For outdoor plants, especially newly planted plants or plant seedlings, they can be prone to lack of watering. Remember that you need to keep watering enough for a few months when the tree is small or just planted. This is because once the roots are established, Kumquat can rely on rain most of the time. When your Kumquat is planted in pots, overwatering is often more likely to.When you accidentally overwater your Kumquat, you should be prepared to remedy the situation immediately. First, you should stop watering your plant right away to minimize the effect of your overwatering. After, you should consider removing your Kumquat from its pot to inspect its roots. If you find that none of the roots have developed root rot, it may be permissible to return your plant to its container. If you do discover signs of root rot, then you should trim away any roots that have been affected. You may also want to apply a fungicide to prevent further damage. Lastly, you should repot your Kumquat in soil that is well-draining. In the case of an underwatered Kumquat, simply water this plant more frequently. Underwatering is often an easy fix. If you underwater, the plant's leaves will tend to droop and dry out and fall off, and the leaves will quickly return to fullness after sufficient watering. Please correct your watering frequency as soon as underwatering occurs.