Hi Pokerguard. The symptoms shown on your tree's leaves are not iron defiency so don't apply any more Ironite. Instead, save this product for your lawns. Lack of iron produces yellowing of the leaf tissue in between the veins, which stay green - this is called chlorosis. The damage to your trees leaves almost look like salt burn or even sunburn.

How do you water this tree? To prevent salt burn be sure you are watering to a depth of three feet each time you apply water. For citus water once evey 10 day to two weeks in the summer tapering to once a month in the winter. It's hard to say how big your tree is from the photo but a citrus that has a canopy diameter of 8 feet will need about 70 gallons of water each time you apply it. A tree with a 5 foot diameter canopy will need about 30 gallons each time, while a tree with a 15 foot canopy will need 250 gallons.

Citrus like to be watered deeply but infrequently. Soils that are too moist can actually prevent the uptake of nutrients, like iron and nitrogen.

The best way to apply water for citrus is to construct a basin under the tree with a 6 inch earthen berm mound at the drip line (edge of canopy). Fill it with water and allow it to soak in. If the moisture isn't soaking down to three feet, fill it again.

You don't say what part of Arizona you live in. The damage to your leaves could be caused from frost/freeze. It could also be caused from lawn sprinklers hitting the leaves. The water drops could freeze or also act like mini magnifying glasses in the sun and could be burning the leaves.

Be sure not to overfertilize your citrus. The best way to apply nutrients is to use the holidays of Valentine's Day, Memorial Day and Labor Day to help remember. Apply 1/3 the annual requirement on these days by spreading it evenly over the rootzone of the tree and watering in well. Don't use fertilizer spikes as these tend to concentrate the fertilizer in one spot which can cause salt burn.

Don't be too concerned if your tree produces flowers occasionally throughout the year - lemons often do this. The most heavy flowering will occur in March.

I hope this helps.

Here is a link that might be useful: Information on citrus

I'm in Phoenix in AZ... Southern to be exact. The tree is about 8' tall, and the drip line is about 6' in diameter.. it's a dwarf lemon tree.

Thanks for the information and link. It does appear that it's salt, but there is nothing that hits the leaves, so it must be in the soil.

The tree is on a drip irrigation system, and only has 1 dripper, 2gal/hr... and over the summer, I've been running it daily for 11 minutes a day... too shallow and not enough water. I have this tree, an orange, 2 Queen Palms, and 2 Mexican palms all on the same line.

I'll turn off the irrigation for this tree, and give it a bunch of water (10 gal or so) to try and leach out the salt over the next 2 weeks and see how that goes.

Thanks for the information.

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Thanks for the photo. It looks like your tree was only getting a little more than 1/3 gallon of water each time the system ran during the summer. No wonder the leaves were showing signs of stress.

To deliver enough water you will need to run your drip system for 15 hours which is impractible. Instead, add two or three more 2-gph emitters so you'll only need to water for 3 hours or so. Use spaghetti line and in-line connectors and place the emitters between the drip line and the trunk. This will also be good for your other trees as well.

Good luck.

Here is a link that might be useful: Citrus Fertilization