Avocado leaves turn to brown at the middle

Question

My avocado is 3 years old. Except summer time, it is always difficult time for it. Due to cold and windy weather, Avocado is always in-door during these seasons. There is not enough sun light in my place, so during day time I turn on bulb to provide additional light to it. Everything was relatively alright with avocado till recently. A few days ago, the bottom leaves started to turn brown at the middle + I can see yellow pattern on the leaves. The process is very quick (within several days).

From time to time, I was able to see a small worm in the pot, but It seemed like not to be a problem at that time. But now, I not sure.

I water it everyday around 150 ml (room temperature). From my opinion the pot is big enough.

Any help is highly appreciated.

Thank you in advance,

Additional pictures, it took 1 night, from normal leaf to these

Thank you for your comment. I stay in S. Korea, and here is end of spring. This time is usually perfect time to put it out, but now I am not sure. I will take @kevinsky advice to check the root. I will keep you uploaded. — John, May 05 '16 at 03:40
Thank you all! My avocado feels way better. What I did: 1. Wash out the sand by huge amount of water. 2. expose outside 3. use anti fug once per week (3 times, a bit) 4. give vitamins 5. water it ~ one/two times per week......)))))))))) — John, Aug 03 '16 at 06:39

score 6 · Answer 1 · answered May 04 '16 at 16:22

Bulrush is correct. Very few plants need to be watered every day. A better technique is to let the top inch of soil dry out and then water thoroughly until water comes out the bottom of the pot. You do have drainage holes in the pot?

This damage does not look like fungus/virus/bacteria to me as it lacks the alternating bands of light and dark material which is characteristic of the growth and pause cycle.

I have seen similar damage on our avocado when it was too close to a light bulb. The signs of this would be the dark area is dry and papery.

Given that the avocado is a tree that wants to grow up to 60 feet (~20 M) tall you need to keep it smaller unless you plan to get a bigger house. Consider these steps:

remove the plant from the pot and inspect the roots. Firm white roots are healthy, soft black roots indicate rot.
remove approximately 10% of the root ball from the bottom
add fresh soil to the bottom of the pot
return the plant to the pot, water thoroughly and let the top dry

This will establish if there is rot and help it grow new leaves. For a more dramatic solution just cut the plant down leaving 6 to 12" ( ~10 cm) of stem. Reduce watering, increase light and wait for a bud to start from the stem. This will force new leaf growth and keep it shorter.

Yes, there is a drainage holes in the pot. I will try your suggestion regarding the root. I will keep your informed. Thank you. — John, May 05 '16 at 03:42
Yesterday, I slightly uncover the root, and it seems like okay. However, yesterday night, I removed all the leaf with black spot, but today morning I found out other leaf with same picture (kindly find last 3 photos at main question section). Do you really think: it is not fungus neither virus? — John, May 06 '16 at 03:21
@John this looks more like fungus/virus/bacteria brought on by overwatering. Repot the plant, reduce watering, increase light — kevinskio, May 06 '16 at 09:59

score 1 · Answer 2 · answered Mar 11 '19 at 19:22

The damage is from excess salt in the soil. Avocado trees are very susceptible to excess chlorides in the soil they are grown in. Municipal water supplies are notoriously hard and contain many different minerals including chlorides. If you're indoors, you will need to water the plant with steam distilled water. Your best bet, if your plant spends time outdoors is to avoid the public water supply as often as possible, use captured rain water or rain, or water the plant with steam distilled water. In any case, flushing the container and soil thoroughly with steam distilled water will keep the condition from progressing.

Avocado leaves turn to brown at the middle

2 Answers2