In Jain Dharma this rule is mainly a traditional food–maryādā (discipline) for shrāvaks, based on ahimsā and saiyam.

From Fāgan Sud Chaudash (Fāgan Chaumāsī) till Kārtak Sud Poonam (about eight lunar months), many strict Jains do not eat dry fruits like dates, cashew, walnut, pista, etc. The reasons given by Āchāryas and Jain-granths are:

1. More jeev (life) in stored dry fruits in hot months

- In the hotter months and monsoon, dry fruits kept for long time very easily develop insects, worms and fungus. - Even if we do not see them clearly, Jain shāstra accepts that subtle lives (sūkṣma jeev) multiply in old, stored, oily foods. - To avoid this extra himsā, dry fruits are made abhakṣya (not to be eaten) in this period.

1. They are “old / stored” type of food

- Jain Dharma already tells us to avoid purāṇu / chālit-ras – food kept long, fermented, or changed in nature. - Dry fruits are usually stored for months, so in the “no‑dry‑fruit period” they fall in a stricter category of avoidance, to keep food as fresh and jeev‑sankhyā (number of lives) as low as possible.

1. Health and tapas (austerity) angle

- Dry fruits are guru (heavy), garam (heating) and rich. In the long hot / rainy season, the body is already prone to problems; reducing such foods supports sādhanā, lightness, and control over taste. - In Kārtak–winter, when it is colder, dry fruits again become allowed in many traditions for health, while infestation also naturally reduces in cold weather.

1. Not exactly same in every sampradāy

- The basic idea (ahimsā by avoiding high‑jeev, stored items) is common. - Exact dates and strictness can vary between Śvetāmbara / Digambar and also between gacchas / panths and families. - Therefore, your main guideline should always be your own Guru / family maryādā.

So, the simple answer:

• From Fāgan Chaumāsī to Kārtak month, many Jains avoid dry fruits because:

- in those months they carry more hidden life and more risk of insects, - they are old stored food, - and avoiding them supports ahimsā and tapas.

You can read a bit more on dry fruits and Chaturmās food practice here: