From my experience is, simply, if you flush now, then no fruit this year(next)

No guarantee that pruning will work but it would improve your chances.
good luck

If the tree starts flower buds in January, you may be in for a very late season. My lychee started blooming last November, so the timing was perfect for me. The crop was ripe in July.
Pruning is done after the crop has been harvested to get the timing right for the next season's flowers. I seriously doubt it'll promote flower growth at this point in the year. Has the tree experienced around 200 chill hours this year (below 50 degrees)?

North tree man - At this point it would not be regular pruning but simply removing the new growth hoping to delay it for another month. If it is flushing now there would be very little chance of flowers anyway, so he might consider it worth a try.
I have done this with limited success before in late October as just an experiment.

ronald and NTM: here is SoCal I think I only get 200-300 chill hours the entire winter. This year it has been unusually warm, and the temperature has been around 75F this month. So no, zero chill hours so far.

NTM, you live in a climate that is very different from mine. I wonder what is the usual time for Lychee to have flower buds in my zone. Has your Lychee started blooming this year?

I still don't know if I should prune it yet. Right now the flush is only in the form of buds.

thanks!

btw my lychee never flowered.

@ Ronald- I wasn't trying to shoot your suggestion down, but just elaborate on it a bit. I'm a little superstitious about pruning young lychees, especially when they are flushing growth.

@ Phase- The typical time of year for flower formation is between November and February...depending on climate/cultivar/etc. Clearly, it's November/December for me, and probably closer to February for you. My Emperor has started putting forth some vegetative growth, and I think, started some panicle spikes as well...time will tell though. I had to bring them in early this year due to premature frost warnings.

where I am in Jamaica , the earliest i have seen flowering is late November. Rarely as late as early January.

Of course 200 chill hours is unusual for us here, so I do practice girdling in alternate years. That would not be necessary for you guys so far north.

This will be a telling year for me. Both plants were outside until the last possible moment so they should have received plenty of chill. Both are starting flushes. Will just have to see how things pan out. Different climates, lighting.

Hey Jer, has yours recovered from the cold?

I am pretty excited about my Lychee's this year. The Sweetheart I have in ground has been growing great. My potted ones have not put on the type of growth the inground one has but they are all doing well and should get plenty of chill hours. It is supposed to be in the mid to upper 30's at night all week here. I just need one cluster of fruit from any of the tree's and I'll be happy.

Reading this thread brings up one doubt I have about my Lychee pruning. Between Aug/Sep, my Mauritius put out lots of new flushes. I pruned most of their new growth in Oct. I read that the pruning should have been done in July. On hindsight, I am wondering now if I should have instead pruned off the old branches instead? Now it's sending out a few more new flushes. So, I don't know if I have done something dumb by killing all the new growth that were supposed to produce fruit for next year? Any suggestions or comments as to what I should do next?

here in South Florida, ours usually bloom in late Jan or Feb.