Yuzu - A Cold-hardy and Very Unique Citrus

I've found I enjoy raising fruit trees more than I enjoy vegetable gardening.  The maintenance requirements of fruit trees are typically much lower, there's very little weeding involved, and virtually all fruit trees look great in your yard.

North Carolina-grown Yuzu citrus

If folks in the Carolinas plant a fruit tree they typically choose a peach or apple tree.  I've got those too, but my love of all things tropical got me wondering just how exotic I could go right here in North Carolina.  A few Google searches back in 2007 led me to Stan McKenzie of McKenzie Farms in Scranton, South Carolina.  Stan is the "Johnny Appleseed" of citrus for the Southeastern U.S. outside of Florida.  Over the past couple of decades he has experimented with different varieties of citrus and has identified which ones can survive our winters.  He's also developed tried-and-true techniques of protecting citrus during hard freezes using microsprayers and water barrels -- both techniques utilizing the latent heat released from water as it freezes to protect the trees.

Confirmation that his citrus varieties and growing techniques work well came in the horrible winter of 2009-2010 when the temperature at his South Carolina farm dipped to 14 degrees F on three consecutive nights.  Cold of this magnitude would have utterly destroyed a citrus grove in Florida, but Stan's trees survived and even set fruit the following summer!

One of the trees Stan sold me is a unique variety called the Yuzu. (Citrus ichangensis x Citrus reticulata)  In English, it's a hybrid between the Ichang Papeda (a very cold-hardy citrus from China) and the Mandarin Orange.  Yuzus were first hybridized either purposely or accidently in China, but have achieved much more popularity in Japan and South Korea where culinary uses have been developed for its aromatic zest, juice and rind.  This is detailed in the Wikipedia article on Yuzu.

I moved my Yuzu from a pot to the ground in April of 2009 as an 18-inch tall tree.  The rootstock the Yuzu graft was attached to is Trifoliate Citrus. (Poncirus trifoliata, sometimes called Citrus trifoliata)  Why use a rootstock like Trifoliate Citrus?  Trifoliate Citrus does several good things for the tree:  it dwarfs the tree to a maximum height of 12 to 15 feet, it provides an additional few degrees of cold hardiness during the winter by forcing the tree to go into deep dormancy, and it protects against many kinds of root rot and soil-borne diseases that the Yuzu might be susceptible to if it were grown on its own roots.

My Yuzu really enjoys the North Carolina climate.  In less than four years it's grown to a height of nearly 10 feet and has produced an increasing number of fruits for my family each year.

     2008:  1 (while still in a pot!)
     2009:  0 (transplanted to the ground)
     2010:  2
     2011:  13
     2012:  42

My Yuzu tree just after transplanting in the ground, April 2009.

Yuzu, early spring of 2010

Yuzu, Summer 2011

My Yuzu tree now, September 2012

So what can you do with Yuzus?  They're too sour to eat like an orange, but the Japanese and Koreans are definitely onto something about the usefulness of the zest and juice.  Here's what my wife and I made with them last year:  Yuzu-Blueberry bread.

2 cups flour

1 cup sugar

1 tablespoon Yuzu zest

1 1/2 teaspoons baking powder

1 teaspoon salt

1/2 teaspoon baking soda

2 tablespoons canola oil

1/2 cup Yuzu juice

1/4 cup water

2 cups Blueberries (frozen are okay too)

1 egg

Icing:

1 cup confectioner's sugar

1-2 tablespoons Yuzu juice

Mix flour, sugar, salt, Yuzu zest, baking powder and baking soda together.  Add egg, Yuzu juice, water and oil, then combine.  Fold in the blueberries.

Pour into a greased bread pan and bake for 55-60 minutes at 350 degrees F, then cool on a rack.

Combine confectioner's sugar and Yuzu juice until smooth, drizzle over cooled bread.  

Harvesting the Yuzus.  In North Carolina the middle of October's a good time

Zesting the Yuzus.  If you've ever used Lemon or other Citrus zest you know now good this is.

Yuzu fruit cut open.  The seeds can either be discarded, or if you're ambitious, allowed to dry and then planted.  Don't store the seeds even slightly moist as they'll almost certainly be destroyed by mold.

Yuzu juice!  It's practically juice concentrate already with a powerful taste vaguely similar to a lemon/lime mix but not as "bright."  I don't have the culinary vocabulary to really describe it more than that.

Mixing  flour, sugar, baking powder, baking soda and salt with yuzu juice and zest.  Enlist the help of any nearby children.

  

Mixing in Blueberries last.  These were frozen since our Blueberries ripen in July and early August, well before the Yuzus.

  

Ready to go in the oven.

The finished and very yummy product: Yuzu-Blueberry bread!  These two flavors work really well together.

Since we're going to have so many more Yuzu fruit to experiment with this year I want to create Yuzu sorbet and perhaps Yuzu ice cream too.  There are some Korean hot tea ideas utilizing Yuzu and sugar that sound interesting as well.