Interesting. Harry has muck soil, but while his other lychees look spectacular, the emperor always looks like it's struggling.
Brad, are you sure that you have high ph soil? The soil database shows a lot of sarasota with finely-grained, acid sand with ph numbers in the low 5's. Have you had a soil analysis done? Those ph meters and soil tests from home cheapo and lows are so ridiculously inaccurate as to be completely unusable. I eventually got a nice glass electrode ph meter and sent my soil off to a lab to compare.
Northern Broward and above seems to have neutral to acid soil. I had to import mine (for the new lot) from Delray Beach to get something decent. The ph on my imported soil is neutral, but before they dug it up, the top several inches were a ph of about 6. Unfortunately, the nice acid top portion got mixed with calcium carbonate from below, which raised the phs some, but I'm still happy with a final ph of right around 7.