Overwatering
Watering issues are generally the most common cause of yellowing leaves.
Check watering practices as over- and under-watering can lead to these symptoms. Plants that are under-fertilized will often develop yellow leaves. Low humidity will cause the browning and eventual drop of leaves.
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.
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.
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.
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.)
When a leaf is yellowing, let the leaf fully turn yellow before pulling it off. When a leaf is on its way out, the leaf loses all of its chlorophyll (the molecules which make the leaf green), and the plant absorbs any leftover nutrients from the yellowing leaf.
Nitrogen deficiency shows up as a general yellowing. Older, inner leaves turn yellow first. As it progresses, yellowing moves outward, eventually reaching young leaves, too. Potassium deficiency shows itself when leaf edges turn bright yellow, but the inner leaf stays green.
As for the leaves that still have brown tips, you can snip the dead parts away with a pair of scissors without hurting the plant. For some plants that have long, strap-like foliage, such as dracaena or spider plant, make your cuts at an angle to imitate the natural shape of the leaves.
The brown leaf tips will not turn back to green but you can trim the brown edges to get the plant back to looking healthy. Find out more here. If your are noticing brown patches all over the leaves, this could also be a sign of overwatering.
Your plant's leaves may be turning brown due to insufficient light, too much or too little water, pests and diseases, or even factors like the amount of fertilizer in its soil. Most often, brown leaves are caused by improper water and sunlight for the plant's needs.
If it feels soft and limp, it is overwatered. Yellowing leaves: Usually accompanied by new growth falling, yellow leaves are an indication of overwatering. However, yellow, curling lower leaves can also be an indication of underwatering. Check the soil for moisture to decide which it may be.
Stop Watering the Plant
But stopping your watering is always the first step. If you're overwatering, you'll likely notice that the soil is wet, so you want to make sure that soil is bone dry before you're ready to break out the watering can again.
Epsom Salt for Plants
Aside from the anecdotal evidence about human benefits, Epsom salt does seem to help plants. Generations of gardeners have said it helps their plants grow bushier, produce more flowers and have better color. It's also said to help seeds germinate and repel slugs and other garden pests.
Plants need light, but too much of a good thing can affect your plant's health and cause leaves to turn yellow. Sunburn may cause dark burn-like spots on leaves or can cause full yellowing of leaves receiving too much sun.
Q. 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.
Watering issues
Giving your plant too much (or too little) water can cause yellowing leaves. "Excessive watering can suffocate a plant's roots," Blank says. "This causes root rot, which prevents the plant from absorbing nutrients properly and results in yellow leaves.
Below are six signs you can easily recognize to determine if you are giving your plants too much fertilizer: Yellowing and wilting of lower plant leaves. Browning of leaf margins and tips. Black brown or rotting roots.
To dry out soil quickly, you can apply hydrated lime to the soil, add compost and then turn the soil thoroughly to aerate it.
The key is to be patient. Keep tending to your plant for a few weeks and then reevaluate. “Once you've taken steps to revive a dying plant, it can take up to a month before you start to see an improvement or new growth, so don't give up on it too soon,” says Valentino.