Kingsville Boxwood
 

I have attempted twice to grow Kingsville boxwood as bonsai. Each time
the plant seems to be thriving for about ~6 months and then suddenly
begins to die off, a section at a time. It turn brown and once it
begins to decline there is seemingly, no way to reverse the decline. I
have assumed it might be a fungal infection and treated the plants
with merit fungicide. There does not seem to any insect damage or root
damage.We are located a half block from the ocean, but others have
grown them successfully here. What's the solution short of giving it
up a loss cause?

Kingsville Boxwood
 

Kingsville Boxwood