Lilly Miller is not considered a good fertilizer for citrus.

Many people think that Vigoro is good for in ground citrus.

As far as your condition, it sounds like a magnesium deficiency.

I would also recommend less frequent but deeper, longer watering.

Brief, frequent watering encourages shallow roots and a weaker plant.

Josh

I agree with Josh about the watering. However, citrus have a shallow root system by there very nature. 80 percent of a citrus trees root system is in the top 20 inches of soil.

Yikes, "3 minutes of watering every morning!"

Do you ever check the moisture content of the soil by putting a trowel in it?

The guideline for watering anything and everything is to moisten the entire root zone. I never watered my citrus more than once a week and they did famously.

Jean, who gardened in SoCal (Long Beach) for 30-some years.

Okay. First thing - is this little lemon tree getting sprinkled? If so, this is part of your issue. Citrus do not like to be in the path of sprinklers. They do much better with a deep watering via drip once or twice a week (depending upon how hot the temps get). If you're close to the beach, you probably will not have hot enough temps to water more than once a week. Lilly Miller citrus fertilizer is fine. It does contain micronutrients. Vigoro Citrus & Avocado fertilizer with micronutrients (that is the key for you) is also fine. Actually, the best NPK ratio is 5:1:3, but it's hard to find. As long as you've got a higher N (nitrogen) than P or K, as citrus are heavy nitrogen feeders, and you've got micronutrients included, you should be fine. Humic acid will also help, so look for that in your ingredients line up. I would recommend Grow More Citrus Growers Blend and mix it up as a foliar spray to help give your tree a good micronutrient feeding. Repeat in 3 weeks. Do your foliar spray in the evening. I would concur that you're probably looking at a micronutrient deficiency, possibly magnesium. Usually, you'll see a micronutrient deficiency with too much water and cold temps, so I would definitely check the roots of your lemon, to make sure it's not sitting in a puddle of water (i.e., in clay). Even though you're by the beach, you can still have pockets of clay. If you're in more sandy soil, then you're seeing an issue with both macro and micronutrients not staying in your soil, but washing out. If this is the case, then make a nice well around your tree out to the drip line. Fill with some worm castings and then top with compost. Keep both away from the trunk to prevent rot. Put your fertilizer in the well and water in deeply. Fertilize every 3 months and also I would recommend a foliar application with Citrus Growers Blend as well until your tree greens up.

Patty S.

Comparing pictures:

Yours:
{{gwi:608865}}

Magnesium def:

Iron def:

these pics are from here:
http://web.pau.edu/citrus_horticulture/Horticulture/Nutrition.htm

Here is a link that might be useful: Nutrition

Flower:

I have to agree that everyone here has given fantastic advice, especially about providing good watering habits and a great general fertilizer that provides all your trees need which most do.
I make sure I provide one that also has Calcium in it or use a product that does since most fertilizers lack this one nutrient.

The biggest thing I would be concerned about if I am going to invest time in good fertilizers is the pH. If your pH is not what satisfies your trees needs, not matter what kind of fertilizer you use, a pH of too high or too low is going to lock up any essential nutrients needed right in the ground, especially
Fe(Iron), Mn(Manganese), Cu(Copper), or Zn(Zinc), which is more tightly held in alkaline soils, another reason why they thrive in low pH (acid) soils.

Have you checked out the most important thing next to proper watering, the pH?

Good luck

Have a great day all

Mike