I have answered this question before, hence, writing the same here as it might be
helpful.

I have answered a similar question before and hence pasting the same here might help.

At first, you need to understand why the tips of your plant have turned brown. Water in the plant flows through its roots and stems to the leaf’s tips at last, so if the plant (due to some reason) doesn't get enough water, other plant parts get served first and the tips start turning brown as they miss out on required water.

This is not only due to lack of water or fertilizer but also due to the abundance of it as plant parts are unable to absorb the water properly if it is supplied too fast. Whether the plants are kept indoors or outdoors, the reasons for the tips turning brown remain the same in all cases.

• Once they turn brown, those dead tip cells cannot be revived but you can surely save the rest of the plant from dying by taking good care of it.
• You need to examine the roots, soil and make sure your plant has a proper drainage system whether it's planted in a pot or on the ground.
• Try to learn more and more about the plant you have by reading blogs or taking workshops so as to learn how to identify the signs that indicate the health of your plant.
• The quality of fertilizer also plays an important role, hence, make sure you use a good quality fertilizer to nourish your plants.
• Cut the brown part of the leaves carefully with a scissor to get past this problem and nourish your plant back to health by taking good care of it.

You can check out The Affordable Organic Store as they have good quality fertilizers at affordable prices online with various sales and discounts and they conduct regular workshops to educate people about how to take good care of their plants.

Hope it helps!

Prima di tutto, dovresti cercare di capire perché è marrone e croccante. Controllare l'umidità del suolo - ci sono buone possibilità che il terreno sia troppo umido. Considera la fertilizzazione - fertilizzi molto (tipo ogni mese) o non fertilizzi mai? Ci potrebbero essere problemi minerali o di pH. Guarda la luce, fai una piccola lettura sul tipo di pianta. Se fai dei cambiamenti (come lasciare che il terreno diventi più secco), taglia le punte marroni e vedi se il ribaltamento continua o no, il che indicherà se il problema è sotto controllo. Se non riesci a trovare una ragione specifica, puoi andare avanti e tagliare la foglia.