My guess is slugs or snails. When i see this i usually find one or two that have gotten past my defenses! I agree with Jean, it appears to have happened a while ago so hopefully the offenders have moved on.

It should be fine. Just be sure you keep it watered well while it is reseating itself. In your area, that means at least once a day. You could make sure you check the soil pH once it is settled in and add whatever it needs. I am sure you are aware that it needs a pH around 5-6. Your garden soil, which he may have used, could be above that, so just try not to be too upset. I had 25 clematis chopped down with a weedeater by a new gardener. It's life. Things happen. My DH sprayed Round Up on my roses and killed more than 200. Things happen. Life goes on. This post was edited by patricia43 on Fri, Jun 6, 14 at 13:31

Well, I see a few things that might be causing this. It looks like you've got a situation where you have a LOT of grass competing with both water and nutrients . You really do need to create a much large cleared area from underneath your little trees. Grass is a huge nitrogen hog. It will simply gobble up all that nice fertilizer you're putting down for your citrus. Not familiar with that particular fertilizer, but you'll want a fertilizer formulated for citrus, that is higher in nitrogen and also contains a good amount of micronutrients as well as your NPK macronutrients. And if your trees are being sprinkled by your lawn sprinklers, this is NOT good for the trees. This actually can eventually kill a small young tree. They don't like their trunks sprinkled. You'll want to put your trees on a drip system, and give them a long, deep drink one or twice a week (depending up on how hot it gets.) Doesn't look like sunburn, and yes, young citrus trees can get sunburned if you live in very hot, dry, sunny areas (like AZ, interior S. California). I agree with John's recommentations, fertilize at least 3 times a year - I fertilize 4 times a year - February through September/October. And, I use a foliar fertilizer especially if we've had a cold, wet winter and spring, which for me tends to make micronutrients unavailable since my soil is mostly DG. Grow More Citrus Growers Blend is a great product, and can be applied both to the roots or as a foliar spray. Spray in the evening. Patty S.

that first hole.. looks like hail damage ... there used to be a very active citrus forum ... if you wish to learn how to grow it better ... the yellowing bothers me ... but i dont know what that means.. in Oz ken