Myers lemon tree leaves and lemons turning black

HOPELR · #1 May 27th, 2007, 04:50 PM

Last year we planted a Myers Lemon tree in Tampa Florida. The tree grew well and we had many big & juicy lemons.
This year the tree has black leaves and a few black lemons.
What happened and what should I do?

**skeeterbug** · #2 May 27th, 2007, 07:16 PM

You probably have sooty mold--keep the leaf litter cleaned up and spray with a copper fungicide.

Skeet

**martinpribble** · #3 May 27th, 2007, 08:48 PM

sooty mould can also be a sign of excess ant activity as ants can farm it as food. (not always the case...)

maybe check to see if there are ants trailing up and down the trunk and onto the leaves and you may be able to control the problem there.

I have an old verigated holly in my back yard (i want to get rid of it, cos it's ugly) which is covered in sooty mould. It is definitely an ant related problem in this case. It has spread a bit to a lemon next to it, but by removing overhanging branches the problem clears up on the lemon tree.

HOPELR · #4 May 28th, 2007, 06:04 AM

We are in Florida. THere has been a lot of fires in the past several weeks. We also haven't had a good rain. The air has been dirty because of the fires qaand no rain. You can see the soot that falls on pools of water. Our tree is also covered with love bugs (but everything is covred with love bugs this time of year).

Could this be part of the problem?

**skeeterbug** · #5 May 28th, 2007, 06:39 PM

Love bugs are definitely not the problem. I would think you could tell if the black on the leaves is soot from fires and it should fall off in the wind or with a little water spray, but sooty mold is a fungus that can grow on the leaves and prevent photosynthesis-- like putting a black plastic bag over your tree.

Skeet

**martinpribble** · #6 May 28th, 2007, 06:47 PM

Some people say you can wipe down the leaves with olive-oil.

I can see how this may work as it will clean the leaves and wipe away any fungus, but for me olive oil is too expensive and I can't imagine wiping down my 70yr old lemon tree one leaf at a time.

I would usually opt for an organic solution for fungus etc, but in this case it may be more worth your while opting for the copper-based fungicide.

ces594 · #7 May 29th, 2007, 10:27 AM

I'm having the same problem. (San Leandro, CA, San Francisco Bay)

I just bought a house and the tree is in the corner against a fence, gets sun almost all day except when the sun starts to set. The bottom portion of the tree branches are covered with black stuff (what i think is mold) and there are ants all over this portion of the tree. This portion is still producing fruit, but they are smaller.

The top of the tree is good and is producing lots of flowers and lemons. How do I treat the rest of the tree? I was told to prune it because it's not getting enough air. Do I just cut off this whole portion? or is there a remedy? The tree is big and very mature.

Thanks for your responses.

**martinpribble** · #8 May 29th, 2007, 04:13 PM

This may help you. Sooty Mould Management. This is about as concise as it gets.

I have also heard that lemon trees need good airation, so prune out the central portions, and some of the top section to give it a "vase" shape. You don't want lemons right at the top where you can't reach them anyway.

ces594 · #9 May 29th, 2007, 04:49 PM

Thanks martin. I've never pruned anything, what tools do I need and how should I determine what to cut off?

**martinpribble** · #10 May 29th, 2007, 05:49 PM

OK for starters you need some good shears. Fiskars make some really nice ones, but they are pricey. It's always worthwhile getting good shears, as they'll last forever if you don't leave them out in the rain.

Secondly, go here http://www.ehow.com/how_3642_prune-citrus-tree.html for basics on pruning the tree. Don't prune too closely to the trunk or you could get some die-off below the cut.

That's about it really.

ces594 · #11 May 30th, 2007, 02:40 PM

Excellent. Thanks a mill martin.

ces594 · #12 August 27th, 2007, 09:29 AM

Update: My tree is looking very good. I've pruned it and got rid of most of the sotty mold and ants. I used tanglefoot around the base of the tree.

The problem I have now is that it seems that the ants have farmed in one of the knots in the tree and I don't know how to get rid of them. Any suggestions?

Other than that, I have a whole new harvest coming in with lots of flowering. Beside watering the tree, is there something else I should be doing so that I can expect a big harvest every year?

**martinpribble** · #13 August 27th, 2007, 04:07 PM

the ants could be controlled with a poison, but I guess it depends on how big the nest is. Try shooting some white oil inot the knot and see it that makes a difference.

ces594 · #14 August 28th, 2007, 09:15 AM

Martin, What is white oil?