Any chance this Calamondin tree can be saved?
I have a mature Calamondin tree that had been bearing plentiful fruit for years but started dying since last June. I was away from home for three months and my automated sprinkler system broke in the middle of California drought. All existing leaves have been wilting and turning yellow. Fruit shriveled and then turned black, I see no new flowers or leaves. A couple of new big branches with huge leaves started growing out of the trunk which I cut off thinking they would be suckers. Looks like the tree is dying. Thinking it may have suffered from drought, about a month ago, I put a soaker hose under its canopy on a sprinkler timer that runs for 5 minutes in the morning and evening. I am advised to feed it with Citrus fertilizer high in Nitrogen but I don't see any Citrus fertilizer at Home Depot with high Nitrogen. Is there anything I can do to save it?
Yep! The top of the plant is in severe stress and decline.
I can tell from the picture that the tree was grafted, and the top may be dead or dying while the root-stock is still alive. The calamondin was probably grafted onto a wild rootstock, perhaps sour orange, which is extremely hardy. Take a good look at the trunk. About an inch or two from the soil line there is a difference in bark texture. Above that point carefully scratch the bark (into the cambium) with a knife to see if the cambium is still green and not dead (brown). If you see green or light green tissue then the top has a chance to survive. You may try cutting the tree back severely (1/3 to 1/2 or more) and wait for re-budding to occur. The pruning action reduces the size of the calamondin top and will help to relieve stress and allow for regrowth (on a smaller plant after pruning) without trying to regrow a bunch of limbs on a larger plant.
If above the graft union appears to be dry and tan or brown, then the top is dying or dead. And, the large leaves that you are seeing is regrowth coming from the root-stock. The good news is that the roots are alive. However, if the calamondin top is dead you will have 2 choices: 1) let the root stock grow in to a nice wild plant and re-graft a calamondin onto it. You will be back into production in 2-3 years; or 2) pull up the tree and replant a new calamondin which should begin to bear fruit in 2-3 years as well.
Also, apply a root-stimulator or root-activator. These are weak fertilizer solutions with a rooting hormone. Local nurseries or garden centers sell the product. Apply according to label direction and do not add extra.
Also, mulch the surface of the soil with a organic material that is slightly acid-forming such as pine needles or pine bark.
Good luck with all this.
Thank you, Vincent for sharing your expertise. Yes, the large leaf growth was below the graft. I have followed your instructions and checked a few branches (pictures attached) and they are all green. As I understand it, you're recommending pruning the tree to about 1/2 its height and wait for re-budding to occur. I'll also apply root-simulator and add pine bark/needle mulch to the surface under canopy. I am hopeful it will survive.
I also checked for moisture in the soil and it is quite moist down to 8 inch depth. I assume I need to cut down on watering it. When should I apply fertilizer and in what ratio?
Well that is a bot of good news! Try cutting back 1/3 instead of 1/2 as soon as your time allows; followed by the root activator or stimulator and mulch. Yes, cut back on watering, as the mulch will help conserve water.
Done with pruning. Will follow the advice and hope for the best. If it doesn't show any signs of growith in 3-4 months then will think about re-grafting or planting a new one.