I'm worried about buying a tree and finding it is impossible to dig a new hole due to the old roots. ==>>> ummm ... go dig a hole ... THEN GO BUY A PLANT ... just cut or ax out any dead roots ... or move your hole enough inches over ... to avoid any big roots .... starting the new hole about 3 feet away from the stump ... out to be about right ... personally.. i wouldn't go in the exact spot ... just too much work ... there is no rule.. you have to dig AFTER buying a plant ... ken ps: call miss dig about utilities if there is ANY chance of anything being under the ground ....

Try searching here http://edis.ifas.ufl.edu/TOPIC_Citrus_Pests_Diseases Here is a link that might be useful: Citrus Disease

Here are a few photos...and thanks for the comments already contributed! Here is the meyer. I'm not a roots expert but lots of the local citrus are grafted on trifoliate orange. It was in a pot for too long and had a really thick but short trunk when I planted it. It still has a low habit but has branched out quite a bit. The youngest leaves have a yellowish tint so perhaps it is suffering some. It's also starting some buds for flowers so it's clearly not been told we are just about to begin Feburary, not June :>) Meyer, General Habit Meyer, Leaves Meyer Buds Meyer Trunk Notice the wet-loving herbs such as wild strawberries and dollar weed Here are some photos of the wettest Ponderosa. It's seed-grown so it's on its own roots. General of several trees Ponderosa with crawfish burrows in foreground Closeup of mud Satsuma orange with crawfish burrows around it. This tree is doing great but is wet enough through the winter and spring for crawfish to make burrows in the same area. Here is a blood orange planted in a much drier location but it's a little over eight feet tall and hasn't fruited since I brought it from the nursery as a three-foot tree. Not sure if my wet soil is at fault for this one but it might be part of it. Many of you may rightly point out I'm letting grass compete with the citrus roots so that could be part of the blood orange's issue but I'm reluctant to use herbicides around my trees for a variety of reasons.

Could of have outgrown it's container or used up all the mix faster than the other? Might the others follow suit eventually? I'd check the soil and the containers and compare. Maybe that one got missed watering? Could be anything root related.