Nutricote or Floridian is the best. I have had best results with the triple 13 and triple 14 with minors.
Your mix should work just as well. The longer release time means you can add more without burn. Summer hot temps means 270 days is more like 120 day during summer. I swear by nutricote nothing else is even close for me except maybe liquid nutrition but that is a lot of work. eBay has 50lb bag nutricote triple 14 for $135 delivered and has perfect blend with sulfur  and minors.

Is there a possibility that some of the root stocks vary, similar to the behavior or vigor of the tree above ground? I know some of my Fla root stocks can fill a pot with roots in no time, and others grow very slow. I would expect that Manila root stock to have similar variability. There are so many variables I guess, that I find it hard to determine definitively. I am always open to other's experiences and would love to find the magic bullet that solves all problems. Perhaps the manila would be better, just not sure.  I wish the Fla varieties were more readily available on different root stock such as Manila. I have a difficult time getting a graft to take in such harsh dry weather.

Behl please share with us the evidence you have that turpentine root stock will not do well in Ca.
There are so many contributing factors that could be reason for decline so I am curious what evidence you have that pinpoints the problems to definitively prove it's the root stock and not just a plug for a way to sell your own trees. I think some growers on this forum from Palm springs have no issues with turpentine in desert clay soil. From my experience the biggest factors contributing to mango decline are:
1. Planting the tree too deep in the soil. Mango trees like the feeder roots to be able to breathe and dry out frequently. Over the years I have learned this from noticing shortly after adding additional soil and mulch that they start to die back and decline. Once removing what was added the decline stops.
2. Over watering. They definitely start declining after too much water.
3. Over fertilizing and too salty of fertilizer. If you use the wrong fertilizer or too much fertilizer the roots become damaged and struggle to supply water to the tree.
4. High PH soil. If you do not correct the soil PH the tree will have troubles thriving and always show nutrient deficiencies.

I have found that if you foliar feed on a regular schedule the trees thrive and never have nutrient deficiencies.  For the most part I have all but stopped adding fertilizer to the soil and solely foliar feed for the trees nutrient needs. They almost always are putting out new growth and salt is no longer a problem.
Dyna-grow Foliage Pro is what I use and contains very little salt. When it rains the roots get fed with the runoff from the leaves. This is enough for the roots and prevents root damage from salts. When I water I water slowly over a fairly long time, and then leave to dry out. Once the tree shows signs of drought stress then it's time to drip water again.
I have both Manila from big box store here in Phoenix, and Fla mango trees and they both act about the same in the poor soil. The manila may have more vigor than some of my Fla varieties, but some Fla varieties like Peach cobbler grow like crazy.
Really curious how you have concluded it's the rootstock and not the care, poor water quality, or variety specific.
Also one thing to keep in mind is some varieties do well outside their normal climate, and some do not. For instance, most Asian varieties do not grow very fast in dry climate. Has nothing to do with the soil. I have both in ground and in pot. No difference in growth rates..nothing to do with root stock.

Quote from: mangomaniac2 on April 04, 2016, 02:17:58 PM

The years you save by going with 7's and 15's goes a long way in your enjoyment of your new additions.

Not really, you will usually wind up with a better tree when you raise it and control/determine its shape from the getgo.  Nurseries usually do very little to enhance a tree's growth or shape, all they do is keep them in pots and try to maintain an adequate water and fertilizer supply as economically sufficient as possible.

Quote from: mangomaniac2 on April 04, 2016, 02:17:58 PM

The yard always looks a lot better with a nice full tree in the ground and much more fun to watch grow.

Again, disagree 100%, and as most in this thread have stated, planting that 3 gal and having the owner (not the nursery) raise it and manipulate its shape will almost always provide for a healthier and overall better productive tree in the short to mid term (3-5 years) and beyond.  I guess the question is, what are you after, a possible 5 or so fruit next year (a sprint) or potentially 100 or so fruit in 3.5-5 years (a marathon)?

You would think the  buyer will pick a nice looking tree and not a rag. The buyer can shape the tree whether larger or smaller on their own over time, and will eventually have to trim anyways.  The only benefit I see for a 3 gal is price, and for a nursery, profits. If you can talk people into thinking 3 gal is the way to go you are more profitable by going from graft to ground sooner. Nursery can keep more stock of 3 gal and increase sales. Why not try talking people into a one gallon pot? Imagine how much more proud a grower can be and the roots can really establish themselves early....CMON ...people buy fruit trees to get fruit. Some examples you may have of more success with 3 gal is no guarantee, every specimen is different within same or different varieties. What you can guarantee is that if you start out larger your chances of survival goes up dramatically, and time to fruit goes down significantly.  Nothing sucks worse than buying a little 3 gal tree and finding out the specimen you have happens to be slow growing. To Rob's point I have had a couple 3 gal trees take off and in 1 year more than triple in size and amount of branching, but that is more rarity than is the norm. The amount of water, fertilizer, time savings is always worth paying a few bucks more for larger more established tree.

Quote from: zands on April 04, 2016, 01:05:21 PM

#1---  I would get one more tree to make four in all. One from the poly-embryonic side like Nam Doc Mai/NDM
#3---  I would get at least one of your "dream" mangoes in 15 gallon so you get fruits sooner.
#4-- You could get one mango tree each in 3 gallon/7 gallon/15 gallon or otherwise diversify, Say two 3 gallons and one 15 gallon

Good advice, we do have a 3G nam doc already in our yard. It's on the small side. Stared as a 3G. We are thinking of 2 at 15g as they look good, healthy and ready to be planted, while one variety looks better in 7g.

You will be happy you got the nice bigger ones when you are picking fruit in the near future.  Great idea to let the specimen determine which size to go with. You are right sometimes the 15's can look worse than than a good 7. I let the nursery do the waiting game with the small stuff. The years you save by going with 7's and 15's goes a long way in your enjoyment of your new additions. The yard always looks a lot better with a nice full tree in the ground and much more fun to watch grow.

I'm in northern area of south Florida. I'm going to be adding a few mango trees. Trying for an extended fruit supply in the future, with an early, mid, and late season varieties. Southern Blush, Carrie, and Kent are what we're looking at. Have lots of size options to purchase here from 3 to 7 to 15 gallon sixes available. Will I get fruit production from 7 or 15 gallon sizes next year? What are the pros and cons of planting the different sizes other than cost to purchase?

Go with the largest you can afford to plant. You will be happy you did because they are much easier to care for the older they are, and you can get a descent amount of fruit from a 15 gal tree if you get a nice sized one. Southern blush is really awesome, my wife's favorite. One thing to keep in mind is that many of the newer varieties are much more disease resistant. A lot of the older varieties tend to be more prone to fungus and disease. As the others have suggested you may want to wait until you can get a good sample of some newer varieties first before making the commitment. A lot of the newer varieties have a lot more flavor than the older ones as well. Carrie and Kent are easily beat by many newer varieties, Southern blush not so easy to beat and is pretty easy to care for. Pickering is one tree everyone should have. Super productive, easy to care for, dwarf, and great tropical flavor. Lemon Zest, Maha Chanok, Sweet Tart, Peach cobbler, and dupuis are very tough to beat with excellent disease resistance.

Growing Mango in pot, in cold climate is hardier than other species....i lost 3 Mangos during winter.
I agree, the overwatering could be the main problem....as i notice, with low temperature, they resist to dry, but die if the soil is too wet.

This is why you need light airy soil. Then the soil does not stay wet so long. Couple that with spraying Organicide fungicide bi-weekly to monthly and it's piece of cake once you know what to do.

Thank you for the info. I'll definitely buy more. It's a hard lesson learned but I think Im going to follow Al's gritty mix. This seems fool proof.

Dude, al's mix is a heavy heavy soil. Stays wet all the time. You do not have the weather for that. Al's mix is ok but not all it's cracked up to be. Al's mix is for bonzai trees that grow very little but stay healthy. I started with that for the first year and ended up changing all the soils out because it made the pots too heavy to move, stayed wet too long during winter, and did not hold any organic material which mango trees really like.  I am providing you valuable info so that you do not end up wasting more of your money based on all my learning experiences and losses I had over the first couple years. Again you need LIGHT soil, not heavy rocky soil. You need something that dries quickly, not soil that stays wet forever.

I am having some serious bad luck. 2 of my Potted mango trees have died, and now my icecream mango tree is showing the same symptoms as the last 2 before there demise. I cut off the sick infected areas 3" past. I don't know what do do please help me. I also sprayed copper last week, still nothing. Please help me ID this disease, and help me save my trees.

Being in denver and often indoors you will need quick drying soil. You may need to start with new trees as it is really hard to turn your problem around once they decline. Use a soil mix of coco choir, perlite, pine bark or sawdust, and compost. I would say 35% coco 15% sawdust or fine bark chips, 35% compost, and 15% perlite. Since mango like 80 to 90 degree temps you should keep in a greenhouse most of the time to reach those temps as I doubt you keep your house that warm. 70 or 75 degrees is cold to mango trees, fine for winter but not during the growing season. Make sure to water slowly for hours and then let dry out really well before next watering.  Without a greenhouse in denver I am afraid you are wasting yourtime and money.

Simon,
The Manilla is too slow of grower and turpentine is much more vigorous. During all the heat waves that hit, and much of So Cal is desert like, you want the more vigorous rootstock. For me, I would rather have a more vigorous tree of certain variety than one that does nothing much of the year. Here in AZ Lowes has stopped selling those high graft manilla rootstock varieties and only sell the seedlings, because most of the varieties barely grow and are an eye sore to look at with the high graft.

There is a nursery here in Phoenix that has 30 to 40 of them, too many to count. There were 3 long rows of them and I was able to pick the one with the most branching.

All mango varieties are similar in cold hardiness..some trees can fare better than others but is not variety specific.  Key to mango during winter is frost protection below 38 deg farenheit and make sure to stay above 25 deg farenheit.  Water well during cold spells and make sure tree has plenty of nutrients including silica before cold arrives. Very simple really..they are pretty hardy. Fungicide application during winter is critical..I recommend alternating organocide plant doctor and liqui-cop every two weeks when temps reach 55 deg farenheit or lower.

I would seriously question that his Fruit Punch mango is the real thing.  Just met with someone from Ft. Myers who said someone is selling bogus Fruit Punch fruit.  How do i onow its bogus, i showed this person a fruit and let him taste it qnd he said what is being sold in Ft. Myers was shaped different,  smaller in size and tasted different...a dead give away.

How do you know the individual wasn't just confused or forgetful? You are speculating that nobody in Ft Myers could have a fruit punch for sale. That's not accurate whatsoever.