Turn up the Heat

Use thermal mass to increase the amount of heat your figs get.

Use thermal mass to increase the amount of heat your figs get.

Around here, we’re only a couple of months away from that first fall frost that puts an end to any hope of ripening more figs.For someone like me, with no background in energy, the comment sounded profound; yet so simple.

The alternative energy expert (whom I interviewed about home energy generation) told me not to forget “thermal mass,” which, he felt, is as important as generating energy. In his projects, he combined solar and geothermal technologies with the idea of thermal mass.

What he meant by thermal mass was using building materials that capture and then slowly release heat, materials such as tile and concrete. It was very logical, of course, but I’d never thought about it before.

We’re in the middle of a heat wave here in the Toronto area. Yet already, the nights are becoming cooler. As temperature swings between day and night become greater, using thermal mass in the garden is a technical-sounding, yet simple way to given fig plants more heat. Remember: More heat for our fig plants means more ripe figs before the fall frost arrives!

If you already have your fig near a paved driveway or brick wall, then it’s benefitting from thermal mass. At night, the driveway or brick slowly radiates heat that has been stored during the day, keeping the air temperature around your figs a bit warmer.

I was reminded of this a couple of weeks ago when I visited my friend Andrea, who recently planted a fig hedge (which she intends to overwinter with an insulated A-frame). As I stepped—barefoot—onto her patio, the dark stone singed my feet. It was scorching hot. When it rained a short while later, the stone dried within minutes because it was so darn hot!

Andrea’s figs have a really great “micro-climate.” They’re surrounded by that heat-capturing and heat-radiating stone. At night, those figs bathe in radiated heat. All thanks to thermal mass.

Fig Hedge

My fig hedge is looking nice, with the neighbouring peonies adding splashes of pink.

Over the winter, I lay the potted figs in the trench and cover with mulch. The trench becomes my fig hedge over the summer. In the spring, I put the potted figs in an upright position in the trench, and then mulch so that the ugly black pots are out of sight.

Biggs with 5 Tips on Figs

Watch this video for 5 tips on growing fig trees in cold climates.

This video is not new, but I share it again so that northern gardeners can fit figs into their 2016 garden plans.

Thanks to my friend Susan Poizner of Orchard People for making this!

Learn to grow fig trees even if you live in a cold climate! Steve Biggs, author of "Grow Figs Where You Think You Can't" gives his top five tips for growing fig trees. For more information or to order a copy, visit www.http://www.grow-figs.com/. Film produced by Orchard People Fruit Tree Education at www.orchardpeople.com

It’s cold out, so let’s talk figs!

Grow figs in cold climates.In December I had the pleasure of talking with the host of the Urban Forestry Radio Show, Susan Poizner, about growing figs in cold climates.

Click here to listen to me talk about growing figs on the Urban Forest Radio Show.

A long-time journalist and a gifted storyteller, Susan shares my passion for growing edibles.

Susan, is the founder of Orchard People. She offers workshops and online training about growing fruit trees. And she is the author of the award-winning book Growing Urban Orchards: The Ups, Downs and How-Tos of Fruit Tree Care in the City. Visit her website for a great newsletter and free e-book.

Last Fall Figs

Pictured  is my fig-growing friend Joe. The frost has burned the leaves on his fig plants and he's picking the last figs of the season.

Mice and voles can be a challenge when overwintering in-ground figs are covered with mulch or are snug and warm in a tunnel. They love to eat the bark, which girdles the tree.

When I visited Joe one spring, a few of his plants had been girdled...

Not last winter! Joe told me that a family of weasels nested around his fig plants--and they took care of rodents.

Fig hedge fall update

In an earlier blog post, I showed the first stages of my cold-climate fig hedge. Here’s how it looked at the end of summer.

Consider a fig hedge if:

  • you want a privacy screen that is both attractive (beautiful lobed leaves) and delicious
  • like me, you have too many fig plants to otherwise fit into your garden!

Fig Breba Crop

Fig breba cropThe early fig crop (which, here in Toronto, starts to ripen in July) forms on wood from the previous year. It is called the "breba" crop.  ("Main" crop figs form on wood from the current year, in late summer.)

Some fig varieties produce both breba and main-crop figs, but not all of them give both crops. And...some varieties give an especially heavy breba crop.

If you're like me and don't like to wait until late summer to start gobbling up figs, get a fig plant that gives a heavy breba crop, like the plant in the accompanying photo. 

(Fig growers in the pacific northwest often grow varieties with good breba production because they don't always have enough summer heat to ripen a lot of main-crop figs.)

Of course...I also want varieties with a good main-crop production, which it how I justify having multiple fig plants!

 

  

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.

Dormant Potted Figs

Dormant fig trees. Don't overwater!A lot of people ask me how often to water domant potted fig trees during the winter. Here is what I say in my book Grow Figs Where You Think You Can't:

Watering Dormant Fig Plants

Dormant figs are more likely to die from overwatering than from underwatering.

While plants are dormant, it’s important to strike the right balance in watering: enough that the dormant trees don’t dry out and die, yet not too much that the roots rot. I usually check them about once a month.

If you’re not sure whether your plant should be watered, stick your finger in the soil and feel around, digging down a couple of inches to feel if it’s moist.

In winter, you want to keep your plant dormant, which requires cool, dark conditions.

COOL + DARK = DORMANT

Making a Heat Column for In-Ground Fig Plants

I have been in touch with a Pennsylvania fig enthusiast named Will. He told me that the harsh winter of 2013/2014 took a heavy toll on fig trees in his area. Trees without very good protection were killed right back to the ground.

Will grows upright, in-ground fig plants. His protected tree did NOT die.

He sent me the pictures below of his clever system of protecting in-ground fig trees.  

Overwintering fig trees in cold climates, with a bit of creativity, is possible. Thanks, Will, for sharing! 

 

Will says: “The system incorporates a 40-watt incandescent light bulb suspended in a 4-ft. tin exhaust tube (3-inch diameter). The light is turned on only when the temperature goes below 15°F (-9°C) and turned off when the temperature gets above 15°F (-9°C).”

 

 

 

 

 Will says: “I have protected the tree under an inverted tomato cage.”    Will says:“The 40-watt bulb is tied to the tree which is tied and wrapped in burlap. The tube acts as a heat column beside the tree. Then, both are placed inside the inverted tomato cage and wrapped in a Planket (which is waterproof but breathable).”

Will says: “The heat tube must be turned off when nighttime temps rise above 15°F (-9°C). I use both 25-Watt and 40-Watt bulbs depending on the size of the tree.

Main-crop figs in the Pacific Northwest

Bob Duncan grows figs near Victoria, BC, CanadaLast month I had the pleasure of visiting Fruit Trees and More, a nursery near Victoria, BC, Canada run by Bob and Verna Duncan. (I went out with an empty suitcase so that I could come home with a medlar, kaffir lime, and a new variety of olive!)

Bob explained that while they have mild winters, summers are not hot. That means that ripening main-crop figs (figs that form on wood from the current season) can be challenging. Most fig growers in the Pacific Northwest, he explains, focus on varieties the form breba figs (the early crop that forms on wood from the previous season.)

So how does one ripen main-crop figs in the Pacific Northwest? Bob has built greenhouse-like structures with open sides. The higher temperature within these structures, he believes, will give better results ripening main-crop figs.

 Bob Duncan's open-sided fig house in the Pacific Northwest

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!

Pictured to the right is my fig-growing friend Joe on a balmy October day (balmy in the plastic tunnel, that is!) inspecting his figs. (see Joe's website for figs, Prickly Pear Cactus, Grapes, Blackberries and other edible plants)

Pictured below is Joe with those same plants during the summer, when there is no plastic over the metal frame.

Figs growing in the ground, with metal frame to support plastic film for late fall and winter.

Fig Pig Patio Garden at TBG

Paul Zammit planting a fig plant in the new TBG Fig Pig Patio gardenCheck out the new Fig Pig Patio garden at Toronto Botanical Garden (TBG)!

TBG director of horticulture Paul Zammit says this garden was replicated from my plan in Niki Jabbour's new book, Groundbreaking Food Gardens.

In this plan, I combine figs, cardoons, and colourful Swiss chard. I grow the figs in a tree form, to allow space below for the cardoon and chard. For the TBG, Zammit says that he will grow the figs in a fan shape in the centre of this fairly narrow bed. It should be stunning. I'm stoked!

Fig Pig Patio plan from Niki Jabbour's new book, Groundbreaking Food Gardens

 

 

Biggs on Figs at Toronto Botanical Garden

Yes, you can grow figs in Toronto! Join Biggs to learn about growing figs: Toronto Botanical Garden, June 12.

Get the simple truth about growing a crop of figs at home. And get first-hand tips on propagating your own fig trees.

MOST IMPORTANTLY... see how other gardeners in Southern Ontario overwinter fig plants. Overwintering figs takes a bit of creativity...and this class will get your creative juices flowing!