When plants have too little water, leaves turn brown and wilt. This also occurs when plants have too much water. The biggest difference between the two is that too little water will result in your plant's leaves feeling dry and crispy to the touch while too much water results in soft and limp leaves.
Determine which by feeling the leaf showing browning: if it feels crispy and light, it is underwatered. If it feels soft and limp, it is overwatered. Yellowing leaves: Usually accompanied by new growth falling, yellow leaves are an indication of overwatering.
When a plant is first becoming overwatered, leaves turn yellow. If soil doesn't have a chance to dry out before you water again, leaves start to wilt. When overwatering is the problem, wilted leaves are soft and limp. (If too little water is the issue, wilted leaves are dry and crispy.)
The good news is that most plants will bounce back between 7-14 days if they're given proper care (which includes rehydration). If this isn't possible because major damage was done or little healthy root system exists then expect about 2 weeks until improvement can be seen.
There is never a guarantee that your plant can bounce back from overwatering. If your plant is going to survive, you will see results within a week or so. At this point, you can move your plant back to its original location and resume watering it as normal.
Signs of root rot are slow growth, mushy stems, and wilting, yellow, distorted leaves (especially when the plant has been well watered, as wilting leaves can also be a sign of a dry plant).
Whilst it's easy to mistakenly think an overwatered plant is suffering from underwatering, it is much easy to identify an underwatered plant. Look for dry, papery leaves, brown leaf tips, leaf curling, wilting, and slow growth.
One of the quickest, first signs of overwatering your plants is to observe occurs at the tip of the leaf. If the tip of the leaf is turning brown this is a sign of overwatering. Too little water will result in your plant's leaves feeling dry and crispy to the touch while too much water results in soft and limp leaves.
How often should plants be watered? Water once or twice per week, using enough water to moisten the soil to a depth of about 6 inches each time. It's okay if the soil's surface dries out between waterings, but the soil beneath should remain moist.
Plants in containers dry out a lot faster than plants in the ground. Pots absorb heat, which can stress plant roots, and the soil in them dries out much faster than soil in the ground. Container plants generally need to be watered daily.
Poor drainage or improper watering
Water issues — either too much or too little — are the leading reason behind yellow leaves. In overly wet soil, roots can't breathe. They suffocate, shut down and stop delivering the water and nutrients plants need. Underwatering, or drought, has a similar effect.
Hydrogen peroxide can help to control fungal growth and fungal infection, such as root rot, by preventing the growth of fungi. It can also help kill fungus and bacteria on plant roots.
If you catch the disease early enough, it is possible to rehabilitate your plant. You will need to take the appropriate steps to treat the root rot to give your plant a second chance. Unfortunately, if the root rot is left for too long and there are no remaining healthy roots, your plant can't recover.
Container Plants
Containers dry out more quickly than garden beds, so it's best to increase watering in the summer. During heatwaves, water container plants twice a day, once in the morning to give plants a boost before the sun begins to bake down, and once in the evening to replenish what the day took away.
A yellow leaf has lost its chlorophyll (pigment) and it can't turn green again even after you correct the problem. Don't worry, if the plant regains its health, it's possible that new leaves will fill in during the next growing season. Growing plants is always a matter of patience.
Plants growing in soil that is too wet suffer from a lack of oxygen which leads to the death of roots and a loss of vigor in the plant. Stunted slow growth with yellowing leaves is a symptom of over watering. Plants may suffer from leaf scorch or leaf burn.
Place the container in the water and let it sit for about 15 minutes so that the soil can soak up all the moisture it needs. Larger containers need to sit for a bit longer, and smaller containers for bit less time. Keep an eye on things. If the soil soaks up all of it during those 15 minutes, add more.
A gentle soak for an hour or two is better than puddling soil around your plants and moving on. It primes the soil to absorb more water and allows the water to spread out in the soil. It can take a few tries to get it right, and you don't have to be obsessive about getting exactly eight inches.
Using a hairdryer directly on the soil is an easy way of removing that excess moisture easily. However, there are some things to take into consideration when doing so. When directed at the soil the dryer will only remove the moisture from the surface having the rest of the soil wet.
The best time to water is early in the morning when it's still cool, which preps the plants for a hot day, but that's not always easy to accomplish with a busy schedule. The second-best time is late in the afternoon or early evening.