Ornamental Horticulture

(b) Classification based on climatic requirements

Based on climatic requirements, annuals are classified into the following three groups:
i) Rainy season annuals
ii) Cold season or winter annuals
iii) Hot weather / summer annuals

Rainy season annuals
These annuals are grown in rainy season and can withstand heavy rains, and high humidity in atmosphere than other annuals. Seeds are sown in June and seedlings are transplanted in July.
e.g. Balsam, Cock's comb, Amaranthus, Gaillardia

Winter annuals
These annuals are able to tolerate comparatively low temperature and, hence, are comfortably grown in winter season and bloom best during this season. These winter annuals are sown in September and transplanted in October in plains whereas in hills, these are planted in February-March and July-August.
e.g. Antirhinum, petunia, nasturtium

Hot weather annuals
These plants grow luxuriantly and produce flowers under high temperature and have the ability to survive extremely high temperature. The seeds are sown in end of February or beginning of March and seedlings are transplanted in end of March-April.
e.g. Zinnia, Kochia, Portulaca, Tithonia, Gaillardia, Gomphrena, Sunflower, Cosmos.