Where do you live? How and how often do you fertilize? Do you know the pH of the soil and your water? Do you know the age and rootstock of your trees? A photo of the whole tree? All of these things help us to give you better advice.

I am in Phoenix, Arizona. I used light fertilizer at the beginning of Spring but only once. The soil and water are neutral ph (about 7 but I haven't checked in awhile). The tree is three years old, I think. I'm not sure. I planted it 6 months ago.

I posted a picture. I can take better pictures tomorrow if necessary. This picture was taken a few weeks ago.

Thanks,
Grant

You should be fertilizing at least 3 times per year during the growing season; get a good citrus fertilizer and apply it per label instructions at the drip line of the tree. In general your tree looks pretty good; perhaps a little leaf damage from CLM (?) or slugs/snails. I would clear away the grass around the tree; citrus are very poor competitors for food and water.

I don't think fertilizer or pH issues are causing the splitting. This is usually due to either the after effects of some freeze damage or, possibly the trunk is getting wet repeatedly, and you're seeing some foot rot going on. Get rid of all that grass, make sure your tree is not being hit by lawn sprinklers, and pull the mulch away from the trunk. Be sure the trunk is not the lowest part of the water well, but that a water well will cause the water to pool in a ring around the tree at the tree's drip line.

Patty S.

Forgot to address the split trunk. In Phoenix it could be due to sunburn; it would be wise to paint the trunk with white latex paint... the cheapest kind diluted 1:1 with water.