Lemon tree leaves suddenly dropping fast (April/May) [Help, please!]
BenHayward
Posts: 20
Hi Everyone!
My lemon tree (four seasons lemon tree) has gone through the entire winter without dropping any more than 2 or 3 leaves. Then suddenly at about mid April (and still ongoing) it is dropping about 4-7 leaves per week!!
I quickly realised that I might not have been watering it as much as I did, so increased the amount of watering appropriately. I was previously giving it about 2 pints of water per week which left the soil very dry. I am now giving it about 4-5 pints per week, ensuring they the soil doesn't get too saturated so as to avoid root rot.
However, the problem is ongoing, and the tree has now lost half of its leaves since April (it's mid May at time of writing) and I don't know what I can do!
I give it winter citrus tree feed during the winter, and have recently been giving it summer feed (Vitax 200g Citrus Feed for Summer/Winter - Amazon). The tree is located in a sun lounge, the radiator behind it is not used. The plant gets direct sunlight for a good number of hours each day. As you can see from the images, the tree has one maturing lemon and two small fruit which seem to have 'taken' (began to grow).There are a number of tiny fruit which have not taken.
Would you please provide some help with this? I can't understand what I'm suddenly doing wrong. It has been quite maintainable up until now!
Many thanks in advance! 
PS: Those lighter green leaves at the top are reasonably new. Some are darkening up. Mainly old darker leaves dropped, but now new ones are too.
Edit: The leaves look wet because (a) I spray the flowers with water as apparently that helps with pollination and (b) I've read that they prefer humidity rather than a dry atmosphere. I generally spray once every 1-2 days.
Last edited: 17 May 2017 21:34:03
Posts
As I can see you have veiny leaves and this is caused by thrips they suck the sap from the leaves and this will cause the leaves to drop. I had the same problem. They are very small , brown and hard to see but if you look very carefully you will see them on underside of leaves. I tried using neem oil but this didn't help so I had to succumb to a bug killer. Repeat as necessary as they will hatch every week. You can also get them off with your fingernail. This is a common problem with citrus trees. Ongoing I am afraid until you get on top of the infestation. Good luck, we both need it.
Thank you for your responses!
Hilary, I had a good look around the leaves this morning and couldn't see any thrips. The veiny leaves looked free of anything. I've attached some photos of the underside of the leaves. Could it be anything else?
Mike, as mentioned before, that radiator is permanently off. I shall certainly not give it any food whilst it's recovering though. I don't believe I've over watered - I felt that I'd underwatered before.
I'm not a citrus grower, but those leaves would generally indicate a magnesium deficiency.
Which may in turn indicate that the compost is out of nutrients (or at least that there's an imbalance of nutrients that has locked out Mg).
Try googling Interveinal chlorosis.
If you agree, then get some Epsom salts from the chemist dilute a T-spoon of epsom salts in a litre of water and spray the leaves.
Once should be enough
Last edited: 18 May 2017 08:24:15
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
I've done a bit of reading and as it's the younger leaves that are affected, it's more likely to be an iron deficiency than magnesium.
So chelated iron may be the answer.
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
Hi Pete, doing a Google image search, there are very similar images appearing, so that's certainly something I'll look into! Would iron deficiency cause leaf drop? Can you recommend a fertiliser to help? ... Searching "chelated iron"yields some unexpected results!
Many thanks!
... More image to follow, can't upload on mobile!
It will cause the leaves to drop. Once the plant detects that a leaf isn't earning its keep, the plant disposes of it. It's what happens in autumn to deciduous trees
I should have said sequestered iron - I guess chelated iron is for humans!
e.g. http://www.ebay.co.uk/itm/BRAND-NEW-DOFF-SEQUESTERED-IRON-PLANT-TONIC-5-X-15G-SACHETS-/332210659416?_trksid=p2141725.m3641.l6368
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
Thank you Pete, I've just ordered some of that. Very much appreciated!
Is there anything else you feel I should be aware of with my plant in the condition it's in?
Seaweed extract is a great tonic for plants and I know Monty Don uses it on his citrus.
Patience is the other thing you need. It takes time for anything we put on plants to have an effect, so you'll need to wait a few weeks or more before seeing any improvement.
As I mentioned before I don't grow citrus, so have no specialist knowledge in that area - just 50+ yrs of learning by help from others and my mistakes
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
That's just what I was going to say. I used to have a lemon that looked like this with the veined leaves. Since applying seaweed fertiliser, it's been much happier. Overwatering can also be a problem with lemons but so can underwatering. It's difficult to get it just right.
I recall Monty did a section on GW recently on citrus that you may find useful - link below
http://www.bbc.co.uk/iplayer/episode/b08qhg3j/gardeners-world-2017-episode-9