I would try the sweetheart lychee variety. Be aware though, that Lychee fruit production is not optimal for SoCal. Having misters around the tree, would help out with the lack of humidity (this should make the Lychee tree happier).

Here is what I wrote in another thread:
I am completely obsessed with lychees and personally feel they can thrive here in SoCal. I believe that many people don't know the intricacies of growing lychees. Many people like myself go to a nursery and purchase a tree due to an impulse buy and slowly watch the tree decline and tell all their friends that Lychees are difficult.
Yes, our soil pH is a little high, our water is hard, the humidity is lower than Florida and the wind can severely damage the new leaves but there are easy ways around all of this.

I live in San Diego and got into tropical fruit trees only several years but my family comes from a Lychee growing district in China and when I went back to China about 10 years ago and ate some fresh lychees, I was hooked.

I am currently growing Sweetheart, Kwa Luk(Famous Hanging Green), two Kaimana trees, Ohia pink and Groff. My Sweetheart is the tree I've had the longest, I think its about 3-4 years old now and I got it as a toothpick. I've had it in a container the entire time and only planted it into the ground about 2 months ago. It is now about 4 feet tall and 6 feet wide. You can do a search for Sweetheart Lychee and I have pics of my tree from a couple years ago. It is about the same size because I had it in a pot the entire time and wanted it to stay small until I owned my own house.

After planting my Sweetheart into the ground, it seemed much happier and has lots of new growth buds popping out. To counter our alkaline soil, I incorporated lots of organic matter into the soil including lots of peat moss to make the soil more acidic. At first, I was watering my Lychee trees with Reverse Osmosis water but later switched to normal tap water because I got lazy and did't notice any difference in the health of my tree.

I don't feel humidity is much of an issue because my trees are healthy and my friend Phase001 whom also has a Sweetheart also has a healthy large tree that has fruited without any special added humidity.

Wind damage is the major factor contributing to the slow growth of my trees. The smaller the tree, the more dangerous the wind is. Think of each leaf as a solar cell that collects energy from the sun and converts it into carbohydrates it can use for growth of new leaves and branches or fruits. The smaller the tree, the fewer leaves it has. When a trees leaves gets too old, it will shed the old leaves and sprout new growth from the internodes. If the weather is extremely windy during new growth periods, the new leaves will be wrinkly, tattered, dried and may fall off. Because the tree is small, it has little stored energy for another flush. If you don't protect the next flush, the tree can die or become extremely stunted because the few older leaves it has is not efficient at photosynthesis and it just spent a lot of energy on new growth that got wind damaged and fell off.

Some important considerations when planting Lychees in SoCal are to incorporate lots of organic matter into your soil, innoculate the roots and rhizosphere with Mycorrhizal fungi/beneficial bacteria, innoculate with red/earthworms, use organic fertilizers and time the use of your fertilizers so you don't push too much vegetative growth late in the season. You want the tree to essentially run out of nitrogen well before the dormant period before winter. You also want to withhold water during the winter to depress vegetative growth and stimulate flowering.

If you want to see a nice looking Sweetheart Lychee tree that has fruited in San Diego, do a search for Home Grown Lychees. There, you will find pics of the extremely large, absolutely delicious Sweetheart that Phase001 grew in his backyard. We did have to hand pollinate the flowers although I'm sure the bees did a lot of pollinating too.

If growing in pots, I highly recommend using Smartpots or similar type air pruning containers although you will have to keep an eye for drying out of the soil.

None of my lychees have fruited as they are all small. My Sweetheart is the largest and has been in the ground for less than 1 year. I feel my Sweetheart will fruit within 2 years.

Phase recently updated his Sweetheart tree and he says he's got about 150 fruit.
Good luck and please keep us posted on how your Lychees do.
Simon

Simon,

Great post, I am growing 3 different Lychees. Goal is decent yields being achieved in SoCal. Sounds like the key is a rich moist organic soil, leaning toward the acidic side.

I have a Mauritius Lychee in a 18 gal SWC, using a good soil mix and mulched heavily with pine bark. It seems to be doing well in this environment.

Simon, great explaination. my tree is about 8' tall and 8' wide, but it was not cared for. when I started watering new leaves started to sprout for next season. I have about 20-30 lychees on it right now but they are very tiny ones (twice the size of a peanut) from last season and may not survive.

Yesterday I fertilized it with 16-9-12 NPK fertilizer that I got for roses. I need some growth and hope this will give it a jump start. Next step is that I am going to mulch it with organic matter today or tomorrow.

How do you water it? I got a 1/4" drip line to it with 4GPH dripper hooked up to my sprikler system that pumps water for 2-minutes two times a day. Daily, the tree is getting 0.25 gal/day or 1.9gal/week plus whatever the lawn sprinklers dump into the zone. not sure if its enough water.

Simon, how funny that you recently responded to my querry on lychee trees and today I stumbled across this old post of yours where you got Alphonso tree from Plantogram.com. Mickey is really a nice guy who picked up my phone at 9 PM. He sent me pictues of all trees that I was looking for.

Question for you. I am thinking about getting sweetheart lychee and Alphonso mango tree from him, but I was having trouble getting info from people here in So. Cal over their experience of Alphonso mango. Now that this post was year ago from you, you must have planted Alphonso and lychee and gotten some fruit as well. Could you please share some experiences and pictures? Thanks in advance.

http://forums.gardenweb.com/forums/load/tropicalfruits/msg0820213726468.html?24794

Hey behlgarden, sorry I didn't see your question until now. I did order my Alphonso mango from Plantogram and it is doing absolutely great. I tip pruned it heavily even though it was a small tree because I wanted good scaffold branches. I planted my Sweetheart Lychee and Alphonso mango into the ground last Spring and neither tree has produced any fruit for me yet. My Carrie and Nam Doc Mai produced a few small fruit last year but I plucked them off when they were nubbins in order to divert energy to vegetative growth.

Did you ever place the order with Plantogram?
Simon

Hi Simon, I did get Alphonso Mango, Sweetheart lychee, Sapodilla from Micky. Alphonso was almost 7 feet tall with sets of 3 branches ea in two spots. Lychee was a bit dork but I see a lot of new growth ready to explode. Sapodila is a real turtle and slow grower. I planted these 3 months ago and all survived so far. Lets see if we see any of them flower. I really enjoyed my longans that were size of a quarter but sweet and juicy.

Right now, enjoying mine 1.5lb Cherimoya and Atemoya's, really love these cherimoyas with great flavour and very very juicy. Also enjoying tonnes of guava right now.

Hey behlgarden, what varieties of Cherimoya, Atemoya and Guava do you have? As far as Cherimoya, I have Honeyhart, Dr. White, Dr. White seedling, Hybrid seedling, Selma seedling.

My uncle grows seedless guava and gave two for me to try and it was the best tasting guava I have ever eaten. Not a single seed in either fruit. He can give me a cutting but I'm looking to buy some larger rooted plants but can't find them down here. Ong's Nursery just sold out and won't get any more until Feb.
Simon

Hi Simon, the Cherimoya and Atemoya variety are unknown. I inherited this tropical garden/backyard from Asian women whose home I got in short sale that had 3 of these trees, 6 guava's (white and seeds are tough, but juicy fruits), one longan, one asian pear, and one asian apple tree.

I will harvest the cherimoya and Atemoya fruits and post pictures for ID,all three plants have different looking fruit and leaves.

I would love to graft my guava tree with seedless kinds. Keep looking at Home Depot as they are about to hit stores with bare root fruits of all kinds in Jan/Feb at very cheap price. THey currently are selling 8' tall 10 gal 5-in-one apple for $21, not bad at all.

I'm trying to find a lychee tree period. I cannot find any at all around my neighborhood! :( The closest thing I've got is an air layered longan of unknown variety.

Hey, I absolutely MUST have a lychee tree!!!!!! It will need to be potted since I live in an apartment.....and I can place a pot or so in the community courtyard.

Anyone in the San Diego currently air layering their lychee tree? Would you consider selling me one of your air layered propagations for $20 or less?

I lived in Asia for a few years (long time ago) and I miss so much about it, particularly the exotic fruits. In Hong Kong I had a lychee tree in the yard for a while. Was so nice.

A nice lychee tree would radically improve the quality of my life. Let me know if you would like to contribute to this excellent cause by sharing your lychee tree. THANKS!