Kaffir lime - help

9 years ago

I joined the forum coz I need some help with my kaffir lime trees. I have several trees and they are about 3-4 years old and I live in South West Virginia. Trees live in 5gallon containers. My potting mix is made up of a high quality potting mix (happy frog, I think it's called), plenty of perlite, a soil conditioner and a handful of orchid bark. I think I've got the mix right as the drainage seems good and the trees are growing and the soil is drying out and not remaining moist. I fed them a cup of citrus fertilizer a month ago, and every two weeks I spray them with a compost tea/ sea weed fertilizer. In addition, once a week ill spray neem oil to prevent spider mites, powdery mildew and scale.

The trees are growing quite well considering we had a cold winter and spring was late to arrive. I have plenty of new leaves and the trees blossomed and bear fruit. I pinched most of the fruit though as I want the trees to become stronger. I keep them in a high tunnel during the winter and only now am I gradually bringing them outside on the warmer days and putting them back inside when it cools down.

The problem I have is, the vein running through lots of the leaves is turning yellow. When I see a leaf with a yellow vein I know that if I pull on it slightly it breaks off the tree. These leaves are brittle. The yellowing in the vein then spreads through the smaller veins. It's very frustrating. Here are my thoughts:

Am I over/under feeding the trees?
Was a cup of citrus fertilizer to little for a 3-4foot tree. I'm also spraying every two weeks with seaweed fertilizer, maybe this is too much?

Too much / too little watering?
I water when my moisture meter reads less than 3 (on a scale to 10), top few inches of soil is dry and when the container is light to pick up.

Is this the tree taking nutrients from these leaves to give to new growth?

Possible a nutrient deficiency? Magnesium, zinc etc......

Maybe my soil ph is out?
I've never checked what it is. I always use collected rainwater for watering and spraying.

Maybe the lack of steady temps and some consecutive sunny days. .

It might be that once I get them outside full time they will heal themselves and I'm worried about nothing. Is just very disconcerting to see so many leaves with a yellow vein and popping off the tree. If anybody has any advice, I would greatly welcome it, since I've put so much time into caring for these trees.

Comments (7)

wayne-g-j
Original Author
9 years ago
A picture of one of the leaves with a yellow vein and slight yellow "hallo" along side it.
nikthegreek
9 years ago
I see nothing very wrong in this particular pic. If you see strong yellow veining all over the leaves, this is usually the sign of nitrogen deficiency and/or leaf senesance but it can be the sign of bacterial or viral disease. I am willing to bet that your particular case is senesance from shock stemming from unstable temp and/or light conditions.
Nik
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johnmerr
9 years ago
Too much, too often neem oil will slow the growth rate, as it restricts the respiration of the plant. Neem oil is not preventative; it should only be used when you have a problem that needs to be addressed.
wayne-g-j
Original Author
9 years ago
Ok, thanks guys.

I was hoping it was something like unstable temps / lighting conditions and will rectify once I get them outside full time. My high tunnel is home made and I've always used 6mm plastic from Home Depot. Do you think I should invest in some proper green house plastic? Everything I place in the tunnel grows but I wonder how much better they would do with the right type of plastic.

Anyway, I gave them a little extra fertilizer just in case and I'll ease off the neem oil. I use the neem oil coz we have bad powdery mildew in our area, plus it seems to help with the ants that bring scale. I guess I need to be patient and see how things develop.

Thanks agin
W
nikthegreek
9 years ago
Do citrus get PM in your area? I've never seen citrus getting PM over here and I live in the PM planet in spring and fall as can be testified by my roses, my grapevines and other plants.
Nik
wayne-g-j
Original Author
9 years ago
Hey Nik

I think its PM. It's like a dust that settles over the leaves. It might be sooty mildew or something else though. The first year I had my trees, I just thought it was dust and then I realized it wasn't. I can wipe it off quite easily but I use the neem oil to keep down the insects that spread it and also scale. In virginia it is very humid and when the trees are in the high tunnel, air flow is restricted despite having a fan blowing etc.... If I relax my guard, then scale and this mildew stuff goes rampant. Taking care of citrus can be labor intensive until you find a rhythm. I'm not quite there yet but I'm learning a lot and feel like I'm getting closer. I'm like a parent with child number one, trying to get everything perfect.

Lol
W
nikthegreek
9 years ago
PM is not encouraged by insects. On the other hand, sooty mold is encouraged by scale and pseudococcus insect secretions. Dead mite populations also look like black or grey dust on the leaves which you can blow away easily.
Nik

This post was edited by nikthegreek on Tue, Apr 29, 14 at 12:13