Upping the difficulty here. Vegas desert.
Unlike avocados, mangoes have been proven to be able to fruit here. It's just really, really rare because barely anyone knows how to grow them in soil, humidity, and weather like ours. High pH, clay soil with rocks and awful drainage. Super hard water. Hot as hell in the summer more often than not. Temps get perilously close to, or occasionally a little under freezing. Every 7 or 8 years we'll get just enough snow to make life miserable for plants.
I have some polyembryonic seeds I started of Lemon Zest, Lemon Meringue, and Coco Cream and my experiment is to grow the cloned shoots without grafting so they have a better chance at being vigorous and more tolerant of our conditions.
Two questions:
When digging the hole, should I mostly stick to native soil? And if so, should I amend it with some organic matter at all, or other things like sand/sulfur? Or just leave it as is and top dress with sulfur and iron sulfate?
My understanding is that even if mangoes hate our dirt, digging a hole and putting good stuff it likes in there will just cause the roots to gird around where that good soil is, and also very negatively affect drainage.
Also, any good sources for manila seeds in case I want to use that as a rootstock later on?
I am not an expert at all, just want to share my own experience.
Native soil is way to go, but if you have clay muddy soil, I will use cactus/palm soil mix to fill up the hole. Mixing the native soil with sand could work, but my trees seem happier with cactus/palm soil mix from home depot. I usually do some prep first. Dig the hole about a week in prior and make sure to loosen up some soil around it so the hole has a good drainage. I've killed some mangoes because the clay soil around the hole was too dense.
Make sure that when you put the mango tree, it is higher than the ground level around it. Some varieties cannot stand wet feet at all. My Son Pari and Dwarf Hawaiian died just after one full day of rain in the winter.
You are smart by starting from seeds. Even Manila rootstocks cannot beat seed growing mango trees in my yard.
My yard received about 12 hours of direct sun in summer, and very dry heat with occassional Santa Ana wind.
I have about 8 mango seedlings from different varieties, and it all grow well. My Coconut Cream on Manila is actually struggling a little.
Some varieties are just a strong grower no matter what rootstock they are on. These are very strong grower on turpentine rootstock in my yard (i don't do much care on my trees):
- Orange Sherbet --> it grew 4 ft in height and 5 ft in width in 2 short years. Very drought tolerant.
- CAC ---> it only grow 2 ft in height but about 6-7 ft width in 2 years from a little stick in 3 gallon pot.
- Super Alphonso --> I just bought the grafted tree about 3 months ago, and it was only 2 ft without any branch. Now it is about 5 ft with 8 branches, I never even tip off the top.
- PPK --> this tree just want to grow and make new branches, it does not even bother to flower. Same, grew about 3 ft height and width in 2 years.
Varieties that didn't survive in my yard on turpentine rootstocks (they all died in winter after rainy days):
- Venus
- Peach Cobbler
- Son Pari
- Dwarf Hawaiian
- Little Gem
- Triple Sec
Just a little to add, Manila grown from seeds are also very variable. Some of my Manila rootstocks are strong, some are just weak.
I hope I can help just a litle bit. There are many very experienced mango growers here, and I learn from them.