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Glenn Mango tree

Glenn Mango tree

Dear all,

2 weeks ago I purchased a Glenn mango in a 15 gallon container. Initially the plant was really healthy looking and green ,however just yesterday I notice that on some of the leaves, the edges are turning white or slightly bronzed. I have a feeling I over fertilized the tree. Just some background, for the past 2 weeks(once a week), I completely flood the 15 gallon container and then apply miracle grower liquid plant food.

Is the damage irreversible or will it recover? Also any advice on how I stood care for it i.e watering, fertilizing. I live in Fremont, Ca and have it in my patio.

thanks very much,


The following thread was started by Raj on April 27, 2009 at 7:37 am PST

Probably OK

I am not a Mango expert, I only own one Nam Doc Mi and not for long. Here is a little background and some suggestions. Hopefully someone else will chime in and confirm.
Mangos like HEAT, you will want to grow it in the full sun, not on your patio.
Mangos do not like wind.
Mangos like moist soil when the weather is hot but should be kept drier when the weather is cool.
Here is an excerpt from the CRFG website
Irrigation: Irrigation should start when the weather warms: February in the desert, April at the coast. Continue every one to two weeks, more often in light soils, nearly continuously in the desert, until the fruit is harvested. Irrigation may be discontinued when rains are sufficient to maintain soil moisture. In the greenhouse keep watered until the fruit is harvested, then reduce to the minimum required to avoid wilting. Watering is then increased after one to two months to initiate a new bloom and growth cycle.

Fertilization: Mango trees require regular applications of nitrogen fertilizer to promote healthy growth flushes and flower production. Chelated micronutrients, especially iron, are also often necessary. A feeding program similar to one used for citrus is satisfactory, but do not fertilize after midsummer. Organic fertilizers perform best, since the trees are subject to fertilizer burn. Young trees are particularly sensitive to over-fertilizing, but respond well to fish emulsion. Sandy soils require more fertilizer than loam or clay.

These are the actions I would take, but again, I am not a Mango expert.

Note that is says young trees are sensitive to over fertilizing.
You may not have damaged the roots but it is better not to take the chance.
Flush the roots by flooding the container until water is flowing out the weep holes. Do this a couple of times.
The plant might be in shock so wait a couple of days then find a spot in the sun.
Once the tree has recovered fertilize only once a month or every six weeks while in container and remember to reduce water as the weather cools next October/November.


The above followup was added by George on April 27, 2009 at 8:18 am PST.

Second George's advice

I second George's advice. And I find too, that young hard wood trees do not much fertilizer, especially when in a pot. You can flush the pot as George says, letting the water flow copiously out the weep holes at least a few times or more.

In fact when you water most plants, this practice it best done every time or at least once a month depending on soil and water hardness. When I water plants, I always water until water flows out the bottom weep holes. With major flushing, you let it go longer to wash out excess salts and nitrogen if you have just applied too much.

My experiences with Miracle Gro has not been good. I tried it some years ago, mixing at half the strength, and only watering less frequent then they stated and I burned the hardwood plants in pots left and right. I flush many times and saved most of them, but not all.

I thought I had found a new cool simple way to fertile a mass amount of potted plants with Miracle Gro and with no smell, but quickly switched back to my organic natural fertilizers with fish emulsion and composted manure bases. I started to use Lilly Miller natural Avocado/Citrus mix on most things and have great success and not burn, apply at the given rate or less.

I find potted plants should always be fertilized sparingly and mildly flush every time I water.

I find mango's need sun, but find they do well with no leaves affected negatively, under 50% light reduction polycarbonate sheeting, or under a patio roof, where they only get a few hours of direct sun. They just don't do as well, but the leaves always look ok.

I have found when the leaf tip and edges burn, or the leaves suddenly die for no seemingly good reason, look to the roots.

Which leaves have the white or bronzed edges, new or old or all of them?


The above followup was added by David Johnson, Waterford CA, zone 14 on April 27, 2009 at 9:23 am PST.

Reply to Second George's advice

Dear George and David,

thanks very much for your prompt responses. I find that the older(lower end of the tree) and some of the newer(few higher leaves) have the whiting or bronze color on edges. Apparently this tree is around 3-4 years of age and has 2 branches which have both flowered. Up until 2 weeks ago it was kept in a greenhouse and now is in a patio which sees 3-4 hours of direct light per day. Also the temperature in Fremont has been struggling to get above 64C for the last few days.


The above followup was added by Raj on April 27, 2009 at 9:56 am PST.

Leave it alone for a year

It will grow fine with 3 to 4 hours of direct sun. No more fertilizer for a year.

If the tree hasn't been damaged, it sucked up enough fertilizer for a year. They don't need much fertilizer anyway.

I over fertilized and fried a mango in direct sun against a hot wall. It probably would have died if I had left it there in the sun/heat.

I moved it into dappled shade for a year, no fertilizer and it recovered quite nicely.

The above followup was added by Tom on April 27, 2009 at 5:46 pm PST.

my glenn...

has been doing alot of nothing also. my other 3 mango trees (carrie, ice cream, lancetilla) are all flowering or budding.

The above followup was added by tammysf, san rafael, CA z9b/10a-sz15/16 on April 28, 2009 at 3:57 pm PST.

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