Zinnia

Native to Mexico and Central America, Zinnias are old garden favorites. There are two main types of zinnia, garden, spreading and crosses between the two. This annual plant will grow between 6 and 40 inches in height with single and double blossoms. Garden Zinnia has solitary daisy like flower heads on long stems and bristly oval shaped leaves. There are a lot of varieties of about 20 species with bright colours like lavender, orange, pink, purple, red, rose, salmon, white, yellow, even green etc in different sizes. Zinnias can be used as borders,  in pots and containers or as background plants and are excellent fresh cut flowers which may last a week or more. 

Zinnias are easily grown in evenly moist, well-drained soils in full sun but in very hot climate it may benefit from light afternoon shade. Zinnias generally grow well in warm climates.

The propagation is through seeds. Seeds can be sown directly in the ground and it will germinate in one to two weeks. To encourage quick growth and best performance, enrich the soil with compost and transplant in ground 30cm apart according to variety or in pots. Zinnias are sensitive to root disturbance, so be especially careful when transplanting. If the taproot is disturbed, the double flowers may revert to single forms. The plants may also self-seed in the garden and some varieties are available from nurseries. Successive sowing every couple of weeks beginning from April through early July will ensure continuous flowering till winter. Most zinnias will bloom around three months to bloom from seed.

If growth is slow or leaves look pale green, fertilize with a soluble or controlled release fertilizer. Pinch young plants when they are 4-6inches high to promote compact, bushy growth. Good air circulation helps prevent onset of fungal leaf diseases. Deadhead spent flowers weekly if possible to promote additional bloom and maintain plant appearance. Mildew is a common problem for zinnias in rainy or humid climates which causes powdery white spores on the leaves drawing out moisture. It can be controlled by spraying a solution of 1/2tsp baking soda in 2quarts of water and a few drops of liquid soap.