Growing Kumquats

 Today I’ll be talking about the sweet and sour goodness that is the Kumquat fruit!

 Kumquats are a uniquely delicious fruit. They look like thumb-sized oblong oranges because…well…that’s what they are!  Originally from China, they’re now grown all over the world in tropical and subtropical climates. They’re pretty fun eaten fresh as you simply pop the whole thing in your mouth- skin and all. It takes awhile to convince kumquat newbies that they don’t have to peel the skin. In fact, some people just eat the skin and throw the pulp away (the skin is actually the sweetest part of the kumquat-Weird!). I happen to like the contrasting sweet and sour flavors, so I don’t do that.  It’s a great taste experience.

 Kumquats are often candied, something I haven’t tried to do yet, but will soon since I have so freakin’ many of them.

   The two main types grown in the US are Nagami and Meiwa. I don’t know the difference other than the shape: Meiwa is rounder than Nagami.

    One of the  crazy-cool things about Kumquats is that the fruit ripens (depending on variety) in mid winter to early spring. Fresh fruit in Feburary? Awesome!

 Cold Hardiness

  Kumquats happen to be among the most cold-hardy citrus trees on the planet, and probably the only cold-hardy citrus that is more than barely edible. There are many species of citrus that can take the cold, such as the trifoliate orange, but most are blatantly inedible. I mean, would you like to eat something called a ‘trifoliate orange’? Give me a break.

 Kumquats can take temperatures down to 10 degrees Fahrenheit when they are dormant. At least, that is what I’ve been told. Since planting the tree four years ago we have not experienced temperatures that low, and I hope we never do. When they are dormant is the key term here. You won’t be protected against any early or late freeze, and sometimes, during a winter warm spell in the South, the trees will ‘wake up’ before they’re supposed to, only to take serious damage during the next round of cold weather.

  Kumquats, like all citrus, are risky even in the deeper parts of the Southern US. Cold weather happens, and unless global warming decides to kick into full gear soon, you risk losing your lovingly tended tree that you’ve watched grow up for all these years. While they can be protected (more on that later), sometimes there’s only so much you can do. I wouldn’t try it below zone 8 outdoors. But, as they say, nothing ventured nothing gained, and a Kumquat tree only costs 15-20 bucks so you really have nothing to loose and lots of small, oblong, sweetly sour fruits to gain.

  For many of you, if not most, citrus killing temperatures are a frequent occurrence. For such folks, growing kumquats in a container is a viable option; letting them live outside on your patio during the summer and bringing them in for the winter. However, you will likely have to find a kumquat on a dwarf rootstock for this, as a full sized tree would quickly become rootbound.

Growing

 Kumquats grow well in most soils, though a sandy loam is ideal. They, like all citrus, appreciate a few doses of nitrogen each year, most easily applied through foliar spray with Fish Emulsion. I personally let my chickens in the citrus orchard once a year. Their nitrogen-rich manure does the job nicely.

  Pruning isn’t necessary, as the tree will take a nice shape on it’s own. Your main concern, once again, will be keeping it warm. There is nothing more unpleasant that being out a 8:00 in the evening on a cold winter’s night spreading drop cloths over your kumquat tree, but it’s a worthwhile sacrifice. I protect mine whenever the temperature drops to 24 degrees or below, although you could probably let it get a little colder before worrying about protection. I like to be on the safe side. Here’s some ideas for covering-

• “Banking Up” the soil around the trunk- This is good to do anyway when winter starts. Simply  mound up soil 6 inches high or so around the trunk, then put mulch on top of that as an added precaution. Remove the dirt mound in the spring.

• Blankets, dropcloths, quilts, etc. When it’s cold at night, what do you do? Why, you snuggle under the blankets, of course! Kumquats appreciate this tactic equally. If it’s a windy night, be sure to tie the blankets on the branches or use string. If you’re blankets fall off at night you can pick it up and wrap it around yourself again, Kumquats don’t have this luxury. The heaviest blankets are the best. Don’t use plastic sheeting like Visqueen as it could actually exacerbate the problem.

• For extra cold weather, try wrapping Christmas lights around the tree before spreading the blankets. You neighbors may think you strange for stringing Christmas lights in February, but there’s nothing you can do about this.

• For really cold weather, some people place an electric or propane heater near the tree, under the blankets. This is probably the most unsustainable thing you could possibly do, as well as a significant fire hazard. I personally would just let the darn thing die, but in theory it should work well. Your neighbors at this point might start making phone calls about you.

•  Overhead irrigation is used often in large commercial citrus farms. You could simply run a sprinkler at night, making sure most of the branches are hit. This method will not be effective at very cold temperatures. This might not make immediate sense, but the following explaination is helpful-

    The latent heat of water, released when the water freezes, is the principal factor involved in protecting the plant. One gallon of water at 320 F, changing into ice at 320 F, gives off approximately 1200 BTU’s (British Thermal Units) of heat. Some of the heat released goes into the plant leaves and blossoms, some goes out into the air and some goes to the soil. The heat absorbed by the plant is enough to keep the plant above its freezing point, except when the air temperature is very low or when heat is removed rapidly by a cold wind. There is some transfer of heat because the water temperature is above freezing, but most of the protection comes as the water freezes and latent heat is released. The slush ice and the increased humidity also increase protection. -source    

 

• Flying a helicopter continuously over your tree at night will also help, as the rotors will push warm air downwards. Laugh if you will, but I know of a fellow blueberry farmer who has done this. You neighbors might not appreciate this tactic either.