Lemons not ripening and fall off tree

[blankamark]

Hi, we have an approximately 4-year-old lemon tree (in Brisbane) and it has a lot of lemons now, yet they don't seem to ripen, they fall off before they mature, have brown spots outside and are also brownish inside with no juice. See photos. Any idea what is causing it? Thank you.

 

[Jason]

Hi @blankamark,

Welcome to the Bunnings Workshop community. We trust you'll get loads of ideas and advice from our clever and creative community members for all your projects around the house and garden. 

Thanks for the great photos of the fruit. Could we also please trouble you for some wider shots of the tree? It might help members to diagnose the problem if they can see the health of the whole tree. It might also be useful to know the growing conditions (whether the tree is in a pot or what kind of soil you have planted it in) and your watering and feeding regime. 

Please provide a little more detail and I can tag some of our helpful horticulturalists in the community to share their thoughts. 

The Bunnings guide How to grow and care for a lemon tree is also a fantastic resource. 

Thanks,

Jason

[blankamark]

Hi @Jason,

thank you for your quick reply.

The tree looks pretty healthy, it is growing in the garden in the full sun.

I fertilise it from time to time with Seasol fertiliser. Not sure about the soil to be honest. We have had quite a lot of rain in summer, so sometimes I wonder if it can be some kind of root rot. I don't think it is caused by insects. Please see some additional photos.

 

[Tyro]

Hi @blankamark 

Some time back I asked a fruiterer about this and he said it looked like a root disease.  If your soil is dodgy, you might need to dig out the tree and replant it in a hole filled with high quality soil and compost.  

I knew a lady who had large healthy lemon and lime trees in her garden.  She said she spiked the soil 15-20cm deep (about 20cm apart) all around the root area and watered with a good plant food in Spring & Summer.  This allows the roots to better absorb the nutrients.   She also put blood & bone on them.  I've also been told that uric acid is also beneficial (you need to do some research on easiest access to that! 🤣)

I'd also recommend you visit the horticulturalist at your local Bunnings.  Those folk not only have a wealth of knowledge but are lovely to talk with! 😁

Good luck! 🤞🏻

[MitchellMc]

Hi @blankamark,

I notice that at least two of the three lemons you are showing on the ground have a section of branch attached to them. When lemons drop prematurely from a tree, they don't typically take the branch with them. Do any cockatoos like to play in your tree and rip off fruit? I think these lemons have been removed rather than fallen off themselves. Perhaps this was just a small example of the dropping phenomenon, and others have been falling off by themselves.

The second thing I noticed is your lemons have quite a thick pith section to them, and coupled with the no juice, it's throwing a couple of flags that these could be from a rootstock variety that is bred for rigour and not tasty fruit. However, you have a fairly definitive trunk and no real signs that the rootstock has overgrown the grafted plant. That's not to say it didn't happen very early on in the plant's life.

The odd brown spot on a lemon isn't all that unusual. It could be a disease, or it could be from some type of physical damage. If all the fruit have a similar brown spot to them, then it's a call for concern.

Please note that Seasol is not a fertiliser. It's a tonic that helps a sick plant feel better. Seasol is like a warm soup on a winter's day, it's lovely to have, especially when you are feeling down, but it's not a full meal. You need a fertiliser like Scotts Osmocote 500g Citrus and Fruit Controlled Release Fertiliser, which is more like a steak and vegetables, with dessert afterwards. If you've only been applying Seasol, then I'd suggest the plant is quite devoid of nutrients.

I'm going to call in a few of our gardening enthusiasts, @mich1972, @Noelle and @LisasGarden to see if they have any thoughts.

Please let me know if you have any questions.

Mitchell

[blankamark]

Hi @MitchellMc ,

sorry for the confusion, we have cut some branches off and therefore there are some lemons attached to the branches on the ground. The tree just have a lot of lemons.

Thats interesting what you say about the tree variety as we bought that tree at Bunnings so I would assume that variety would not be sold?

Thank you for your help.

Blanka

[MitchellMc]

Hi @blankamark,

Just about all lemons are sold grafted onto a growing stock. This growing stock provides the plants with the vigour of the root variety. It means that the grated variety receives a huge boost in growing power from the roots. The root variety, at times, can throw suckers, which are shoots. If these shoots are allowed to grow and not cut back, then they can easily overpower the grafted variety and eventually kill it off. The fruit of a rootstock normally has a thick pith, little juice and is not tastey. Its fruit normally is a bit more gnarly than yours, so I suspect this might not be a case of an overgrown plant, plus your trunk doesn't show any signs of it. Rootstock has been bred over the years for vigour, so it typically has horrible fruit, whereas classic lemon varieties have been grown for beautiful fruit but at the cost of vigour.

Mitchell

[Noelle]

Hi @blankamark 

In your first post you mentioned you had had a lot of rain - which makes me suspect your tree is suffering from "waterlogged" soil.  That is, the roots are wet for too long and the excess moisture is not draining away.  While citrus like soils that retain moisture, they do not like wet feet and will react accordigly by dropping fruit.

The other reason for dropping fruit is that the trees is not physically capable of ripening all the fruits that are developing, so it sheds some of them in order to survive.

AS Mitchel has suggested, a regular feeding program with a specific citrus fertiliser will be beneficial.

Some of the brown spots like like snail or slug damage, while the smaller ones may be as a result of too much moisture. Browning inside the fruits is also symptomatic of the soil being too wet for too long.

Thinning of the fruits so the tree is less stressed, improving the soil quality and therefore also the drainage and feeding every 6 months with a controlled release fertiliser should see an improvement over time.

[MitchellMc]

Thanks for your expert opinion @Noelle!

Mitchell

[mich1972]

@Noelle  Is the best !!! Waterlogged soil will definitely affect the tree fruiting and showing signs of stress. Also @MitchellMc  has given great advice as well 🍋🍋🍋