My citrus trees need help

[harana]

I have 1-2 year old citrus trees that are in ground. They are about 2 to 3 feet tall. I have Satsuma and Kinnow mandarins, Clementine tangerines, eureka lemon, etc. I live in zone 9b in Sacramento California. Leaf’s are turning yellow, and are thinning out. I see no new growth or blooms. I cannot see any pests on them. I think they are in need of feeding. I gave them citrus fertilizer last year during summer and that’s it.
What kind of fertilizer I need to give them, how much and how often so they grow well?

[Bomand]

I am in zone 9. I start feeding 3 weeks before the first flush in Spring and I fertlize every two months till End of August. I do not fertilize again till Spring. During the summer I will spray or top dress with some micro nutrients......like fish emulsion or blood meal.   I use 13-13-13 as recommended by LSU ag center. 1/2 pound per year of tree age. This works well for me.

[Millet]

As Bomand wrote, your trees are greatly under fertilized. No nutrition in, equals no growth out.  During the first few years fertilizer is applied to young trees to stimulate vigorous growth of leaves and branches that become the framework of the mature tree. Beginning about 2 weeks after planting, frequent light applications of fertilizer should be made approximately every 6 weeks.  Avoid burning roots with high level nitrogen fertilizers applied all at once.  In your particular case, do not use a fertilizer with a  higher than 8-8-8 analysis, because your trees are to young . After your trees are 4 years of age and older a higher analysis fertilizers will be OK to apply.

[harana]

Thank you both for the response. As I mentioned my trees are small (age ~2 years and only 2-3 feet tall). For them how much fertilizer I should give every 6 weeks? Can I start this weekend or should I wait till March? Is top dressing of granular fertilizer is good? should I try to aerate the top surface around the tree trunk and work the fertilizer in it?

[Bomand]

Not necessary to work fertilize in. On ground application around the tree and limited to canopy shade. Micronutrients can be applied as a foilular spray, drench or dry on ground as done with bloodmeal. Watering in after fertilization is a way to get nutrients to the tree in a quicker manner.  You know when your fiirst flush is.....so 3 weeks before first flush is when my Spring fertilize program starts.

[SeaWalnut]

Buy chelated iron and spray the trees with it.

[harana]

Buy chelated iron and spray the trees with it.

I have "Ironite". Should I use that instead? If yes, how much per plant? Do it only once a year in spring or more?

If Ironite is not a good idea then how often and when I should spray liquid chelated iron?

[harana]

Not necessary to work fertilize in. On ground application around the tree and limited to canopy shade. Micronutrients can be applied as a foilular spray, drench or dry on ground as done with bloodmeal. Watering in after fertilization is a way to get nutrients to the tree in a quicker manner.  You know when your fiirst flush is.....so 3 weeks before first flush is when my Spring fertilize program starts.

Excellent information. Only one piece missing. How much to apply per plant?

[Bomand]

For granular fertilize I use 1/2 lb per year of age of tree. For macronutrients  depends upon how you are gonna apply it. For fish emulsion follow the mixing directions on the bottle. Spray in April and June. If using Epsome salt drench or dry bloodmeal also follow box recommendations. Different makers use different proportions.

[Millet]

If a tree is deficient in iron, then it is proper to apply iron in order to cure the deficiency.  Just as one should not give medicine to a patient that is not sick, one should not apply fertilizer if it is not needed. Supplying iron, or anything, if it is not required is not a good idea.  Harana's trees are 2 years old.  Therefore, the recommendation for a 2 year old citrus tree is 5-LBS. of actual nitrogen per year, applied over 5 applications. The amount of fertilizer applied per each application depends on the analysis of the fertilizer. If Harana purchases a bag of 8-8-8  the solution would be: divide pounds actual nitrogen required by the tree per year (5-lb.)  by % nitrogen of the fertilizer used.   For Harana's  two year old citrus tree   SOLUTION: 5/.08 = 6.2-lbs. divided by the 5 applications, or 1.2-lbs.per each application.

[lebmung]

I would recomand 660ppm N, 350ppm P, 250 ppm K weakly application for spring montha. Iron depending on formula it's always a good idea is to be used as drench than spray at 70ppm.

[harana]

Thank you for all the help provided. I love the calculations for dosage sizes.

How do I know if my citrus trees need iron? Their leaves are yellow or very light green. Is that the sign of shortage of iron?

[Millet]

Harana, the leaf symptom showing a deficiency of iron is:  NEW leaves with GREEN veins on otherwise yellow leaf.  NO wide green  border  around the vein.  NOTE: Iron deficiency often caused by high pH rather than shortage of actual mineral.