Lemon Tree wrinkled leaves
I'm in Bangkok Thailand and planted three lemon trees from some sunkist lemons I bought at the market. I think they are just over a year old now. Some trees are doing better than others, but all of them tend to have some leaves with wrinkling.
I've never fertilized them; just dug a whole in the ground and threw a few bags of potting soil in and let them grow.
I'm wondering if they need fertilized or this might be some type of disease? Any help would be much appreciated.