Question

Unhappy Tangerine   Hello Mike!

My boyfriend was given tangerine seeds from a gardener friend who assured him they would produce fruit-bearing trees.  He planted the seeds and grew small trees that stayed pot-bound for the past four years until I just recently planted them.  They were about two feet tall but have quickly started to grow taller and thicker in the month since they've been in the ground. There are six of them.

The soil here south of Houston is thick, dark clay. I used Miracle Grow potting soil and purchased bulk 'mixed soil' mulch/sand/manure from a local center and used both to fill a hole at least three times the size of the root ball.  

Since planting them, I've read that new mulch uses nitrogen to decompose. This mulch mixture is full of roughly chopped tree bark/sticks I realize it wasn't decomposed very much when I first used it.  The tangerine trees have some yellowing leaves and I wonder if that is due to a lack of nitrogen?  I've used some water soluble 30-10-10 once in a very diluted solution of 1 tsp per gallon about two weeks ago.  I used two gallons between all six trees and the day after we had an impressive rain storm where we received over four inches of rain.  Would that render the fertilizer ineffective?

Should I fertilize again? I've added a bit more Miracle Grow potting soil on top of the mulch surrounding each trunk in an effort to add to the soil but perhaps I need to dig them up and replant with less mulch? Or would that be more damaging to them at this point?    

You can see in the attached photo that some of the leaves are yellow and one leaf is turning brown. It is already in the 90's here so I am watering them about twice a week but wonder if the mulch holds too much moisture around the roots?  I would appreciate any advice you can offer. I've never grown any type of citrus trees before and don't want to damage my boyfriend's 'babies'. :)

Thanks!
Beth

Answer
Beth, the problem is most likely the hot weather. Trees should be transplanted in the fall or very early in the spring. In Texas, the best time is between October and March.  With the temperatures reaching the nineties, you do not want to dig up the plant and transplant again. That would sent the tree into shock.

You did the right thing using the fertile potting soil, but the mulch combination was meant to be spread lightly on the surface.  At this point, I would fertilize with a water-soluble fertilizer enriched with iron. This should help the greening process.  But too much care is sometimes the worst medicine.

The plant will eventually acclimate, but it will be stressed in the short term due to the heat.  Although it may not flourish this summer, it should recover nicely this fall.  Just be sure to provide 2" of water per week and fertilize every 45 days. By next year, it will need far less attention.

Good luck, and please write again if you ever need assistance.

Regards,

Mike