Hello everyone, I am hoping to get some help related to my kumquat tree. I bought it a few months ago, it was perfectly healthy, with lots of leaves and fruits on it. I am sad to say that now it looks very different (see photos) and I am afraid to do anything as I know they are really sensitive and I never had a kumquat tree before. It is kept in room temperature, with enough sunlight, and I am sticking to watering instructions ("dig the soil up to half of your finger and if it is still wet, do not water"). Anyway, I was keeping in mind not to let it sit in water. A while ago all the green leaves started drying and falling out. I read this is something that normally occurs at this time of year, but I do think there is something seriously wrong with it. The problem is, I am really not aware of anything that might have lead to this. The only thing I can think of is that once I saw a slug in the pot and removed it. I could never find another one, but finding shiny traces on the surface of the soil I was advised to dilute 1/2 vinegar in 2/3 water and pour in, which I did. I have never seen anything else, but it seems that my plant is stagnating, or dying. The trunk of the tree actually seems to be alive and not dry, but all the branches are very dry. I would very much appreciate any advice about why this might be happening and what might be the best course of action. I guess my biggest issue is should I try to re-pot it (maybe also change to a bigger pot. Also, this one, as can be seen on the photo, has those side holes, rather than bottom ones). I am a bit afraid to touch its roots but maybe it helps to find out a cause. Thanks in advance for all your help.
It is not normal for leaves to dry and fall off. Exposure to a draft, warm or cold, is possible but the problem is more likely to be under- or over-watering. The potting medium appears to be composed of fine, compacted soil particles. It would be difficult to maintain an environment with proper air/moisture levels with this mix. Once saturated, the soil will remain wet longer than desired with little air present. The tree is susceptible to root rot under these conditions. Do you water thoroughly, allowing the excess to drain? If not, then it's possible for the bottom portion of the container to remain dry even after watering. Scratch the bark on the main stem, above the graft line if there is one, and look for green tissue underneath. If there is, then it's still alive and there's hope for recovery. Much of the other branches appears to be dead; remove the ones that are brown and dried. Ease the tree out of the container and inspect the roots. Do they look healthy with white tips present? Is there any rot present? Is it root-bound? If it looks like there is a chance of saving the tree I suggest the soil be replaced with something more suitable. Typically, commercially available peat-based potting soil, which already contains some sand and perlite, can be amended to increase its porosity. This can be done by adding medium sized bark chips and more perlite. (Some opt to use CHC or coconut husk chips instead of potting soil.) The goal is to create a medium that retains air and moisture but yet is quick to drain. Decide on the size of container once you determine what root mass you'll end up with.
We can't tell from the post what the proportions of your vinegar drench was. Was it 1/2 teaspoon vinegar in 2/3 cup water, or 1/2 cup in 2/3 gallon, or 1/2 cup in 2/3 cup water? If the proportion of vinegar was relatively high then that could have killed or severely stressed the plant by drastically changing the pH of the soil. Before trying any form of pest control you need to look at the damage (if any) and then look for what kinds of pest or disease can cause that kind of damage. Slugs only damage plants by eating their leaves and do not burrow in the ground, so a vinegar soil drench would not be an effective treatment even if slugs had been your problem. A house plant won't normally have an lot of slugs, usually just one or two individuals which were brought in after a plant had been growing outside. If ever you do see slimy tracks on the soil of an indoor plant, look for a small slug or snail hiding somewhere on the pot, plant, or greenhouse shelf. Slugs like to rest in cooler, darker places where they can avoid drying out, perhaps in the saucer, or under the base or edge of the pot rim. If you find one remove it by hand; no other treatment is necessary or helpful. If the stem and roots of your plant are still fairly healthy looking I'd wash the plant roots and replace all the soil and then wait to see what happens. Never fertilize a seriously stressed or defoliated plant; you will only risk stressing it more.
