Yuzu: Citrus Fruit For Harvest in Winter

A citrus fruit that can be grown in temperate climates and harvested in Winter for holiday recipes.

Yuzu is a citrus fruit that is very popular in Japan.  The fruit looks similar to a tangerine, but is more yellow and the skin is bumpy.   Similar in flavor to a lemon but more delicate, Yuzu was introduced into Japan from China during the Nara period (710-794 AD) and is now a staple in Japanese cooking; Japanese food lovers and cooks will be most familiar with Yuzu as it is the primary ingredient in Ponzu sauce.

Tolerant to 10 Degrees Fahrenheit

Yuzu is unique among citrus fruits because of its extreme cold tolerance.  Unlike other citrus fruits, Yuzu can tolerate cold temperatures as low as ten degrees Fahrenheit.  This means that gardeners in temperate climates (USDA Hardiness Zone 5 and higher) can successfully grow it their garden if they would like to do so.  Yuzu can also be purchased as a dwarf tree and grown in a pot indoors by anyone.  In the garden or inside, Yuzu can be enjoyed year-round:

• Beautiful green foliage 12 months of the year.
• Fragrant flowers in May or June.
• Ripe fruit in December or January.

Growing Yuzu

Depending on where you live, you may be able to purchase Yuzu from your local nursery.  If not, Yuzu can be ordered from FourWinds Citrus Growers and several other suppliers.  One thing to note when searching, the current taxonomic name for this citrus is Citrus ichangensis x C. reticulata but the plant is often sold under it's old taxonomic name Citrus junos.  

As with other citrus, you should grow Yuzu in well drained soil.  In my area, the soil is a miserable clay, so I grow my Yuzu in a SmartPot (a fabric growing bag) that provides great drainage and air circulation to the roots.  Here are basic care instructions:

• Plant in well drained soil.
• Keep soil moist but don't allow the roots to get waterlogged.  The best approach is to provide one deep watering per week (versus many shallow waterings).
• Fertilize with a nitrogen weighted fertilizer -- more "N" in the formula than Phosphorus (P) or Potassium (K).  Apply fertilizer are rates per the manufacturers recommendation.
• Plant or place pot in full sun.  If you use a pot, you can move your tree indoors or to a greenhouse during the Winter to provide additional protection.  This is the only option for gardeners who live in Hardiness Zones 1-4 and is probably also a good option for those living in Zone 5 (the lowest zone where Yuzu can be successfully grown outdoors)

 Yuzu Recipes

If you decide to grow Yuzu, here are some potential uses:

• Candied Yuzu Peel - prepare the same way you would make candied orange peel, but substitute Yuzu.  Since Yuzu is harvested in December/January, this might make a nice treat for the holidays.
• Yuzu Marmalade - just substitute yuzu for orange in Alton Brown's recipe.
• Yuzu Liquor - this is traditionally made by steeping the peel in liquor and then adding back juice at a later point.  The traditional recipe for "Yuzushu" uses 35% alcohol Shochu (Japanese rice liquor) and requires that the liquor be aged for one year.  I have not tried this method of method yet, but I think a faster way to make Yuzu flavored liquor would be to substitute yuzu for lemons in the recipe for Limoncello (made with vodka rather than shochu).  See my prior posting on how to make limoncello for details. 
• Ponzu - A traditional Japanese dipping sauce.

Comments

[Paul d'Aoust]

Thanks for the information; I just bought a yuzu tree myself and I was looking for a few bits of info on how to keep it happy. Nice to know it doesn't flower until May or June; I was informed that mine would flower this year and have been disappointed so far, but May ain't over yet!

One thing I wanted to point out: 10°F is more like USDA zone 7 or 8, and also other people have discovered that the yuzu can only survive transient drops to 10°F -- only a few days at the most. More prolonged drops killed their trees. I'm in zone 6 (0 to -10°F) and I wouldn't dare plant mine permanently outside, let alone in zone 5 (-10 to -20°F).

The Japanese bitter orange, however (Poncirus trifoliata, aka Citrus trifoliata) can survive down to zone 6 or even 5, and is often used as the rooting stock for yuzu. However, it only lends a few more degrees of cold tolerance to the yuzu itself.