Duncan Mango Grow Guide

Duncan is what we call a “Triple Threat” Mango because it has:

  • Excellent Disease Resistance
  • Amazing Fruit Production
  • Low-to-Moderate Growth Vigor

Honestly, it’s pretty rare to find a mango cultivar that checks all three of those boxes! ☑️☑️☑️

With that being said, this grow guide will cover everything that you need to know about Duncan Mango:

Table of Contents

Duncan Mango Tree Growth Habit & Fruit Production

The Duncan Mango is considered a small to medium-sized mango tree. However, if Duncan is not properly pruned every year, they will naturally grow into a much larger tree.

Duncan Mangos have a low vigor & spreading growth habit that produces an open canopy. As a result, Duncan can realistically be kept between 8 – 15 feet tall with annual pruning. Despite the tree being easy to manage, Duncan’s lack of natural compactness means that it would not do well long-term in containers and would not be considered a “condo” mango.

Duncan is highly precocious and will begin consistently producing good to heavy crops early in its life. This is partly due to the tree’s tendency to produce large clusters of fruit throughout the tree, a trait inherited from its father, the Carabao (Philippine) Mango.

The mangos themselves are medium-sized fruits that typically weigh between 1 – 1.5 lbs.

Duncan Mango Flavor Profile

Duncan Mangos are considered an Indochinese Flavored Mango.

Slicing into the fruit will a reveal a beautiful orangish-yellow fiberless flesh that has a smooth, creamy & melting texture that is similar to Nam Doc Mai and is accompanied by a mild mango aroma with hints of apricot.

From a flavor perspective, Duncan Mango has a unique blend of indochinese & classic flavors. This translates to a mildly sweet fruit with the ever-so-slightest complexity that one would expect of an indochinese mango but with a clear classic mango flavor. Additionally, one can expect subtle hints of both tartness & tangerine-like citrus. When eating near the skin, there is a rather prominent bitterness that is very reminiscent of Carabao.

Overall, Duncan has a very “refreshing” flavor that is quite enjoyable. Relative to other mango cultivars that I have sampled, Duncan tastes like a milder version of Edward with the texture of Nam Doc Mai.

There’s honestly nothing not to like about Duncan 😄

Finally, it’s worth noting that Duncan Mangos produce monoembryonic seeds, which means that planting a seed from a Duncan Mango won’t yield another Duncan Mango Tree.

Duncan Mango Season (And When To Pick)

Duncan Mangos are considered a mid-to-late season mango (June – Aug).

Similar to other mango varieties with extended seasons, the earlier season fruit is usually inferior in taste to the later season fruit. As a result, Duncan Mangos that are picked in July/August are usually much sweeter and are much more likely to have the delicious classic & indochinese flavor combo that they are known for.

With that being said, the best time to pick Duncan Mangos are when they are mature and beginning to ripen on the tree. From a color perspective, this is when the fruit’s nose (bottom) is beginning to show signs of yellow color break and/or when there yellow stripes going from the bottom of the fruit to the top of the fruit. The presence of these yellow stripes are a sure fire way to know that the fruit is ready to be picked.

Duncan is perfectly ripe when the majority of the fruit transitions to a canary yellow color. However, it should be noted that sun exposure can make the top of the fruit yellow. This doesn’t necessarily mean that the fruit is ripe, therefore we should only focus on the bottom of the fruit turning yellow. While the fruit itself lacks a blush, they are nevertheless a very clean-looking mango due to their excellent disease resistance.

Aside from color, here are some additional tips to knowing when Duncan Mango is ready to pick:

  • Fruit fullness & shape 
  • How does the stem look? It’s it drying up near where it connects to the fruit?
  • Is the fruit’s skin beginning to stretch?
  • Is the fruit beginning to soften ever so slightly?

Additionally, while the fruit can be left to completely ripen on the tree, it should be noted that they will drop soon afterwards and can become easily bruised.

By the same token, I really like that Duncan is a very forgiving fruit. In other words, even if the fruit are picked a tad early, they will have an excellent shelf life and don’t tend to quickly develop any weird off-flavors.

Duncan Mango Disease Resistance

Duncan Mango is highly resistant to most mango diseases. This is a major selling point because there are not many mango cultivars that come even close to the level of disease resistance that Duncan has 😄

Duncan Mango History

Duncan Mango was first propagated in West Palm Beach, Florida by David Sturrock. The fruit was named in honor of Ralph Duncan, who had supplied Sturrock with maps for a book that he was writing. Fun Fact: Duncan is one of the few mangos that have ever been patented.

The original Duncan Mango Tree is still alive and located at Tropical Acres Farms.

Duncan is a seedling of Edward Mango. It’s pollinating parent is Carabao Mango.

Due to the fruit’s Edward parentage, Duncan is a sibling to Coconut CreamSugarloafAngieHarvest Moon, Seacrest, and Young. Duncan’s aunt and uncles include CogshallValencia PrideKent, Glenn, Bailey’s Marvel, Florigon, Cushman, and Van Dyke. Finally, Haden and Carabao are the grandparents to Duncan 😃

Duncan Mango Tree For Sale

Duncan Mango is a very common mango cultivar to source. When visiting my local nurseries, I almost always see Duncan for sale! I suspect this is because of Duncan’s amazing disease resistance, prolific production and favorable growth habit.

With that being said, if you are unable to find one at a local nursery, your next best option is checking out Tropical Acres Farms (not sponsored). They are the only legit place online (from my experience) that you are getting exactly what you are paying for. 

They have over 300 varieties of mangos available. You can either order budwood to graft yourself or submit a grafting request to have a grafted tree created for you. They do ship!

Conclusion

If you found this grow guide helpful, please consider sharing. It helps support the website 🙂

If you have any questions regarding anything mentioned in this grow guide, please comment them below! This way, others can also benefit from the answer to the same question. For any other questions or growing tips that you think may be helpful, feel free to use the contact form and drop me a line.

Thank you for reading! 🙂

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Matthew Rowlings

I have an Associates Degree in Biology from the University of Florida and am also an active Florida Master Gardener. I am located in Central Florida (Zone 10A) and have 6+ years of experience with growing 20+ types of tropical trees. You can learn more about me and why I started Tropical Tree Guide on my about page.

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