Kaffir lime leaf growing single leaf

Question

The plant leaves turned yellow, fell off, grew back dull dark green and as a single leaf. We’ve fertilised and watered more and there isn’t a difference. We live in Tasmania, is it just too cold here? Planted in a rock garden, full sun, well drained next to a lavender bush. Thanks for any advice.

• 

Answer 1

Kaffir lime has a double lobe segmented leaf, the leaves in your photo do not. Your plant has huge thorns, which is not typical. Kaffir lime usually grows true to seed so grafting is not necessary. But in your case there may have been an exception, because from the photo it appears to be a different variety of citrus. It's possible that when the original foliar crown died back, a sucker or multiple suckers from the root stock, below the graft, has grown up and is not true to the kaffir lime variety that was grafted on to another citrus root stock.

So if you take a look at the very bottom of the stem, you may be able to see if all the current growth originates low, below the area of what would have been a grafted top stock. If this makes sense, and there is no new growth from above the graft, then you may want to remove the existing tree and replace. If there are some segmented leaves in sections of the crown, then remove all the lower growth from below the graft and preserve the Kaffir lime sections.

https://www.gardeningknowhow.com/edible/fruits/lime/care-of-your-kaffir-lime-tree.htm