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Nagami Kumquat: growing information

Nagami Kumquat

(Fortunella margarita)


Nagami Kumquat Overview:

If you like sweet and sour this nugget sized citrus fruit is for you.  This is a rather cold tolerant citrus tree that just gives and gives nearly all year long.

Nagami Kumquat fruit tree

Nagami Kumquat fruit


Nagami Kumquat Fruit:

Nagami Kumquat Fruit Appearance:

The fruit is the size and shape of a large olive.  However, the outer color and texture is similar to an orange.  The plant is very prolific and has fruit nearly the whole year.


Nagami Kumquat Taste:

This plant is unusual in the citrus family because the skin is edible.  In fact the skin is the sweet part of the fruit and is sometimes the only thing eaten.  The flesh is juicy but very sour and acidic, similar to the flavor of a lemon.  The fruit is ripe when the majority of the skin is orange with perhaps a small hint of green remaining at the top.


Nagami Kumquat Fruit Season:

I have read that the fruit matures late in winter.  However, I don’t think my Nagami Kumquat trees have read the books because there are fruits on this amazing tree all year.

Nagami Kumquat inside

Nagami Kumquat skin cut to show the inside of the fruit

Landscaping use:

  • The Nagami kumquat is a slow growing large shrub or small tree with an overall rounded shape and dense evergreen foliage.
  • Because the Nagami kumquat is among the most cold tolerant of all citrus, it could possibly be planted in lower parts of your yard that have a tendency to collect cool air.  However, the fruit is said to be sweeter when it is grown in warmer environments.
  • Nagami Kumquat has white fragrant flowers which and are similar in appearance to other citrus flowers.  Nagami Kumquat trees almost always bloom in the summer but I have noticed that the plant has a tendency to flower periodically throughout the year.  The small orange fruit make the plant very ornamental.  The plant is very prolific. In the main fruiting season (winter) there are so many fruit on the trees that I have that the branches completely bend over.
  • The Nagami Kumquat is also used in Bonsai and the plant is definitely suitable for large pots.
  • Prune in winter.
Nagami Kumquat

Nagami Kumquat branches bent from the weight of the fruit


Nagami Kumquat Tree Soil:

The Nagami Kumquat does better with slightly acidic soil.  Augmenting with lots of organic material will always help your citrus.

Click here to see my 6/9/13 post on the best planting technique to avoid transplantation shock.



  • Water on the same cycle as other citrus; 1 to 3x/week in the summer depending on your local micro-climate.
  • Infrequent deep heavy watering is much better than frequent light watering.
  • You can cut way back on the watering in the winter after the tree is established.
  • Mulching helps to keep the soil from drying out.
  • Citrus don’t like standing water.



  • Full


Nagami Kumquat Fertilization:

  • The tree is more susceptible to zinc deficiency that other citrus.  However, like all citrus it also needs other micronutrients.  I add micronutrients to the topsoil in the spring.
  • I also provide a balanced fertilizer throughout the growing season (4x/y).  In general, I have noticed that  all of my citrus appreciate an assortment of different types of fertilizers throughout the year.  Throwing in a random assortment of organic fertilizer whenever you have it is always appreciated (compost, worm castings etc).



  • Because it goes into a dormant non-growth stage sage in the winter, the plant is one of the most cold tolerant of all citrus. I have read that the Nagami Kumquat is able to withstand temperatures as low as 14F!  But I wouldn’t recommend pushing that chilly temperature limit.
  • For more information about the lowest temperatures that you can expect in your area, check out my article “Climate Zones: What can I grow in my yard?”



Susceptible to the usual citrus pests such as the citrus leafminer.

For more information, please see my 6/20/13 post for diagnosis and treatment of the Citrus Leafminer. 


Food use:

  • If you like sour, you can just pop them in your mouth peal and all.  If you eat the fruit all at once it is a powerfully and intense hit to your taste buds. When I eat the Nagami Kumquat fruit this way, it almost reminds me of Gatorade gum.
  • Some people will just eat the rind because that is the sweet part and toss the sour juicy center.
  • Nagami Kumquat fruit is also used to make preserves, marmalade and candied.
  • Garnish drinks/cocktails.
  • The sour juice can be made into a lemonade like drink.
  • Cut the whole fruit into thin slices for salads.



About Thomas Osborne, MD

Dr. Osborne is a Harvard trained Radiologist and Neuroradiologist who loves to share his insight about medicine and gardening.


  1. I planted a Kumquat for the first time last year. Fukuqui or something. Anyway, After doing well for a few months, it wilted and died I thought. Reading your article I guess it went dormant and perhaps it will spring back to life now that the weather is warmer in San Jose. I noticed that water drains away fast but I suspected it was because there was a Gopher hole right under the roots. The Mandarin orange right next to it, is still thriving and never lost its leaves in spite of the early cold snap we had in Dec. So I look forward to the next few weeks to see if my Kumquat comes back to life. I have already bought another Red Baron Peach to replace it if it dies. The Red Baron is to keep the JH Hale Peach company!

    • Thomas Osborne, MD

      Hey Sateesh
      Yea, Kumquats do slow down in the winter. As a result, they don’t tend to put out new growth in the colder months-and it is this new growth that is most sensitive to cold damage. Because of this particular growth pattern, Kumquats are more cold tolerant than other citrus.

      However, Kumquats don’t go dormant like your peach or apple trees do. In the winter, Kumquats should still have lots of leaves. In fact, my Kumquat trees are currently packed with fruit.

      Therefore, if your Kumquat is looking wilted, I fear that something is more concerning is going on. The nearby gopher hole could potentially be the sign that bad things are happening to your Kumquats roots. I have seen gophers take out an entire tree and leave an adjacent tree of similar size and make untouched. Sadly, I have lost many trees to those rodents.

      • You’re probably right Tom, but just in case, I dug up the Kumquat and planted it in a new hole with lots of mulch, top soil and fertilizer. The root ball still looked alive so there is hope yet. I replaced the Kumquat with a Red Baron peach which is right next to the JH Hale so pollination should not be a problem. I am eager to see results in the next few months. Will keep you posted. Thanks for your advice and support.

        • Thomas Osborne, MD

          Good job Sateesh. Your doing exactly what I would be doing.
          I would also err on the side of over watering in this critical time.
          I am sure you have already done this as well, however, I would also do a close inspection for bugs, those suckers can do more damage than many give them credit for.

      • Hi, I don’t care for the taste of kumquats but I love the beauty of the tree in my front garden. Question: do I need to pick the fruit once it’s ripe or can I just let it stay on the tree u till it falls off? This fruit has been on my tree since last fall!

        • Thomas Osborne, MD

          Hey Linda
          They are great looking trees.
          It is also totally fine to let the fruit hang on the tree.
          However, I would do your best to be diligent about picking up the old fruit off the ground… dropped fruit of any kind can attract rodents and for citrus, the old fruit can cultivate fungus that then spreads elsewhere.

  2. Two months after bringing my very leafy, full green Kumquat tree into a constant ( no lower that 55′ ) temperature home, all the leaves have fallen of. I have not fertilized at all. there are 10 green fruit on the tree. Is it dormant or dying…..? No gophers, no other plants failing in home…..can You help…?

    • Thomas Osborne, MD

      Hi Paul.
      That is a sad story.
      I am not exactly sure what is going on but there are a few possibilities to consider.

      If your tree is at the ground floor, then it might be colder down there then one might expect. Cold air is heavy and collects down low, esp at night when there is not a lot of movement and it is extra cold anyways.

      Potted plants dry out easily and winter air is often dryer than any other time of year.

      Root damage:
      Moving a big potted plant around can shock the little root hairs. These little hairs do most of the work for a plant and damage to them can sent a plant into a tailspin.

      Plants dont like change. A change in sunlight in addition to any of the above can just upset a plant. A combination of many small changes can add up to a big deal.

      There are likely more possibilities to consider, but its hard to tell without being there.

      What to do:
      Remove all of the fruit. They will only suck more energy away from the plant.
      Watch soil conditions closely.
      Keep plant in a safe place above ground level.

    • I had a similar leaf drop situation with both a mature tree and a new transplant. In my case I suspect the problem was due to water, as the leaf dropping on both trees occurred within a couple of days following a deep watering. I realize that citrus do not like to “get their feet wet”, but in both cases their was no standing water visible. Both plants are now making a come back but it has taken several months. How can I determine how much water to give to my plants? Is there some sort of reliable meter available?

      • Thomas Osborne, MD

        Hey Lori
        Your absolutely correct that citrus do not like to get their feet wet with standing water. This causes root rot.

        However, the roots are totally fine being surrounded by moist soil.

        For example, most winters in Southern California are wet… very wet.
        It can rain hard for days without stopping.
        The citrus trees that are planted in well draining soil do absolutely fine and in fact thrive with this type of heavy watering.
        The key is that the soil is well draining do they dont get water logged.

  3. Hello
    I am doing research on Kumquat fruit.
    How do you know this fruit is and what it is a sign of maturity.
    If you are able to make the resources available to me please thank you

    • Thomas Osborne, MD

      Hi Arsalan
      Thanks for the note.

      Optimal Kumquat fruit ripeness:
      To some degree, the optimal time for fruit ripeness depends on your personal preference.
      The longer you wait to pick the fruit, the sweeter the fruit gets.
      However, if you wait too long then the fruit can fall off the tree and/or shrivel up.

      For me, I find the best time of ripeness is when you have the following:
      * The fruit is orange in color… the darker the fruit the sweeter.
      * The point where the fruit is attached to the tree can sometimes be a tad green and still be good. However, the fruit will be sweeter as that area turns yellow.
      * The fruit will be less firm to the touch as it hits maximum sweetness.
      * The fruit will pull off the branch fairly easily when optimally ripe.

      Would you like more information regarding your resource question?


      • Hi Tom
        Thank you Tom for the good tips I’ve provided.
        Sources can provide me with a debt that is acceptable in scientific research I can put it in my research.

        • Thomas Osborne, MD

          Hi Arsalan

          The majority of the information I have about growing Kumquat’s has been obtained from two major sources:
          * Years of personal experience
          * Discussions with nursery owners and local growers.

          Unfortunately, this is not typically the group of people who write scientific papers on these topics.
          There are some commercially available books that are nice to use as a reference, such as:
          http://www.amazon.com/gp/product/0376039183/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=0376039183&linkCode=as2&tag=tastylands-20&linkId=WHFT4W5QVZBJA3YW“>Western Garden Book of Edibles: The Complete A-Z Guide to Growing Your Own Vegetables, Herbs, and FruitsReply

          • Hi Tom
            Do you think you can or using image processing techniques using near-infrared investigation to determine Kumquat?
            Thank you very much

          • Thomas Osborne, MD

            Hi Arsalan
            That is a very interesting and advanced question.

            Basically Near-infrared is a form of light that we cannot normally see.
            This specific part of the electromagnetic spectrum is from about 800 nm to 2500 nm.
            With specific instruments that allows us to see near-infrared, we can tap into a wealth of additional information about something.

            What is it used for?:
            Near-infrared spectroscopy (NIRS) has a lot of scientific applications.
            NIRS is used in medicine, astronomy and agriculture (to name a few).
            Specifically, NIRS can be used to non-invasively determine the quality of food products ranging from fruits, grains, meat and eggs.
            NIRS can also be used remotely (from far away) to evaluate forests and soils.

            Ripe fruit:
            Since a ripe fruit is expected to have a specific near-infrared signature, then you may see differences with NIRS.
            The specific sensitivity range of your NIRS instruments would make a difference.
            Therefore, you would have to get the right NIRS tools with the correct sensitivity.
            Potentially subtle differences may be difficult to detect depending on the scale you are looking at.

            Scientific Papers:
            There are a lot of papers out there on this specific field of inquiry.
            Below are a few examples of the types of NIRS fruit articles that you may find on an internet search.




            Good luck!

  4. Hello
    I am doing research on Kumquat fruit.
    How do you know what the fruit is ripe and it is a sign of maturity.
    If you are able to make the resources available to me please thank you

  5. I had a great little tree foe 3 years that did wonderfully. Last year it started dying from the top down. I live in North Florida and we had no big freezes. Any ideas? The neighbors and I miss the tree. Plan to replace it.

    • Thomas Osborne, MD

      Hey Judy
      What a bummer. Sorry to hear that.
      Kumquats are one of the most cold tolerant citrus, so I also dont think it is from a freeze.
      Not sure what the cause could be at the moment… Do you happen to have any pictures?

  6. hi thomas
    I bough two nagami kumquat about two years ago and I transplanted them in our backyard. I live in vally in california. when i bought them they had many fruits, but since than they haven’t given any more fruit and the leaves fall. I been giving them chicken manure, and stem manure and vitamin b but they are still only having some leaves.

    • Thomas Osborne, MD

      Hey Sean
      Thanks for the question.
      Sorry to hear about your kumquat leaf loss.

      There are many potential causes of major leaf loss.
      However, in my experience most all of them relate to plant stress and quite often that stress is some how related to water/the roots.

      A few more-specific things to think about.

      Transplantation shock:
      Major leaf loss can be a sign of transplantation shock.
      Transplantation shock usually occurs as a result of major root damage during the relocation from nursery->container->ground.
      If severe, this can result in many years of struggle (sometimes plant death) as the plant tries to recover.
      Therefore, I go out of my way to avoid this potentially deadly situation (see article link below for more info)

      Not enough water:
      Not watering enough (esp in sandy soil) can also lead to leaf loss.

      Too much water:
      On the other hand, with too much moisture, the roots cant breath or absorb nutrients.
      If the soil is chronically wet, this can lead to fungal infection and potentially deadly root damage.

      Not enough sun:
      A sun starved plant will look leggy and may be lacking leaves.

      Gophers can obviously eat roots. If the eating is not complete, the plant can be left to struggle supporting the remaining leaves with less ability to get water to them. And gophers can be so sneaky that you may not easily see their holes.

      Infections (aphids, scale, etc) can suck a plant of its resources and it may not have the energy to make leaves.

      (A picture of your tree might help if you were able to post somewhere and provide the link).

      Hope this helps a bit.

  7. I’ve been having my nagami kumquat tree in a pot for the last 5 years. It has been fruitful year around. I have it positioned directly under a valley of my house so it gets plenty of water. I’d like to transplant it and put it in my yard. My soil is mostly clay. Should I do that or would it be a good idea.

    • Thomas Osborne, MD

      Hey Bruce
      Thanks for the great question.
      Very insightful of you to be asking about transplanting.

      A while back I wrote an article on the best way to transplant/plant (link provided below).

      That should cover almost everything for you.

      However, that article was written with the assumption that the tree is being transplanted from a nursery container. Therefore, three additional thoughts come to mind that you might face.

      1. Container type:
      If you have your tree in a clay pot (or other container), it may be more challenging to get the plant out of the container safely. Best advice is to go slow and try to keep the root ball intact as much as possible. I personally err on the side of sacrificing a container/pot for the health of the roots… but that is just me.

      2. Root bound:
      If you see roots swirling around the edge of the container, it is probably root bound. This happens to most plants that have been in the same container for a few years. Once the root ball is safely removed from the container and in place, try to gently unravel the roots that are coiled up on the outside. The idea is to get the roots pointing outward so they can get a strong footing.

      3. Acclimatize.
      If your tree is currently in a some shade, and you want to plant in full sun then you might want to play it safe. I would first gradually move the tree into the sun so it can adapt to the new conditions.

  8. Hey Thomas,
    Could you help an absolute gardening beginner? I have just bought a Kumquat tree in a pot. After reading your earlier posts I am convinced my tree had experienced some significant shock and I look for best ideas to speed up its recovery. I also wonder how old the tree might be.

    It is about 1.5 m high (measured together with a pot). The trunk is aprox. 3 cm in diameter.
    There were some deformed leaves and I cut them off (usually 2-3 at the pick of the stem, I also removed a few broken in transport – altogether about 10-15 cuts). Could be moths at one of the leafs, but I am not sure. I sprayed the plant well with water, inspected all the leaves, and positioned at my balcony (sunny, open). The weather is very hot these days (up to 32 C). And the soil came dry form the gardener, so I watered it well before night adding small dose of organic fertilizer. I repeated watering in the morning and again in the evening and probably overdone a bit. The soil is heavy and soaked, although no water shows up from the drainage holes.
    My concern started when I notices a few small leaves on the floor, which must have fallen today, and all the flowers and flower buds also gone (they were very few, sth like 5-8).

    What would you recommend to do since now on to ensure best chances for the poor tree?

    • Thomas Osborne, MD

      Thanks for the note.
      I will try to help anyway I can.

      Tree age:
      It is really difficult to accurately determine tree age by height alone.
      Conditions play a major role in tree growth. For example, you might have a young tall tree or a small old bonsai.
      If you have not planted the tree from seed then the other option is to cut the tree in half and count the rings.. but that kindof defeats the purpose.

      You mentioned moths on your tree.
      I would look into this further. There are various infections that can look like little moths and they need to be addressed. This infections can suck the life out of a plant. This could be related to the stressed condition of your plant. You also want to spray your citrus for leaf miner, this same spray will remove the other unwanted sap-sucking guests. Check out an article I wrote on the topic for more details.

      Other stress considerations:
      Growing in a container is difficult. The soil dries out fast, the soil temperature flux throughout the day is more intense. An automatic watering system can be a big help and save you a lot of hassle. Here is a Link to a complete patio type of watering kit on Amazon. http://amzn.to/1JnMyJH

      Fertilization is more difficult for container plants. I generally recommend organic fertilizer for potted citrus because it is more forgiving to use. Amazon has a bunch of options available (from reasonable http://amzn.to/1CHrhhk , to expensive http://amzn.to/1SsyOSV).

      Even if you do everything correct, a tree will eventually get root bound in a container-which will cause most all trees to decline significantly in health. Additionally, roots may plug up the drainage holes causing overly moist conditions. Furthermore, a potted tree can also topple over adding to the stress on the whole plant from the traumatic pact. Transplanting to a large container helps all of these issues.

      Hope this helps!

  9. Hi Tom,

    Many thanks for your rich and prompt answer. It helps a lot!

    In fact the deformed leaves have looked like those in the pictures by your leaf miner article. I did not see the white “trails”, but the rest is really very similar. Thus I will definitely search for some kind of spray available in Europe and matching your suggestions. The same applies to the fertilizer – on the list already.

    I will skip the automatic watering system, as I have no water supply at the balcony. I need to stay on the “manual”, but by now I know the soil in this pot holds the water more than any other of my few plants.

    I intended to move the tree to a bigger container anyway, but my question about this action are:
    – Should do it asap, or wait some time to let the tree take a break after already experienced stress?
    – Should I use similar soil as the one the tree has now (thick, dark, solid and holding water) and just ensure a 5-7 cm deep drainage at the bottom with keramzyt balls or stones, and sizable holes in the pot bottom?

    I hope I do not overuse you with the above new questions.

    • Thomas Osborne, MD

      Hey Katarina
      No problem, very happy to help.

      When to transplant:
      Good question. But not an easy one to answer.
      To some degree, it likely depends on the type of stress the plant it experiencing.
      If it is an acute stress (lack of water, bug infestation, traumatic injury), they it makes sense to wait a bit for the plant to recover.
      If it is a chronic problem (being root bound, poor container/soil) then you need to fix that environment for recovery sooner than later.

      Soil type:
      If you talk to someone who is really into soil science, they will tell you all kinds of nuanced details of different soil types… And many of those different soil types look the same to the average person.

      Soil for container citrus:
      Disclaimer: since I havent grown citrus in containers, I do not have direct experience. Perhaps another reader can add some wisdom. None the less, I do have some general ideas for you.

      For container general plants (not cacti), many people suggest a soil that holds moisture (with things like peat moss) bc the soil in containers tends to dry out fast.
      However, if you are planting in the ground, too much peat moss is not typically what you want your citrus roots to be growing in bc it may promote overly damp conditions.

      I have even heard of specific soil blends made just for potted citrus… However, I have not actually seen these alleged soils in stores.

      So if it was me…
      I would probably just get a soil blend made specifically for potted plants.
      But then again, I might just mix something up with what I have on hand.

      Hope this helps.


  10. Hi Tom,

    Thank you so much again.

    I guess I will observe the tree for some days and see. I would bet rather for the acute stress of the a bit harsh relocation and my inexperienced treatment. The garden center, where I bought the plant looked rather professional (so hopefully it was well treated there) and if there is a leaf-miner attack – I would not say it is massive.

    I will look for the special for citrus soil. Perhaps I will find it. I hope a better water balance will be a good start.

    Once more: great thanks for all your expert suggestions,

  11. Hi Dr Tom

    I live in Northern California with very hot summers so I planted my kumguat on the west side of the house but it gets shade during the hottest part of the day. It’s been in the ground about four months and appears to be doing well …new growth and had lots of flowers. However, after the flowers the little “nubs” left on branches, have started to dry up and drop off . Is the tree still in transplant shock from planting ? Or something else ? I think it’s getting the right amt of water ….but maybe to much ???

    Thank you for giving your time to stumped gardeners like me 🙂


    • Thomas Osborne, MD

      Hi Elaine
      Thanks for the note.

      Its hard to tell without a picture, but…
      When you say “nubs” do you mean the central part of the flower that is left behind after the petals fall off?

      If so.. then it sounds like the fruit might be aborting early. This is pretty common for a newly planted tree. Basically they are diverting energies to new roots and recovering from the move.

      Anyhow, if a tree does not do this on its own, I basically recommend that you do it. Pulling off off the fruit from young and/or newly planted trees will encourage the plant to spend its energy more responsibly during this critical establishment stage.

      Side thoughts:
      Too much water or too little water may result in many different plant symptoms.
      The following are some common considerations.
      Both too much and too little water may result in yellowing of the leaves. However, yellowing is more classically associated with too much water.
      Too little water often results in withered-droopy leaves and/or dropping of leaves.

      Hope this helps.


  12. Dr. Osborne,

    What causes Nagami fruits to be dry and mealy to the taste vs. juicy and crisp? Mine is a grafted plant cultivated on a container.

    Thank you for any answer you may offer.


    • Thomas Osborne, MD

      Hey Ron
      This is a great question.
      Citrus can become dry and pithy for a few reasons.
      (this may sometimes be referred to as “granulation”)

      Young trees that are not established enough, trees grown on vigorous rootstock, drought/water stress, and poor fertilization can all be causes or contributing factors.
      Even overripe fruit, and extended warm growing season has also been reported to be a cause.

      If your tree is young, this should get better over time.
      If not, then review the other causes and adjust to optimize.

      Hope this helps,

  13. I live in Northern California on the bay side of the San Francisco Peninsula and have a kumquat tree that had lived in a pot for several years. I planted it in the ground about 2 years ago. It loves it there, but has now reached the eaves of the adjacent porch and is bending for more space. I need to move it to give it more room. When should I do this?

    • Thomas Osborne, MD

      Hi Roberta
      Great question and good idea to move your Kumquat.

      Best time of year for citrus transplantation:
      In my experience, the best time to move citrus is when it is cool and wet… basically now (Winter/Fall).

      Additional steps to ensure transplantation success:

      I dont generally purne citrus unless they are growing in the way or have dead branches
      However, at transplantation I do prune a bit more than usual. I remove the branches that will be in the way during the transplantation process (mostly lower branches). I also remove any fruit and flowers. This will put less strain on the tree.

      Root ball:
      The bigger the root ball you can get the better.
      Putting some cloth (burlap/old sheets/etc) around the rootball when you are trying to move it will reduce damage to the roots (the tiny-microscopic hairs on the roots that do most of the work get sheared off with movement).
      This root cloth also makes it easier to move the tree.

      If you can transplant into a gopher cage that is great too.
      How to build a gopher cage

      Additional steps:
      Then water the heck out of the tree after transplantation.
      More info on my most effective method of planting via this link: Best planting technique: 7 important steps

      Best of luck,

  14. Hi, you say a cumquat tree doesn’t go dormant? So that means that there’s no hoe for one that lost its leaves in a cold place then?

    • Thomas Osborne, MD

      Hey Zoe
      Sorry to hear about your kumquat tree.
      As you may know, kumquat trees are citrus trees and citrus trees are not deciduous.
      (Deciduous means “falling off at maturity” and it is typically used in order to refer to trees or shrubs that lose their leaves in the fall/winter).

      So a healthy kumquat tree should not loose all of its leaves.
      However, I have seen some citrus trees loose all of their leaves for one reason or another and sometimes the tree recovers.
      Most of the time this happens for some known reason such as cold weather, dehydration, disease, girdling or poor planting techniques. Sometimes it can be a combo of things. For example, I lost one of my first Meyer lemon trees because I planted it too deep and the soil around the base of the trunk caused rotting that then basically girdled the tree.

      I have a friend that is a 3rd generation citrus grower. In the past we have talked about sudden citrus leaf loss. In addition to the above possibilities, he said it sometimes just happens without a clear cause. He said that his dad called this “leaf shatter.”

      Anyhow, bottom line is that it is not a great sign but not necessary a death sentence.

      One way to tell if you have a chance of survival is to scratch the thin bark layer of a branch. If you do this and still see green (the cambium) then the tree/branch is still alive.

      Good luck.

  15. I live in England and have a kumquat tree growing in my garden. It was planted by the lady who had the house before me. She grew it from seed. I have lived in my house for over ten years and am about to totally redesign my tiny back garden where the tree grows. I would like to know how long kumquat trees live. As I don’t want to plan my garden round a tree that may die in a year or two.

    • Thomas Osborne, MD

      Hi Beatrix
      Great question.

      As for any organism, an individuals lifespan is dependent on environmental factors, disease, and overall health etc.
      However, in good conditions, most reports that I have seen say they live to about 50 years.


  16. My Nagami Kumquat tree has been blooming for 3 – 4 years now but every time that the tree blooms all the flowers fall and I have had just some few fruit. Every Summer the tree has hundreds of flowers and lots of bees come to pollinize them but the flowers don~t make it. The tree is very healthy and free from any type of diseases or insects. I spent hours this Summer to monitor the pollinization by the bees and thought I would have lots of fruit but again all the flowers dried and fell. I have searching on line what would cause this problem but so far have not read anything helpful. I hope you can be my tree doctor. Thanks a lot for taking your time to respond each comment. I have read them all.

    • Thomas Osborne, MD

      Hi Ellie
      That sounds like a frustrating situation.
      A few questions come to mind:

      How old and big is your tree?
      How often do you water and fertilize?
      What growing zone are you in?
      What do the leaves look like (color/pattern of green/yellow)

      • Hi Dr. Osborne! Thanks for you quick reply. My tree is about 8 years old and is 11 feet tall. I water it every other day in very hot days. When it’s cooler I water it every 3 days. Each time I give it a lot of water. I don’t fertilize it. I put some chicken manure a few times when the tree was still young. I believe I am in climate zone 15 or 16. I live in San Francisco Bay Area. The leaves of my Nagami are dark green and glossy. The tree is very lush and looks very healthy. Thank you in advance!

        • Thomas Osborne, MD

          Well it sounds like your tree is really healthy and of the right age to produce.
          Surprised to hear you have dark green leaves with minimal fertilizer; you must have really great soil.
          That is a quandary Ellie.
          How much sun does it get?
          Do you have any pics?

          • My tree gets a lot of sun all day.It is surrounded by plum trees and a mandarin tree but it still gets full sun all day.
            I was there today making sure the bees had access to the blossoms because the spiders keep spinning their webs threatening them. The tree is blooming again since the Summer blossoms didn’t make it. I also saw dozens of yellow leaves in the center of the tree. I believe that is because of the fall season. Am I right?
            How do I send you the pictures of the tree? Thanks a lot for taking your time to help me Dr Osborne!

          • Thomas Osborne, MD

            Do you have some sort of social media account to share pictures on (Twitter, Instagram, etc)?

          • I have Facebook only. Does it help?

          • Thomas Osborne, MD

            Sure, if you can share a pic through FB than that would be great.

          • Dr. Osborne
            Sorry for taking so long to send you the pics of my tree. We’ve have had lots of rain in the past 3 days. To see the pictures please go to my Facebook at Eliane Eme Sato. Thanks again!

          • Thomas Osborne, MD

            Hey Ellie
            Believe it or not… I dont have a Facebook account.
            I know, everyone has one but me.
            Is there a way for me to see your Facebook pics without having an account?

          • Facebook is not for busy people like you, believe me. lol. Anyone can see my pictures. They are pubic now. Just enter Facebook and open my account by typing Eliane Eme Sato and you will be able to see them. Sorry for the difficulty and thanks again for helping me.

  17. Dr. Osborne,
    I just received a Nagami kumquat as a gift. I live in Northern Michigan, zone 3! Obviously this will have to be an indoor plant. The threads I read in this blog don’t seem to bode particularly well for the long term survival of this plant. Any advice?

    The tree is about 3 feet tall and is in about a 2 gallon disposable plastic container. It looks very healthy and even has some fruit on it.

    Our house is extremely dry in the winter even though we run a humidifier constantly.


    • Thomas Osborne, MD

      Yea, good luck.

      If I was in your position, I would:
      +Transplant into a larger container.
      + Find a nice spot for it near a sunny South facing window.
      + Do your best to keep up with the watering in the winter. It will require a lot bc the soil will dry out fast.

      Good luck!

      • What kind of soil should I use when I transplant? Is regular potting soil ok?

        Should I do anything special when I water? For example when I water my spider plant (the only house plant we have), I water it with a liquid indoor plant fertilizer already mixed in. The plant seems to like it, as it has flourished for many year!

        Should I get a pot that has drainage at the bottom? Maybe put some stones in the very bottom so the roots aren’t sitting in water?

        Thanks for being patient with a novice!

        • Thomas Osborne, MD

          Hi Anne
          Good questions

          Potting soil:
          I would use good (regular) household potting soil.
          There are special formulations for citrus plants that I never use. I guess those would work too but those are typically for the garden and tend to be a bit organically-stinky for the home. The soil formulated for household plants seems to have eliminated that smelly side effect. Water and fertilizer are your main challenges.

          Yea, citrus love fertilizer. However, it is easier to overdo it with potted plants than outdoor(in the ground) plants. Therefore using a frequent amount of dilute fertilizer (like you suggested) is a great way to go.

          Yep, drainage is key. Citrus (and most plants) hate sitting in standing water.

          One more thing…
          Of all the citrus, the kumquat seems to be the most tolerant to chilly air. However, they still dont like freezing temps. Therefore, its important to accommodate for that when growing inside. Drafty windows can be a problem so make sure to seal those up, esp ones close to your sun loving plant.

          In addition, cold air is heavier than warm air. Therefore, there is a temperature gradient in every room with the hottest air at the top and coldest air at the floor. If your plant is positioned on the floor then it will be sitting in a pool of the coldest air. Raising the plant up on a stand or putting on a sturdy table will help. However… sturdy is key. If the plant tips over and hits the floor than the shock to the roots, etc could be bad news.

          Sounds like you are on a great path.
          Good luck!

          • Speaking of chilly, we keep our house at 61 F in the winter. The kumquat is going to have to deal with that! lol

  18. Thanks for ALL your great posts here! Planting a new to us 7′ talll Nagami Kumquat tree in a few days, we are in Central East Coast Florida.

    I wanted to add, besides how much I love Kumquats! First had them in London to ‘clean the palate’ during a multi-course large English traditional meal. Cleans the greasy food from your mouth and Gallbladder, making it easier to digest. (great to eat after greasy foods)

    I also use the skins only of the Kumquat to dry in my dehydrator. This is the BEST Orange ZEST ever! Sweet peel is perfect!

    So looking forward to having my OWN supply source in our backyard!
    When eating the Kumquat, yes the bitter takes hold fast, BUT as you chew and break down the peel the taste grows and gets better and better with a ‘great’ finish!

  19. I just bought a small Nagami Kumquat and will be transpanting it tomorrow. I have a couple citrus trees now. The calamansi is established and is fruitful. The blood orange has been in the ground for about 2 years. The leaves were really curly and affected by insects so I spent some time pruning the bad leaves off. I’m not surprised the growth is slow and there are no blooms. Other than that it is healthy. By having multiple types of citrus within close range of each other, will the fruit themselves be hybrids or some kind of mutant (lol) because of pollination by bees? BTW, I live on Maui. All trees are growing in full sun.

    • Thomas Osborne, MD

      Hey Cynthia
      Great question.

      Cross pollination is great for fruit productivity.
      However, cross-pollination wont make the fruit from a tree a hybrid… The fruit will still be true to the type of tree it grew on. However, the seeds from that fruit that is cross-pollinated may produce new and interesting hybrid fruit.


  20. I have a Nagami kumquat it is ful of fruit but I’ve noticed that it is dropping the fruit before it is mature. Could you tell me why it maybe doing this. I purchased it back in the springtime. It is also still having blooms. I live in the Lowcountry of South Carolina it will remain a container plant. Thank you

    • Thomas Osborne, MD

      Hi Annette
      Thanks for the note and great question.

      Premature dropping fruit is often a sign of either plant stress or young age of a plant (or both).
      If your plant is in a container, then it is going to experience more stress than other plants whichis largly the result of a greater flux in soil moisture and temperature. Standard nursery black containers are particularly challenging because they can get really hot in the sun. Another problem is the plant getting root bound and that will cause all kinds of problems which can make a plant really ill.

      So what do you do..?
      I am not totally sure that being in a container is the problem, but what you described is a very common problem for container plants.
      I would water the heck out of it. Really soak it. And do that at least once a week or more as needed.

      In the Summer I might hold tight because Summer is not the best time for transplanting.
      However, if you wanted to get to the root of the problem (so to speak) then transplanting would be the way to go.
      After a heave watering, wait a few days and then carefully plant it in a larger container… or better plant it in the ground if you can. Then soak the heck out of it again.
      I have some advice on successful planting via this article and link below
      Best planting technique: 7 important steps

      Good luck!

  21. My 4-year kumquart tree is in a pot on a patio outside. It bloomed in August this year, and now it has tiny fruit. I am afraid the fruit will not ripen before it gets cold. Should I bring it indoors when it gets cold? i live in Seattle area, zone 8b.

    • Thomas Osborne, MD

      Hi Olga
      Thanks for the question.
      Kumquats are among the most cold tolerant of all the citrus.
      If you have successfully be able to keep it outside all year, then I would continue.
      Watch for cold spells and protect from extremes when needed.
      The following link will take you to quick article on how to Prepare for a cold snap that might help.
      Of course, since your plant is potted, you can also roll it inside when needed on those extra cold days.


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