Shop Products
Houzz Logo Print
tomtan_gw

KumQuat yellow leaves

TomTan
10 years ago

Can a citrus expert take a look of the attached picture recommend a better fertilizer? Usually I get my fertilizer from Home Depot or Lowes.

I live in WA state and I have this KumQuat plant for years. I re-potted the soil two years ago and then the leaves started to turn yellow since then. So I added acid based fertilizer (for Azalia) & fish emulsion, and it seems to boost the leave growth but the new leaves are still showing yellow.with green mixture. I leave the pot outdoor during summer and move it in house during fall and winter. Any idea what the plant is missing? Maybe I need to re-pot the soil or can you recommend a good fertilizer for KumQuate?

Comments (8)

  • poncirusguy6b452xx
    10 years ago

    Kumquat trees have a zinc and iron deficiency problem especially if they are grafted to poncirus trifoliata. What I have found that helps a lot is adding a tablespoon of vinegar to a gallon of chlorine free water with miracid 30-10-10 at half strength every week. I water as needed. Some times more than once a week. I have a mix of the same but with out the vinegar that I foliar feed 3 times a day Otherwise your tree looks very nice. But if you want, i'll trade you trees. lol.

  • johnmerr
    10 years ago

    See the green "Christmas tree" in the center of the leaf with yellow edges??? Classic Magnesium deficiency; you can add Epsom Salt (Magnesium Sulfate) to fix it. I put MgSo4 (Magnesium Sulfate) on all my garden citrus twice a year... I put it on my roses at the same time. My field Meyers get a fertilizer with 2% Magnesium; and still I put a chelated mineral mix every July for "insurance".

  • TomTan
    Original Author
    10 years ago

    Thanks guys! I'm going to give both suggestions a try.

  • poncirusguy6b452xx
    10 years ago

    Johnmerr Tanks.> I believe your reply answered questions of mine.

    Steve

  • johnorange
    10 years ago

    I don't know what kind of kumquat you have but the leaves look HUGE compared to those on my trees. I appreciate the reminder of the use of epsom salts as I believe I have a similar problem.

  • turtlegreen
    10 years ago

    @Johnmerr

    What concentration of magnesium sulfate do you use? Or do you simply sprinkle the epsom salts around the drip line of the plant?

    Thanks.

  • meyermike_1micha
    10 years ago

    Jage....If you are going to be using Mg, will you also compliment it with a Calcium source?

    Please be careful....If your fertilizer already has this nutrient in it, something else is causing your Mg problem.

    Applying Epsom salts when Mg is not deficient needlessly raise the level of dissolved solids in the soil (solution), making it more difficult for the plant to take up water and the nutrients dissolved in water, it can also create what is called an antagonistic deficiency of Ca. Ca and Mg need to be present in a ratio somewhere in the 2-4.5:1, Ca:Mg range. When that ratio becomes skewed through the addition of only Ca or only Mg, the other nutrient (in this case, Ca) is more difficult for the plant ...

    What's your tap water at? Just curious..

    Mike

  • turtlegreen
    10 years ago

    Thanks for your reply. I'll take a look at the fertilizer I'm using and see what it lists. I've just been using a 20-20-20 general plant fertilizer from Miraclegrow (I called 6 different nurseries in my area (Denver) and no one carries fertilizer specific to citrus). However, I've used it very sporadically.

    All the leaves of my Meyers lemon were turning yellow so the first thing I did was, since it's been in the same pot for over 6 years, was to root prune and add new soil. That was over two weeks ago and the tree actually looks a ton better. There's only a couple leaves with a little yellow left and the rest of the leaves are really greening up. It also got a good soaking as we had 15 inches of rain in about three days!

    It's chock full of small lemons and I want to be able to "reap the harvest" and have been doing some research on how to properly care for potted citrus and came across the notion that people periodically water their citrus with epsom salts. So I thought I'd give it a go.

    However, you bring up good points so I'll probably hold off on the epsom salts and try to be more diligent in regular fertilizing.

    I have no idea the calcium, magnesium, or alkalinity concentrations of my tap water as I've never tested for them but I do know the tds is generally low, usually in the 30-40 ppm range.