Help! My young nansho dai dai has stayed yellow despite fertilizing with miracle grow like all my other young citrus. I gave it some ironite this past week. Will that help? I have four other citrus planted in same area and they are green as grass. The nansho did grow this year though. Any thoughts?

Nitrogen? all the rain we've had lately may have washed some of the fertilizer away. Post a picture.

Glad you have had rain... We haven't had hardly anything all summer down here on the coast.

I've had lots of rain too. I thought nitrogen deficiency too, and also fertilized with blood meal two weeks ago. Wired thing is the other trees in same bed are all dark green. I can't figure out how to post pic. Just tried to join imageshack skypath and can't. Some leaves all yellow and falling off and some are yellowish with green veins.

What type of soil did you use when it was placed in its original container? Did it have yellow leaves prior to it going into the ground?

It was yellowish when I got it in mail last fall from Woodlanders, planted in miracle grow potting soil in bigger pot and it greened up put on size over winter in house like the other three trees I ordered. I planted them all outside this spring in same bed/area in amended black soil on slope with good drainage.

I was wondering if your plants were on different rootstocks. You mentioned that your C. taiwanica is from Woodlanders so I assume that means it's a seedling on it's own roots. C. taiwanica is used as a rootstock, but I don't know what it's preference is for soil conditions such as prefered pH range. Maybe someone else knows if that might be a factor?

After fertilizing with ironite a week ago the tree is still yellow. I've noticed the mulch under it is greenish like algae growing on it. Does that mean too much nitrogen? I'm thinking about digging it up and potting it; maybe root rot. Would go into winter too weak to survive anyway, so if I pot it I can bring it inside and might perk up. ???

It could be a dozen things. Without a good picture it is only a guess what the tree's problem is. With a good picture it should not be very difficult to provide an answer. Adding this and adding that, in hopes of finding a solution, normally causes more problems. - Millet

I just put pics on imageshack and will try to post here:https://www.imageshack.com/i/05jpe8j
Lets try another one:

As Ryan wrote, it certainly looks to be a nitrogen deficiency. Note that nitrogen deficiency shows up on the tree's older leaves, while the newer leaves will still have some green coloration. Nitrogen is VERY water soluble, and can be quickly leached in fast draining soils from the root zone by frequent rains, or by excessive hand watering. Applying a fertilizer with a higher level of nitrogen should clear the problem up. At this point I would not recommend using an organic type of fertilizer, they are much to slow acting for this situation. - Millet

Thanks, Milet!

Just an update: I dug up the Nansho dai dai and potted it and fertilized with osmacoat over a month ago, and it is in dining room now all green and putting out new growth; put outside somewhere else in May.