My Calamondin tree lost a lot of lower leaves and several branches dried out in the last year. It does however keeps flowering almost every month and there are even a few fruits growing up, so I'm assuming all is not lost. It seems to lack something because very few fruits grows large enough to mature, most fell off the tree when they are the size of a sweet pea. I'm thinking it probably needs a lot more foliage to help with photosynthesis, but even with all the new flowers, it barely grows any new leaves, and then only at the extremities of the existing branches. Is there a way to help it to grow more foliage, and new branches off the main stalk at the lower level? I was thinking of pruning the top leaves, but most articles recommend to prune at most 25% of the canopy, which is almost nothing in my case. Can I just cut back all the branches to half their size to force new growth? Or will that cause it to suddenly die? I don't really care on losing the existing fruits/flowers, I would prefer that it grows back strongly and flowers later.
Perhaps it would do better in a location with more light, like that from a window with a southern exposure. Also, the tree appears to be some distance away from the window. Some fruit drop before their maturity is normal for citrus; the tree keeps only those it can support. I would not prune the tree until it shows more robust growth; I think it can use all the leaves it has left to recover. Do you regularly fertilize the tree?
I don't understand, why do you want to remove these last leaves of your citrus tree? The tree obviously sufers from light deficiency. Move the plant closer to the window or add a grow light.
The plant is normally on a windowsill facing west, I moved it to the floor only for the picture. In the summer, when a lot of leaves fell and branches dried, it was outside on a balcony also west-facing. As my apartment is facing northwest, that's the best light it can get. I used to fertilize it once a month with fertilizer (25-10-10), but I have stopped since it lost so many of its foliage. There are some new leaves (hardly visible on the picture), but the problem is they always grow on top and the bottom leaves get discarded regularly, so the tree just kept getting higher and thinner.
There are a lot of discussions on this forum related to problems when growing Calamondin. I believe you could learn there something useful for you, search for calamondin site:forums.botanicalgarden.ubc.ca. As for myself, I would repot the plant at the end of winter giving it a bigger pot and suitable container soil, prune at the same time one of the branches at the level where you would like new growth to start, and see what will happen. I would also protect the pot from getting too hot when on the balcony in summer.
I would just added a grow light. A LED light, that is hung into the crown so that lighting conditions would radically improve inside the crown, would create possibility for thicker crown growth and should not become too hot . If new branches with fresh leaves appear under current leaf storey, only then I'd pruned some longest branches if more compact form is desired. This should help to avoid massive leaf dropping in summer too, as this was probably caused by abrupt exposing shade leaves to intense direct sun, together with drying winds.
