my rooftop garden.