I've been growing for 24 of the last 27 years and all I've had to deal with were spider mites, bud rot, human varmints and a plague of scale insects that were introduced to my garden from a Madagascar palm that I threw under the grow light one winter.
The scale
I fought those little buggers for a couple of years. They'd cover the stems of my plants and it took me shutting down and restarting to get rid of them.
I've ordered and recieved clones over the years and have never contracted anything, but spider mites.
Knock on wood.