Prakruti means two things in Ayurveda. It denotes both body constitution and nature. Prakruti is affected by the movement of the earth and planets. Changing seasons will not only affect the surroundings but will also affect the doshas and hence the body.
The main aim of Ayurveda is maintaining the health of the healthy. For this the ancient scholars prescribed Ritucharya. Ritu means season and charya is activity. For each season there is a unique ahara (diet), vihara (lifestyle) and routine (charya). Ritucharya is designed to preserve health from seasonal health imbalances.
Ayurveda divides each year into two sections. One is called uarayana where the sun is in the northern hemisphere. The sun is here closer to Earth. The seasons which are found here are shishira (winter) vasantha (spring) and greeshma (summer).
The other is dakshinayana where the sun is in the southern hemisphere. The seasons here are varsha (monsoon), sarath (autumn) and hemanta (early winter).
Shishira is from mid-January to mid-March. There is severe cold and this increases jataragni (digestive fire). The jataragni is concentrated in the kostha (alimentary canal).Hence heavy, oily foods can be digested. Vata is also increased producing a dryness in the body. So, oil therapies like abyanga or massage of head and body is advised. The taste which is helpful in this season is sweet and sour. Spicy, bitter and astringent foods should be avoided. Cold foods also should be avoided. Travelling should be restricted. Bala or strength is the most in this season.
Vasantha is from mid-March to mid-May. In this season the kapha which had accumulated in the winter is beginning to melt. Due to the melting of the kapha the jataragni is also diminished, hence heavy and sweet foods should be avoided. Barley, wheat, rice and soup are advised. Vigorous exercise is also advised. Any daytime naps should be avoided. Oil massage is advised. Shodhana treatments like vamana and nasya are advised. The strength in this season is medium.
Greeshma is from mid-May to mid-July. Here the sun is very powerful and dries everything. The body becomes weak and the jataragni is weak. Hot foods, excessive exercise and exposure to the sun should be avoided. Plenty of fluids should be taken. Avoid pungent, salty foods that could aggravate pitta. Eat sweet, cold and light foods. Do not exercise excessively. Short naps are good. The strength of the body is less.
Varsha is from mid-July to mid-September. In this season all the three doshas are imbalanced. Here the jataragni is also weakened and vata is aggravated. Eat bitter, pungent foods. Avoid the rain and wind. The strength is weak.
Sarath is from mid-September to mid-November. Here pitta is aggravated hence purgation and bloodletting is advised. Bitter, light and cooling foods should be taken. The strength is medium here.
Hemantha is from mid-November to mid-January. Here the jataragni is increased. Oil massages are advised.
By following these routines, the doshas will be kept in check and aggravation will be prevented.