Once
Once leaf scorch has occurred, there is no cure. The leaves that have already turned brown will not recover, BUT as long as you water properly, the rest of the plant should survive.
For example, hostas that are sufficiently shaded may still have leaf scorch symptoms if weather is incredibly hot and dry (Figure 2). Once leaf tissue is scorched, the damaged areas will not recover; however, minor damage, while unsightly, will not kill the plant.
Damaged leaves will not recover. Prune off damaged leaves and move the plant to a shadier place, or cover it with shade netting. Use fertilisers high in nitrogen to encourage the plant to replace the lost leaves. Prevention is always better than cure.
Removing leaf burn depends on a case-by-case basis. If a small part of the leaf is burned, but the plant is still getting water and functioning, it's best to just let it be. In more severe cases where the leaves are completely brown and dry, it is best to remove them before disease takes over the rest of the plant.
As sad as it is, brown tips are dead tips. You can't revive dead leaf cells, but you can make corrections and save the rest of your plant.
You will want to trim the dead or scorched foliage after properly watering. Your plant is expending energy on attempting to keep the burnt parts alive. Clip these areas off so that the energy it produces will go to the areas of the plant that are still healthy.
Stunted slow growth with yellowing leaves is a symptom of over-watering. Plants may suffer from leaf scorch or leaf burn. Water-soaked spots and blisters (Oedema) may appear on stems and leaves. The crown of the plant may rot.
Occasionally, leaf scorch is caused by a bacterial disease that can result in permanent damage or death to your tree.
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 plants with long, strap-like foliage (such as dracaena or spider plant), make your cuts at an angle to imitate the natural shape of the leaves.
Generally when a houseplant leaf turns yellow, that leaf is dying. Chlorophyll gives a leaf its green color. When the leaf loses its chlorophyll, the plant abandons it and begins to absorb leftover nutrients from the leaf. That's why once the leaf turns yellow, you generally can't make it turn back green again.
Cause and Spread
This bacterium is spread by leafhoppers and treehopper insects, although it does not appear to be spread from tree to tree very rapidly.
Once your houseplant has burned leaf margins or tips, there is no good way to reverse the damage at the injured location. The only useful thing is to solve the underlying issue and hope your plant resumes its healthy growth.
Once leaf scorch has occurred, there is no cure.
If anything, it's wise to err on the side of less sunlight—once you're dealing with sunburned plants, there's not much you can do. Since the leaves won't heal and return to their normal color, your best option is to cut off the damaged leaves and move the plant back to a spot with no direct sun.
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.
Once the damage has happened, it's OK to remove the affected leaves, which should mostly be on the outside of the plant. Or, you can let them fall off naturally (they may be protecting leaves on the inside of the plant!) Make sure you are not watering too much or too little-do the finger test.
It can take anywhere from a couple of days to a couple of months for stressed plants to recover. Recovery time depends on the amount of damage that the heat caused to the plant. If a stressed plant is completely neglected during a heatwave, it can take several months or even be impossible to revive it.
Keep them in a shady spot to give them a chance to recover: even plants that look terminally crispy can often revive and re-sprout with this treatment. Larger pots should be heavily watered, then allowed to drain – one deep watering is better than daily sprinkles.
Remove the whole leaf only if most of it is brown.
If more than half of the leaf's surface area is brown—and especially if it's at least two-thirds brown—then it's a good candidate for full removal. The preferred way to remove a whole leaf is to cut the base of its stem with sharp scissors.
What is leaf scorch? Leaf scorch is a physiological disorder that presents as discolored tissues on the margins and sometimes between the veins of tree and shrub leaves. In severe cases the whole leaf turns brown, shrivels up and drops off. Leaf scorch is, in fact, a reaction to an unfavorable environment.