Apartment plants

Suffering Sanseveria

Question: what happens to my sanseveria?

I don't understand why my Sans. suffers. I found a completely dry leaf. It is located in a dim place, so every day I take it behind the windows of a window where there is more light and in the evening I put it back in place.
Is it still in the purchase vessel (1 month) do I have to transfer it?
Thanks so much!

Sanseveria suffering: cultivating the Sanseveria

Dear Marina,
the Sanseverias are vigorous and resistant plants, which also tolerate very poor cultivation conditions, drought and poor luminosity; to have a healthy and luxuriant plant it is advisable to find a well luminous position, which in summer also favors the production of long floral spikes: the flowers of Sanseveria they are intensely scented, even if not very showy or decorative.
To have a healthy plant it is important to be very careful with watering: it is watered only when the soil is dry, and in the winter months only sporadically, once every 10-12 days; to know if it is the right time to supply water, just dip a finger in the soil, if it is fresh and moist, we postpone watering. As I said before, the Sanseverias can survive very well even in unfavorable conditions, so it often happens that their suffering is delayed, when they have long been cultivated in a not perfect way. In general, the leaves shrivel or become soft when the soil remains moist for a long time, especially in winter. From March to September we begin to water more frequently, especially for the plants placed on the balcony or in the garden, but always waiting for the soil to be dry between two waterings. We always avoid that the water stays in the saucer for a long time.
Now you should remove the damaged leaves at the base, cutting them with a sharp and clean knife, and repot the plant, placing it in a slightly larger pot than the previous one, filled with a good fertile and very well drained soil. Wait at least ten days before watering again, and then, if possible, keep the plant on the terrace, in a bright place, until the autumn cold arrives; throughout the fall and winter you can leave your sanseveria in a place that is not very bright, water it sporadically.