Wednesday, July 11, 2012

One of my favorite Citrus trees.....

I was working a Master Gardener event this past weekend at Magnolia Gardens. I love being out there.
While a few of us were sitting in the booth waiting for clients, the discussion of Citrus came up. This is NOT unusual when I am around, see the name of this blog if you are wondering why.
Carolyn was telling me about her trees and how well the one that I gave her a couple of years ago was doing. She actually won it by answering a question at one of my lectures. Anyway, she was telling me that one of our mutual friends and fellow Master Gardeners, Ted, has been trying to talk her into buying and planting a Kumquat.
I COMPLETELY agreed with him.
Kumquats are a group of small fruit-bearing trees in the flowering plant family Rutaceae, and are in the the genus Fortunella. They are known as "The little gold gem of the citrus family".


The plant is native to South Asia and the Asia-Pacific region. The earliest historical reference to Kumquats appear in literature of China around 1178 A.D. They have long been cultivated in Japan, Taiwan, the Philippines, and Southeast Asia. They were introduced to Europe in 1846 by Robert Fortune, collector for the London Horticultural Society, and shortly thereafter into North America. Today they are grown mainly in California, Florida and Texas on a commercial basis, but show up in backyards as homeowners discover the many uses of this tangy little fruit.
The Kumquat is slow-growing, shrubby, and compact, attaining heights of 8 to 15 feet tall. Like the majority of its other relatives, it is evergreen.
They prefer full sun, which translates to 8-10 hours. Moist soil, not wet. I like to use the analogy of the soil moisture needing to be the consistency of a wrung out dish sponge.
Kumquats, again like all Citrus, are heavy Nitrogen feeders. I use an organic product put out by Espoma called Citrus-Tone. For in ground trees in my Zone 8, I apply about every six weeks starting around Valentine's Day and stopping about Labor Day. This gives the new growth time to harden off before the cold weather hits. If you are growing them in containers, I will have more on this in a minute, you can feed year round, especially if they are going to be protected or are in no danger of cold weather. If you can not find Citrus-Tone, Holly-Tone is an acceptable substitution. If you can't find that either, any of the water soluable fertilizers for Acid Loving plants are good too. I mentioned they are heavy Nitrogen feeders, if you want to give your tree an extra treat, spray Fish Emulsion as a foliar feeding every couple of weeks. Remember that this does have a fairly bad odor and if you are bringing your plant inside, you may want to skip this step or stop using it WELL before bringing it in.


It has been reported that the Kumquat can withstand temperatures of 10 to 15 degrees and frost without injury. It grows in the tea regions of China where the climate is too cold for other citrus fruits, even the Satsuma orange. I know I have seen them handle 18 degrees here in Charleston, SC without even blinking an eye.
This is completely a mute point if you can grow them in a container. Being that they attain heights of only 8-15 feet, they are very well adapted to being grown in a pot.
There are few things that you need to remember however. They still need the same amount of sunlight. With that many hours of sun, you will need to water much more frequently because the rootzone in a black container can easily reach 120 degrees, and that will dry it out much faster.
Any good potting mix will work. There are some labeled for Cactus and Citrus, I know, odd combination, but it does work. If I happen to be using one of the store bought soils I like to add a little bit more sand, more for weight and volume than any other purpose.
In container culture, you also need to be very aware of your plants fertilizer needs. I mentioned the Nitrogen. The Kumquat needs this is large amounts. I bet you can guess which nutrient leaches out of the soil the fastest? If you guessed Nitrogen, you would be correct! That is why I suggest feeding every 6 weeks or so.
Don't believe me that they can grow in a container? Check this out:

As you would imagine, there are different species of Kumquats and not really different cultivars.
The most common one is the 'Nagami', or Oval Kumquat (Fortunella margarita). I had a few pictures of these back towards the top of this article. This is the most often cultivated Kumquat in the United States and the one you usually see in the grocery store around Christmas. They are up to 1 and 3/4 inches long and 1 and 3/16 inches wide; the pulp is divided into 4 or 5 segments, containing 2 to 5 seeds. It is in season from October to January. A mature specimen at Oneco, Florida, in 1901, bore a crop of somewhere between 3,000 to 3,500 fruits.
The next most common one is the 'Meiwa', or Large Round Kumquat (Fortunella crassifolia). These are about 1 and 1/2 inches wide; the peel is orange-yellow and very thick. The sweet pulp is usually in 7 segments and are often seedless or with few seeds. This kumquat is the best for eating fresh.


The 'Marumi', or Round Kumquat (Fortunella japonica) is much less seen. The fruit is about 1 and 1/2 inches wide. The peel is golden-yellow, smooth, with large oil glands. It is very aromatic and has a spicy pulp with 4 to 7 segments.


When it comes to pests, in ground and container plants pretty much have the same pressures. Mealybugs, Aphids, Grasshoppers and Orange Dogs, just to name a few. Most of these can be handled with Insecticidal Soap or a light horticultural oil. The Orange Dogs can also have Bt used on them, they are caterpillars and if you have never seen one, take a look at this:

Yes, that really is a bug and not a bird that was taking aim.
Compared to other fruits like, Apples, Pears, Peaches, etc, Citrus are comparatively free of disease, but they have some doozies! I will not get into them here, you can check out my articles on one of the Citrus Diseases HERE and the Citrus Quaratines HERE .
Propagation of Kumquats can easily be done by planting the seeds from fresh fruit you obtain at the store. You will read some reports that they do not do well on their own roots, mine seem to do just fine and I have talked to others that say the same thing. I believe it is just how well you treat the tree as to how well it will grow.
First you will want to get the seed out of the fruit. If you are cutting the fruit, be careful not to cut the seed. Clean the seeds. Simple water and hand rubbing is all you will need. Kumquat seeds are polyembryonic, which means they have more than one embryo inside the seed. At least one of these will be identical to the mother tree! DO NOT DRY THE SEEDS! Sorry to yell, but drying out the seed can kill the seed embryo. Use moist potting soil in a small planting pot. Plant the seed about half again as long as the seed. Keep the pot covered in a warm spot. In 3-4 weeks they should germinate. After that you need to slowly get it use to more and more sunlight until it is getting the 8-10 hours. Within about 5-7 years you should start to get fruit, depending of course on how well you care for the tree.
You can also graft, but that is a topic for a whole other article.
While the most common use for the Kumquat fruit is to eat it whole, as is, peel and all, other popular uses for the fruit include adding pieces of it to fruit salads or to dessert recipes. Kumquats are also used to make jellies, jams and marmalades. I should mention here that I despise Marmalade, however, Kumquat Marmalade is amazing. Kumquats are also often pickled whole or preserved in syrups for future use. In recent years Kumquats have gained popularity as a garnish for cocktail beverages, including the martini, as a replacement for the more familiar olive. You might also even be able to purchase candied Kumquats at some ethnic grocery stores.
So as you can see, the Kumquat can be a very handy, decorative tree. It is easy to grow, produces a bountiful harvest and there are all kinds of things that can be done with the fruit. Why not make your next plant purchase a Kumquat tree?
If you are growing other Citrus, you could even possibly make a new hybrid. I only include this list as a parting shot because I get asked if they are at all related. Yes, these are TRUE plants out there and this will tell you who or what their parents were:

Limequat - key lime + kumquat
Orangequat - Satsuma mandarin + kumquat
Calamondin - tangerine + kumquat
Citrangequat - citrange + kumquat
Mandarinquat - mandarin + kumquat
Procimequat - limequat + kumquat
Sunquat - lemon + kumquat
Yuzuquat - yuzu + kumquat

Happy Growing!