Schedule for Fertilizing Mangos

[fruitlovers]

Thinking of adding potassium fertilizer to my mango trees. What is best season to do this and how much is applied to each tree?

[phantomcrab]

Thinking of adding potassium fertilizer to my mango trees. What is best season to do this and how much is applied to each tree?

Oscar:
I asked Richard Campbell about this and here's his reply:

Correct, only sulfate and 2 to 3 times a year. liberal sprinkling under drip line. 227 g K per 1 in trunk circ. more or less.

So use only K₂SO₄, not KCl based fertilizer because of mango's salt sensitivity. Since you get rain throughout the year, you should probably spread it throughout the year.

[Jackfruitwhisperer69]

Hi Oscar,
I once asked Dr. R. Campbell about the Nitrogen on You tube....

so when is the right time to fertilize the mango tree with N ?

crazyamazondude 11 months ago

Reply-We dont really add any N. That comes from the mulch around the tree. We add K, twice a year. Once when the blooms first come out and again when the fruit begin to form.

fairchildgarden in reply to crazyamazondude 11 months ago

[fruitlovers]

Thanks Richard and Steven for the answer to my question.

[zands]

Thanks Richard and Steven for the answer to my question.

One of the Broward posters said he was fertilizing his older mango trees with 50lbs potassium after harvest. That was it. That 50lb bag of K sulfate costs about $25 in South Florida.

But with your higher rainfall you should divide up your potassium doses. You think? If you have heavy mulch around trees will you throw the K on top of the mulch? Then it takes a while to get down there as some K may get incorporated into the mulch and not be released to plant roots until the decaying mulch reaches them.

My opinion is use NPK for younger trees to get them off to a good start. Say up to 4-5 years old and fruiting well. Then straight potassium can be used though I think some NPK should still be used same as done in mango orchards around India and the third world.

I understand the Fairchild fertilizing philosophy but don't agree with all of it. For all I know they say straight K for young mangoes, which is a big mistake, going by my experience. I bought that jive for my first few years and did not fertilize at all. When the trees would have grown faster with NPK with minor elements such as the 8-3-9 Excalibur sells

[phantomcrab]

Ditto here. My first year growing mangos I was stingy with the NPK and the trees' growth reflected it. Then I saw a PI tag that said to go much heavier for the first two years and now they are doing much better. I'll switch to the 0-0-22 when I'm getting consistent fruiting. I want good fruit, not giant trees.

[fruitlovers]

Ditto here. My first year growing mangos I was stingy with the NPK and the trees' growth reflected it. Then I saw a PI tag that said to go much heavier for the first two years and now they are doing much better. I'll switch to the 0-0-22 when I'm getting consistent fruiting. I want good fruit, not giant trees.

I think what you and Zands are saying is true in your sandy soil. But this mango grove i planted is in pretty good clay loam soil. I never applied nitrogen and they all grew great. So this will all vary a lot with what you're starting out with. I think potassium leaches out rapidly in rain? I think i will follow Zand's advice and stagger the application, rather than just apply at flowering and small fruit stage, as mentioned in Steven's post quoting Campbell.

[phantomcrab]

Yes. K will leach out very quickly in sand and less so in heavier soil. In heavy rains it will tend to run off in soil of less porosity.

[zands]

Ditto here. My first year growing mangos I was stingy with the NPK and the trees' growth reflected it. Then I saw a PI tag that said to go much heavier for the first two years and now they are doing much better. I'll switch to the 0-0-22 when I'm getting consistent fruiting. I want good fruit, not giant trees.

I think what you and Zands are saying is true in your sandy soil. But this mango grove i planted is in pretty good clay loam soil. I never applied nitrogen and they all grew great. So this will all vary a lot with what you're starting out with. I think potassium leaches out rapidly in rain? I think i will follow Zand's advice and stagger the application, rather than just apply at flowering and small fruit stage, as mentioned in Steven's post quoting Campbell.

You the Hawaii fruit master and are going to follow my advice??  I am honored     Most of the time I tuck fertilizer under my fruit trees mulch. But my scale is smaller than yours. Maybe to begin you tuck the K under your mulch. I just jam a fist full of fertilizer under the mulch and spread it around as best I can under the mulch. I will keep doing this.

But after initial K applications you, with your more extensive plantings. can get by wisely spreading it on top your mulch and letting the K reach tree roots in its own time

  I never applied nitrogen and they all grew great.

Not even animal manure? Anyways you and Fairchild can get by with no nitrogen and no NPK. Fairchild just applies K........ But every soil situation is different

ZZZZZzzzzzzz

[zands]

Ditto here. My first year growing mangos I was stingy with the NPK and the trees' growth reflected it. Then I saw a PI tag that said to go much heavier for the first two years and now they are doing much better. I'll switch to the 0-0-22 when I'm getting consistent fruiting. I want good fruit, not giant trees.

I could not agree with you more. I first planted in 2008. Years 2008,2009, 2010 I used no NPK because I followed Fairchild recommendations. In fact I also sent email to Dr Campbell and got same reply as Steve. That they just use 0-0-50 fertilizer which means (for the newbies) straight potassium with no nitrogen or phosphate

In 2011 I started laying down NPK according to the amounts listed on Zill nursery mango tags and am happier with the results. Zill tag recommendations can be read over here >>>>> http://farm7.static.flickr.com/6015/5905298900_05f84f80ee_b.jpg

The Zill recommendations for young mango trees is one tablespoon of high quality NPK fertilizer with slow release nitrogen and with minor elements....One tablespoon of this per foot of tree height. Apply this each month except for the cold and tree dormancy months of November, December, January. Read the Zill tag for more. In Florida we can get really good 8-3-9 NPK at Excalibur Nursery at a very fair price.

To generalize. Using only K is more for older trees that are fruiting decently. While NPK is a better bet for younger trees. Also if you want your tree to not grow so fast or large then minimize or cut out the nitrogen. If you have a large tree that is shading out others, then why feed it nitrogen?

Z

[fruitlovers]

Ditto here. My first year growing mangos I was stingy with the NPK and the trees' growth reflected it. Then I saw a PI tag that said to go much heavier for the first two years and now they are doing much better. I'll switch to the 0-0-22 when I'm getting consistent fruiting. I want good fruit, not giant trees.

I think what you and Zands are saying is true in your sandy soil. But this mango grove i planted is in pretty good clay loam soil. I never applied nitrogen and they all grew great. So this will all vary a lot with what you're starting out with. I think potassium leaches out rapidly in rain? I think i will follow Zand's advice and stagger the application, rather than just apply at flowering and small fruit stage, as mentioned in Steven's post quoting Campbell.

You the Hawaii fruit master and are going to follow my advice??  I am honored    Most of the time I tuck fertilizer under my fruit trees mulch. But my scale is smaller than yours. Maybe to begin you tuck the K under your mulch. I just jam a fist full of fertilizer under the mulch and spread it around as best I can under the mulch. I will keep doing this.

But after initial K applications you, with your more extensive plantings. can get by wisely spreading it on top your mulch and letting the K reach tree roots in its own time

  I never applied nitrogen and they all grew great.

Not even animal manure? Anyways you and Fairchild can get by with no nitrogen and no NPK. Fairchild just applies K........ But every soil situation is different

ZZZZZzzzzzzz

Hey, when you're right you're right!  I had the intuition before you mentioned it that this was best way to go about it, but you reinforced it. Also I've never applied K so far, so i'm guessing the trees are quite starved for it. Maybe after one initial post harvest application then i will move to Campbell's idea of just applying at flowering time. Ferts are super expensive here! So i definitely don't want to overdo it. I've never fertilized them with anything, totally zero, not even manure. They just got some grass clipping when i mow, not much really!

[FlyingFoxFruits]

I hear high phosphorous and low nitrogen can be beneficial for flowering mangoes.

any one try this with mangoes

[Mr. Clean]

I hear high phosphorous and low nitrogen can be beneficial for flowering mangoes.

any one try this with mangoes

Makes sense.

[bangkok]

I use bonemeal 2 times a year and also woodash 2 times a year. My tree's flower out of season and i love that.

I also use guano , dung and 0-0-50 in low amounts every few months.

[LEOOEL]

I use bonemeal 2 times a year and also woodash 2 times a year. My tree's flower out of season and i love that.

I also use guano , dung and 0-0-50 in low amounts every few months.

Very interesting and inexpensive fertilizing combinations. I like it and may try to innovatively immitate what you're doing, thanks for the info.

[Guanabanus]

Like all other plants for which essentiality of elements has been studied, mangos can be expected to need at least 16 elements, and probably 21 elements (maybe more), to grow and produce at their best.  [These five additional elements are in question:  probably directly essential are Silicon, Nickel, and Sodium;  indirectly essential to higher plants are Cobalt and Vanadium, because these are essential to nitrogen-fixing micro-organisms in the soil.]

Including complex sources of nutrients in fertility programs provides the trace elements.  Mulch, compost, muck, seaweed, lime and soft phosphate and other rock dusts,  when used in great variety, will cover your bases.  If you are depending just on mulch from plants grown on deficient soils, you'd best use a full fertilizer mix.

It is easy to get people off the phone by giving pat, formulaic answers, but soils and past cultivation practices are not the same, and the needs of different plant species are not the same, so expect, and practice, more complexity!

Sandy soils are not like muck soils, not like Rockdale soils, not like muck-over-calcareous-fill soils....

[fruitlovers]

What is the recommended amount of potassium sulfate to apply to large sized mango trees?

[Mr. Clean]

The University of Florida published a document describing a fertilizer regiment for mangos.

http://edis.ifas.ufl.edu/pdffiles/MG/MG21600.pdf

[bangkok]

I also use dolomite every year and  boron/zink drench once a year. I made a thick layer of mulch and used EM on that to improve the composting process. I put prawnheads in the soil, seaweed, ironchelate, worms and some b1 rooting hormone.

I try to keep it all organic with some extra 0-0-60.

I wrote here before the amount of 0-0-60 that mr Dizon likes to use (very high doses) and since i did that my trees give extreme sweet mango's. This year i will not use heaps of 0-0-60 but i empty the bbq under my tree's every time i use the bbq. That also gives potassium + some extra's.

[Tropicdude]

Just stopped by the local garden supply, and they had K2S04 , I purchased a small 1lb bag. these are coated, so I assume they are time release. no info on the package.

Anyway was wondering if someone could give me advice on how much to use for container plants, and the best time to use it.??


I read through this post, and noticed some discussion on the use of N on mangoes, and Fairchild's choice of not adding any other than mulch.

But that is the kicker,  they DO add N.  depending on what you use as mulch, you can gets loads of nitrogen from the decomposition.  some "green fertilizers" can actually give you too much nitrogen.  so what they are doing makes sense.  now if the mulch you use decomposes very slowly then It makes sense to add some.   but grass clippings, tree leaves etc. break down fast and release a lot of N.

[Guanabanus]

I agree about lots of Nitrogen being available from tree-surgeon mulch (containing lots of green leaves and green twigs).

I just re-read this thread and noticed the claim that Fairchild Farm puts a whole 50-pound bag of Potassium Sulfate around one large mango tree!!??  Maybe an ancient 'Haden' with a canopy 120' wide?  I didn't see the video, but think it likely that the recommendation was simply to BUY in 50-lb bags, and to sprinkle liberal amounts near the drip-lines.

[fruitlovers]

I agree about lots of Nitrogen being available from tree-surgeon mulch (containing lots of green leaves and green twigs).

I just re-read this thread and noticed the claim that Fairchild Farm puts a whole 50-pound bag of Potassium Sulfate around one large mango tree!!??  Maybe an ancient 'Haden' with a canopy 120' wide?  I didn't see the video, but think it likely that the recommendation was simply to BUY in 50-lb bags, and to sprinkle liberal amounts near the drip-lines.

I have a truck full of 0-0-50 on my truck bed right now. Getting ready to give my mangos some. How many pounds of it would you recommend for each tree for medium sized trees (15-25 feet tall)?

[bangkok]

Oscar you can see the website of mr Dizon fruittree's. He also uses big quantity's that i would like to be tested by some-one else first before i do it to my own tree's.

My tree who got the 400 gram 0-0-60 had the sweetest mango's that me and my wife ever ate. I gave it 400 grams when it had small fruits but mr Dizon adviced more.

[phantomcrab]

I agree about lots of Nitrogen being available from tree-surgeon mulch (containing lots of green leaves and green twigs).

I also agree. I mulched my mangos with 2-3 wheelbarrow loads of green mulch per tree in early July and all of them had an entire canopy flush about 3 weeks later.

[Triloba Tracker]

I found this thread after searching the forum for "0-0-50."

I too had read the Fairchild info about using this formulation for mangos, so I ordered some granular Sulfate of Potash.  I was looking for advice on when to apply and how much when I found this thread.

Now I'm a little bit conflicted about what to do. I see some are eschewing the Fairchild approach and instead recommending a more balanced NPK fertilizing regimen. I've read the UFL suggestions and the Zill tag. I'm hoping maybe y'all can help me make up my mind.

First, about our tree.  It's a Coshall in a 10-inch pot, and it's about 16 inches tall. We pugged it about a month ago, cutting about 3 inches. So far no new growth has occurred, but the top 2-3 nodes are swollen.

I checked in my tool shed and I actually have a few options on hand, as far as fertilizers:

• Hollytone organic evergreen and azalea food - 4-3-4 with 3% Calcium, 1% Magnesium, and 5% Sulfur.
• Jobe's Organics tomato and vegetable food - 2-7-4 with 7% Ca, 0.5% Mg, and 1.4% S.
• Osmocote slow release 14-14-14 pellets with no apparent minor elements
• Generic 10-10-10 fertilizer, in which the K is from muriate of K.
• and of course the 0-0-50 granules

My questions are:

• What should I go with?
• Suggestions on quantity?
• Is it too late in the summer (in Tennessee) to fertilize? High temps are sliding into the low 80's/upper 70's. At the moment we don't have a great winter home for the tree - just the sunniest window we can find. We hope to maybe get some lights and a grow tent, but that's TBD.