Why are my Guava leaves brown?

[Imran]

Need Help for Guava plant. Leaves are half de-shape and brown in colour in Melb. Any solution plz

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[EricL]

Hello @Imran

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about your Guava tree.

The condition of a plant's leaves is often a reflection of the plant's overall health. The common causes of leaves turning brown are leaf scorch due to weather, disease/fungal infection, herbicide damage, and excess application of fertilizer.

Can you please tell us a little bit about your Guava plant? Have you recently applied fertilizer to it? Were there any other plants close to it several weeks back? Is it in full sun or shade? What kind of watering schedule did you have for your Guava tree? Did you add soil to the Guava tree? How long have you had the tree? I know that these are a lot of questions, but the more information you can give us the better we can diagnose what's wrong with your Guava tree.

Looking at the pictures you posted it might be a form of fungal infection. Can you please post a picture of the bottom of the leaves?

Let me tag our experienced members @Adam_W and @Noelle for their opinion on what could be wrong with your Guava tree. 

If you have any other questions we can help with, please let us know.

Eric

[Noelle]

Hi @Imran 

My first thought is that browning of leaf edges, like your guava is exhibiting, is due to moisture stress - either too much or too little watering - rather than disease or sun exposure.

If it was too much sun, entire leaves would be burned and if it was too much fertiliser, it would probably show up first close to the stems and along the veins of leaves. It may also be a result of cold winds/draughts.

As Eric has suggested, we need more information to be able to give you a more accurate diagnosis.

[Imran]

Hi @EricL @Noelle 

Thanks for your reply

Please find attached the  images of back side of leaves. I have two plants which they have same condition 

Please find below more information

Have you recently applied fertilizer to it? yes I have used some all purpose complete garden fertilizer with two weeks gaps spray of Power feed fertiliser

Were there any other plants close to it several weeks back? There are mongo and blue berry tree  close from the last 2 years

Is it in full sun or shade? in full sun 6-7hrs

What kind of watering schedule did you have for your Guava tree? Manuel 2-3 times a week as per Melbourne rain 

Did you add soil to the Guava tree? Nop

How long have you had the tree? 2 years

Please suggest your advice.

@Imran

[MitchellMc]

Hi @Imran,

Given the details you've supplied, I'd like to explore @Noelle's theory of moisture stress. Since you're watering 2-3 times a week, I doubt it would be too little. What's the drainage like on the pot? Does the water freely drain out the bottom?

I'd suggest removing the saucer off the bottom of the pot and only watering the plant when the top 5cm of soil becomes dry. If the top 5cm is still damp, don't water it. 

Can you please tell us a little more about the all-purpose garden fertiliser? How many times did you apply it, and want quantity did you use?

Mitchell

[Noelle]

Thanks, @Imran 

There's no sign of disease on the undersides of the leaves, so my hunch is that it is a moisture stress and heat condition.  Because the tree is growing in a pot sitting on concrete, the potting mix can become quite warm, which in turn overheats the roots, causing them to dry out rapidly.  Guava trees are best in large containers (half wine barrel size) or planted into the ground where the roots will be cooler and moister for longer after watering.

The tree currently has only a small volume of potting mix around its roots - not enough to sustain it long-term. My recommendation would be to either report it into a much larger pot or plant it into the garden by the start of spring. It is not going to do well in a pot.

[MitchellMc]

Some great advice from @Noelle there, @Imran. I'd agree that the plant will perform much better in a larger pot or in the garden. 

Mitchell