Sub-Irrigated 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-Irrigated Planter (SIP)

A sub-irrigated 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-irrigated 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

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Intro to How Figs Grow

By Steven Biggs

Figs Tolerate New Gardeners

Leaves are deciduous, which means they fall off when cold weather arrives.

In the book Grow Figs Where You Think You Can't, I repeat a simple message for readers: In places where figs don't usually grow, they are easy to grow.

One of the reasons for this is that that they're such resilient plants.

Here's what I say in the book:

Forgiving Plants

The first thing to remember about figs is that they are very, very forgiving plants. Remember that fig cutting I told you I took as a teenager? It languished under barely survivable conditions for 15 years until I gave it a proper spot.

They Want to go Dormant

The next most important thing about the way figs grow is that they lose their leaves after first frost. They WANT to go dormant. That means you can keep them over the winter even if you don’t have a bright, hot greenhouse. While they’re dormant, they don’t need light or much heat. Contrast this to lemons…

The large, lobed leaves grow on branches with grey bark. When cut, branches exude a milky white sap that can be irritating to the skin. Leaves are deciduous, which means they fall off when cold weather arrives. Unpruned, plants usually grow into a bush, but can be trained into small trees if that’s what you prefer.

Grow Figs, Even in Cold Climates

How to Grow Figs…Even in Cold Climates

Fine Gardening – Issue 201

By Steven Biggs

Read more about growing figs in cold climates in my article in Issue 201 of Fine Gardening magazine.

Step-Over Figs

I order straw bales for my kids to play with—they're like giant biodegradable Lego blocks. They all become mulch eventually!

By Steven Biggs

Straw for Kids and Figs

I USE LOTS OF STRAW in the garden. Last spring we got 30 bales. When I say we, I mean the kids and me. For the first while, the bales are all for play: giant biodegradable building blocks!

Over the summer, some of the bales break as the twine comes off. I use the loose straw for mulching.

Step-Over Figs

In October, I lay full bales over top of fig plants that I'm growing as "step-over" figs. These plants have low, horizontal main stems. 

I cut all of the branches from the main stem in the fall, making it easy to lay straw bales over the top.

With the step-over system, I select varieties that produce a good crop of "main crop" figs. These are the figs that grow on branches from the current season. New shoots can produce figs in one season.

The Challenge in my Garden

A step-over fig with a low, horizontal trunk that is easy to mulch and protect for winter.

Under the straw bales: Step-Over figs that are tucked in for the winter.

So far so good, right? Sort of. The concept is sound—and the straw does a great job of protecting my fig plants.

But...this corner of my garden is low and the soil is slow to warm up in the spring. The result is that my step-over fig plants don't start growing early enough to ripen many figs.

Lesson learned. I've started step-over fig plants in a warmer spot close to my patio.

And the solution for the step-over figs in these photos? Growing figs in cold climates often requires some sort of season-extending technique... And I think that the solution for me might be to install a low hoop-house over top of these figs in the spring. It will warm up the soil and get the plants out of dormancy sooner.

Fig Hedge

A fig hedge for a cold climate!

The potted fig plants are in a trench. With the addition of a layer of mulch, the ugly pots are out of sight.

Figs are beautiful plants, with large, lobed leaves and smooth, grey bark.

The fig hedge will be beautiful. (And delicious!)

In November, once the trees are dormant, I will lay them over and cover them with mulch to protect them from extreme winter temperatures. (Any that don't fit in the trench for the winter will go into my garage.) 

Hiding Pots with Potted Figs

Trench for potted figs. Once backfilled with mulch, the pots and the boards lining the trench will not show.I sink my potted fig plants part way into the ground so that they can root into the surrounding soil. This prevents plants from tipping over in the wind, and allows them to scavenge food and nutrients from the soil.

Equally importantly, sinking the pots helps to hide them!

But digging holes for the pots every year is a lot of work. And...I want the pots completely out of sight. 

So this year, I've made a permanent trench. After I put the potted fig plants into the trench, I'll simply backfill with wood chips or bark. 

Advantages:

• Pots are below grade and completely hidden under mulch

• Pots will stay cooler and dry out more slowly

• In autumn, wood chips are easy to remove when it's time to remove the trees for indoor storage

Stay tuned...I'll report back on how well this works this autumn.

Extending Fall Fig Harvest

Extend fall fig harvest with a plastic tunnel or greenhosueFIG GROWERS IN TEMPERATE CLIMATES know that lots of the figs on their plants won’t ripen before the first fall frost causes the plant to go dormant. Such a waste!!

Some fig lovers protect fig plants from fall frost to allow more fruit to ripen before the tree goes into dormancy.

An unheated plastic greenhouse or tunnel can raise the air temperature considerably—delaying dormancy, and ripening more figs. Yum!

Video: How to Grow Figs

If you think it's too cold to grow figs where you live, watch this video.

Maybe you can grow figs, even if they are not winter hardy in your area.

Fig trees are very forgiving plants that will take a lot of abuse.

In this video, I explain how to grow figs in places where they wouldn't normally survive the winter. It's not difficult! And you don't need a greenhouse to do it.

This is a talk I gave at Richter’s Herbs in 2013 about how to grow figs in cold climates.

As Steven Biggs puts it, "Growing figs shouldn't seem exotic; it should be straight forward stuff!" Indeed, a growing coterie of gardeners across Canada and ...

A-Frame for Winter Fig Protection

Last week, my boys and I stopped by Adriano's for a visit.

Adriano grows it as a multi-stemmed bush, cutting out stems that become too big and, therefore, less flexible.

His potted trees were outside; still dormant, but buds swelling nicely.

He showed me his in-ground Desert King fig that overwinters covered with an A-frame.

Alternative to Burying Your Fig

Thinking of growing an in-ground fig, but don't want to chop the roots and lay it flat?

The A-Frame method is another approach to overwintering figs if you're in zone that's too cold for figs to survive unprotected.

Uncovered for Spring

He says this big in-ground Desert King fig has been there for about 40 years.

He grows it as a multi-stemmed bush, cutting out stems that become too big and, therefore, less flexible.

When winter comes, he bends over the branches, and then places an insulated A-frame (made from wood and styrofoam) over the top.

Through Summer

It never fully stands upright, but instead is bent over, so that it looks as if it is praying!

Figs in Garden Making Magazine

Get the latest issue of Garden Making magazine, which has my article about growing figs in cold climates. The magazine is on shelves now, or you can order online. Visit the Garden Making website.