While you are awaiting an answer this might be a good time to give your tree a good root flushing to start the summer. I have flushed all my trees with gallons of water. Check out the PH of your soil.
This is the tree I flush then repotted it in more suitable container for outside. growing. Click on the picture to open my display. Use arrow keys to navigate.

{{gwi:31428}}
Seed grown meiwa kumquat tree.

Could you post pics of your tree. I like looking at pictures

Hi katsols,

I used 1/4 a cup on my blood orange that is potted in a 16" pot a couple weeks ago and it is doing okay. I think I should have used more though because some of the leaves are getting abit yellow on the tips. I think 1/2-1 cup should be fine for your tree. :-)

As you stated, the directions are for a soil grown tree, NOT one in a container. Using the same amount could kill your tree. I would call the toll free number on the packaging and ask for advice. They probably get that question all the time.

Just think about it.....do you think that the soil volume in your container is anywhere near that of a soil grown plant around the dripline? The dripline is also likely to be a few feet away from the trunk. The roots will be distributed far and wide in the soil. Can you equate your plant with all of that?

Hey guys sorry for late reply! i get home late from college and their offices are always closed when i call =\ and they haven't replied to my e-mail. I used half of a cup just to be safe i'll try calling them again perhaps from school.
Here is a pic of my tree.

5 years too late, but I had the same question and called - thought I would post what they told me just for anyone else who comes across this with the same question. Jobes' customer service told me to use 1.5 teaspoons per 4" round pot.

That confuses me. A 4 inch round pot of 4 inches deep holds a volume of dirt. An 8 inch round pot of 8 inches depth contains 8 times that volume of dirt but only get 2 times the feed. A large tree would starve to death under Jobes' guidelines.

Steve

EC the first mistake you have made is using an organic fertilizer in a container plant. It would be OK (but not the best) for an outdoor tree, but not for a container tree, A container tree does not have the microorganisms to make an organic fertilizer available to the tree.

Hmm... what would be better? I haven't used it yet, but I've been looking for something because my year-old lemon trees have started yellowing a bit. I moved them into larger pots (the 6" pots from 4" pots), and hoping that repotting helps. I haven't figured out what the best system to fertilize is though. So far, I haven't been using any.

Easy and off the shelf Miracle grow 24-8-16

It is over priced here but you can find it elsewhere for less

Steve

Actually both of the above fertilizers (24-8-18 and 9-3-6) pretty much offer the same NPK ratio of 3-1-2. A person would just use more of one and less of the other. The 24-8-18 would probably be less expensive to use;.

But the MG does not offer the same range of micros as the Foliage Pro does. And the Jobes is missing them entirely (in addition to be a granular organic, so not very efficient in a container growing situation).

gardengal, I can find a lot of information concerning Miracle Grow 24-8-16 but not the 24-8-18 formulation poncirusguy suggested. From your post evidently you must know what range of micros MG 24-8-18 offers, I curious to know, what are they?

That must have been a typo on the part of poncirusguy.....there is no MG 24-8-18. It IS 24-8-16 and that's what I was referring to.

24-8-16 I corrected my post above

Quite a few fertilizers are sold without Mg. One can just use Epsom salts as needed.

MG 24-8-16 lacks calcium. Egg shells soaked in vinegar works.