Banana plant yellow leaves

Heya, we recently transported a banana plant / tree to our garden, in the last week all the lower leaves have gone yellow and it doesn't look happy.  The earth is a mix of aged manure, local soil and substrate.  I don't suppose anyone knows if this is a typical transplant shock issue or something I need to deal with?  I'd imagine there's a good amount of nitrogen in the soil, but with the weather it could be over watering?  I've reduced the water timer to compensate in case that helps, but otherwise I have no idea!  Any help would be greatly appreciated!!!!!