Is your flower turning yellow, dropping leaves and looking like it has a couple of days left to live? Don't rush to throw it away!
Often the problem is that the roots are suffocated in the old soil. Carefully remove the plant from the pot, shake off the soil and inspect the roots.
If they are brown and slimy, they are rotten.
Cut off the damaged areas, rinse the remaining roots in a weak solution of potassium permanganate and leave to dry in the air for 2-3 hours.

For epiphytes (orchids, phalaenopsis), replace the substrate completely, removing old bark and moss.
If the roots have almost completely rotted, do not despair - in many plants, even small healthy shoots can be revived. For example, in zamioculcas (dollar tree), the tuber is able to produce new shoots, even if all the stems have died.
Take a new pot with drainage holes, pour expanded clay and fresh soil on the bottom.
Plant the flower, but do not compact the soil - let the roots breathe. Water only after 2 days, adding "Kornevin" to the water to stimulate growth.
Cover the plant with a transparent bag, creating a greenhouse, and place it in the shade. After a week, remove the bag and gradually accustom it to the light.
If the leaves have started to revive, but look wilted, spray them with a solution of succinic acid (1 tablet per 1 liter of water) - this will restore their elasticity.
But what if the roots are completely rotten?
Try to root healthy cuttings. You can cut off a leaf from begonias, violets and spiderworts, put it in water or plant it in damp sand.
And for succulents, break off a leaf, dry the cut for 2 days and place it on the soil - in a month roots will appear.
For a money tree or a ficus, the air layering method is suitable: cut the bark on a healthy branch, wrap it with sphagnum moss and film. In 3-4 weeks, roots will appear under the film - then the branch can be cut and planted.
One more secret
If the plant has suffered from waterlogging, replace the soil with a looser one. Add perlite, vermiculite or coconut fiber to the soil - they will improve aeration.
For cacti and succulents, mix the soil with coarse sand or fine gravel.
If the flower has dried out, revive it using the "water bath" method: place the pot in a basin of warm water for 30-40 minutes so that the soil is saturated with moisture. After that, let the excess water drain and cover the plant with a bag for 24 hours.
Don't forget about the temperature regime. Tropical plants (orchids, anthuriums) recover faster at +25–28 degrees Celsius, and succulents prefer coolness (+18–20).
If the leaves are covered with spots, it may be a fungus. Remove the affected areas and treat the plant with Fitosporin or a soda solution (1 teaspoon per 1 liter of water).
And in case of pest invasion (spider mite, scale insect), use a soap-alcohol solution: 1 tbsp. liquid soap, 1 tbsp. vodka per 1 liter of water. Apply the mixture with a cotton pad to the leaves, then wash off after 2 hours.
Important advice
After resuscitation, do not fertilize the flower for at least a month. Its roots are too weak to absorb fertilizers.
The first signs of success are the appearance of new leaves or shoots. But even if the plant survives, do not expect rapid growth - it needs time to recover.
For example, an orchid, after losing its roots, can gain mass for a year before blooming again.
Lifehack for "hard cases"
Use hydrogel. Soak the granules in water, mix with soil and plant the flower in them. The hydrogel will gradually release moisture, preventing drying out or overwatering.
And for plants with aerial roots (monstera, philodendron), build a support from moss - wrap a stick with sphagnum, secure with a fishing line and regularly moisten. The roots will begin to grow into the moss, receiving additional nutrition.
And finally: not all plants are worth saving. If a flower is infected with a virus (leaves are deformed, covered with strange patterns), it is better to destroy it so as not to infect others.
Also hopeless are specimens with a completely blackened trunk or root collar. But in 80% of cases, by being patient and following simple rules, you will bring back to life even the most hopeless "patient".
Remember: plants, like people, fight for life. Give them a chance - and they will surprise you with their resilience!
For example, a friend of mine was able to revive a cactus that had been lying on the balcony for 2 years without watering. She simply planted it in fresh soil, and a month later new needles appeared from the wrinkled "stone". So don't rush to say goodbye to your green friend - perhaps its story is not over yet.