Citrus - healthy trees, so little fruit!!

[ourarka]

Hi all,

I've been growing citrus in pots for several years and whilst I appear to have healthy trees, that flower prolifically, I always seem to have a very disappointing amount of fruit. I am aware that fruit drop isn't uncommon but they are all several years old now and I'm really not sure what the answer is!! Internet searches give hundreds of different answers, and am hoping a UK grower might be able to offer some good advice. I've varied techniques over the years - this is how they're kept now. Pictures below - as you can see, all look really healthy (with the exception of the Meyer, which has had a bit of leaf drop in the recent storm - I'm aware they're pretty quick to dump some leaves!!)

• All kept outside in a sheltered spot for majority of year (except Valencia Late, which is just under an overhead canopy for extra warmth)
• All are SE facing
• In winter, all are kept frost free when temperatures drop (quite rare down here)
• I prefer to dictate watering in winter, so soil surface is kept covered
• Watered according to a 'moisture sensor' reading - quite surprised by how 'dry' they are and I have certainly watered more this year than normal
• All in a very free draining, predominantly loam mixture
• Fed with a specialist dilute citrus feed at almost every watering (as per feed instructions)

Looking forward to any pearls of wisdom .........

[burnie]

According to this you need to keep them indoors a lot more https://www.rhs.org.uk/advice/grow-y...n/fruit/citrus

[ourarka]

Thanks - the problem is really during summer. They winter well down here, sheltered, out the rain and the rare occasions it gets cold (rather than cool), they come in to an unheated conservatory. Citrus need cool, bright and humid over winter so I’m pretty certain that the problem is the other half of the year!!!

[ameno]

Is that really such a disappointing number of fruit? Seems reasonable to me. They are very small trees, after all. A full sized citrus tree is some 8-10ft tall. Really, we should count ourselves lucky that they fruit at all at such a small size; most fruit trees don't.

[Plot70]

I started what I believe is a pink grapefruit in a mix of Derbyshire clay and coal mine waste.
It boosted up with lush green growth after a top dressing of ericacious compost.
Have a look at the sequence of photos starting off with a flower while it was so small that I thought the plant was crazy.
https://www.growfruitandveg.co.uk/gr...flowering-size
Some people say they should be in ericacious compost and others don't comment.
I just set the compost ratio according to the average view.
If your loam is from that over blackboard chalk soil that is common in parts of the south of UK the lime content might be a bit harsh for them.
Give them a top dressing of something with a bit of acid in it. I have used rosemary clippings on blueberries with good results but in this case I would use bagged aricacious to start with.

[TrixC]

Are you getting lots of flowers but fruit not setting? Or are you not getting many flowers either?

[TrixC]

Also where are you located? You say “down here” but not where that is!

[ameno]

Also where are you located? You say “down here” but not where that is!

If you click on the user profile it shows their location (assuming they entered it). They're in Hastings.

[TrixC]

If you click on the user profile it shows their location (assuming they entered it). They're in Hastings.

Oh, my mistake. Did it previously show in the profile next to each post or have I imagined that?

[TrixC]

And re-reading the original post I see the OP also answered my question about flowering

A few things to say then.

First, I agree they are quite small trees, and the amount of fruit on them is not too bad all things considered.

The UK climate is marginal for citrus. The issue of winter frosts can be handled by bringing them indoors, but nothing can be done about our short, cool summers, and the fact that we're at a high latitude with limited light outside the peak summer season. Citrus need heat and intense light to fruit well.

The other suggestion would be that feeding every week is quite a lot, and could be causing the trees to put on a lot of vegetative growth at the expense of fruit. Many trees fruit better if under a certain amount of stress. I would maybe try cutting the feeding back to once a fortnight, and see if that makes any difference.

I doubt if it's a pollination issue because citrus are normally very attractive to bees, but if you don't notice many around you could also try hand pollination.

[ameno]

Oh, my mistake. Did it previously show in the profile next to each post or have I imagined that?

Before the site update it did, yeah.

I doubt if it's a pollination issue because citrus are normally very attractive to bees, but if you don't notice many around you could also try hand pollination.

Most citrus are parthenocarpic, anyway, so don't require pollination in the first place.

[TrixC]

Before the site update it did, yeah.



Most citrus are parthenocarpic, anyway, so don't require pollination in the first place.

Yes but pollination improves fruit set. And not all are parthenocarpic, most mandarin varieties require pollination for example.

[ourarka]

Thanks all - appreciate the input. Yes, Hastings, and I’m a bit higher up and a mile from the coast. A pretty gentle climate down here!!

As for flowers, generally plenty - just poor fruit set.

The feeding thing has always puzzled me - almost every care guide recommends nitrogen rich feed, which goes against general rules of fruiting plants!! The rationale seeming to be that a healthy canopy of leaves is the bedrock for a happy, fruiting plant.

I also find watering not easy either!! Anyone have any truly reliable moisture sensors? I find ‘feeling the soil’ is all good and well in theory, but in reality is not easy as it is compacted, or a bit cold (so feels wet!). My moisture sensor seems good, until it hits loose, very free draining soil. It’s convinced my Yucca rostrata has a saturated, even though it gets watered about once a year!!!

[Snoop Puss]

I've tried to see from the photos but I can't tell. How many fruit do you get off each tree? Even though they may be a few years old, the trees are not that big and maybe the amount of fruit you get is what they can support.

Also, does anyone else have a view on the pot size? Might they be a bit small, or is that typical? Not trying to carp, I really have no idea, but my initial thought was the roots need a bit more room.

[Bhilltop]

I've grown various citrus trees in containers for about ten years now, and there are a few things I've learnt about getting them to fruit. I have tried to move them in and outside but have not had a huge amount of success that way. The best approach for me (albeit these are 'ideal' and not everyone can do this) is to have them in a permanent position all summer against a south-facing wall. So even on the cooler nights, they get the radiating heat off the bricks, same applies to my fig trees. So ideally...

1. Permanent position if possible, ideally under glass if you have a greenhouse or if you put them outside leave it late and put them against a South-facing wall in a sheltered spot, avoid wind
2. Don't let them dry out when flowering or fruiting - the kiss of death
3. Use a slow-release citrus fertilizer, here are a few good ones, I like to use the spikes as they are the easiest. Just don't overdo it, say 2 small spikes are fine. Don't use the huge ones they will kill the tree

If you use do keep them under glass in a greenhouse or conservatory, remember to let pollination happen!!