How to revive underperforming citrus tree?

[Lisbeth1]

I inherited theseold citrus  3 years ago and have been trying to resurrect them. Cool temperate, NSW.  I have cleared the grass underneath them and mulched. I have seasoled frequently and fed very 6 months. I have removed old wood and most diseased parts of the tree. I have treated for scale frequently using eco oil. Every summer I get good growth and plenty of blossoms but by mid winter all the tiny fruit has died and the leaves turned yellow like in the pictures. Should I just give up and pull them out?

  

 

[robchin]

Hello @Lisbeth1 

I can feel your frustration here. Good on you for your persistence. Seems like you have done most of the things right here. Couple of comments/questions: 

- The yellowing of the leaves in the cooler weather is normal. Not too be stressed about. As long as it greens up again when it warms up. 

- When you feed - what are you feeding with? Because they are heavy feeders - you need to use a specialist fertiliser for promoting flowering and fruiting, higher in Phosphorus and potassium, lower in Nitrogen. I work at Bunnings and we sell this this one for example: Richgro 2.5kg Black Marvel Fruit And Citrus Food - Bunnings Australia

Or a liquid version which could be taken up quicker when it warms up a bit: Yates 500mL Thrive Citrus Liquid Plant Food - Bunnings Australia

Cooler weather now so don't bother doing it till it warms up a bit. 

- I don't think you'll need the Seasol if you are consistantly fertilising

- In terms of lemons dropping off small - this could be a number of things but generally inconsistent or in-frequent watering. Water regularly and deeply. 

- Thinning fruit - even established trees may have some problems producing lot's of fruit every year. Have you considered thinning the fruit? Just rub off say 1/ - 1/3 of the flowers and this will give those that remain more energy to produce good fruit. 

- One last thing - have you checked the pH? Always a good idea. 5.5 to 7 is OK but they do like it a little bit acid. 

Good luck. 

[JacobZ]

Hi @Lisbeth1,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Rob has already hit on the main points that I would be looking at with fertiliser and water being the two main things.

My experience with a lemon tree at my parents' place, was that despite applications of Richgro Black Marvel Fruit And Citrus Food, the fruit was still small and struggling to develop. The one thing we changed that made it produce far better fruit was the amount of water. We started watering them deeply 2-3 times a week during the peak growing and fruiting seasons and the fruit started to grow stronger and larger.

I would suggest you look at your watering schedule and likely increase it during those important parts of the year.

Soil pH would also be worth checking. Have a read through How To Test And Adjust Your Soil Ph for some guidance.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[Lisbeth1]

Thank you for your feedback and knowledge. So this isn’t fungal?

[Lisbeth1]

Thanks so much for your reply, I’ve been using seamungus and mushroom compost as well as a multi mineral. I was worried this could be a black spot fungal disease, what is your feedback?

[EricL]

Hello @Lisbeth1 

It does not appear to be fungal as the leaves appear to be in good condition and there are no tell-tale signs of soot, widespread rust spots or folding or curling leaves. Just to add to the suggestions made by my teammates, I recommend lightly aerating the surface of the soil to break it up and allow more nutrients to flow down to the roots of the tree. Please make sure to not go too deeply to avoid hitting the roots.

If you need further assistance, please let us know.

Eric