If you want them to fruit extensively I would plant both in the ground and be prepared to cover them if you get temps in the 20s. Both those trees can be kept at a manageable height so it shouldn't be too difficult. The lychee will take slightly colder temperatures than the mango.

My friends in N. FL do both. Some of them keep them in pots, and also have some in the ground, which they have to protect of course. So why not hedge your bet and do both? That's what I probably would do......

Also, if you do plant outside, probably best in the best protected (and warm) space you can find in your yard, or even up next to your house......

MDog

I live in FL zone 9b...two hours south of Orlando and get about 3-7 days of freeze depending on the year. I have both inground young mango and lychee trees and also a couple of potted ones.

I have had them severely damaged one year (not a single leaf survive) lost a couple of trees in 2010 (temps dipped in the low 20's) for a few mornings in row! Most of them survived due to covering with Frost cloth/blankets and a heat source underneath.

Lychee can take colder temps than mango but not until the tree matures a little at least 4-5 years old. The older and mature the tree gets the better the cold tolerance.

Here's a few pictures of the tree damaged in one of my winters...

Here's the tree 2 months later...April 2009

This is the same tree taken a few days go...you can plant them in the ground just be sure to add some heat source and cover the plant all the way down to the ground...think "green house" affect..

One of my winter protection...

Iam, have you decided whether you're going to leave your mango trees in the pot or plant them? Do you have pictures of your trees?