THE blooms of the plant Catharanthus roseus and a number of plants in the genus Zinnia have been gracing gardens for decades.
The C. roseus plants are perennials while zinnias are annuals. But both these old-time favourites make the compound bright and beautiful. And breeders are also constantly offering exciting new varieties in refreshing colours and forms.
The C. roseus, known by its common name of Old Maid, is a woody herb from the dogbane family, Apocynaceae. This plant is also known as Madagascar periwinkle as it originates from there. Being a desert plant, it can withstand heat and drought well.
The plant’s glossy dark green leaves are oval to oblong in shape. The flowers have five petals, are delicate-looking and are white to dark pink, with darker red centres. This upright plant can grow to about 90cm high.
In addition to those wild types, hybrid synthetic varieties or cultivars (C. roseus x hybrida) bred in recent times have expanded the colour range of the blooms, improved bloom size, increased flowers, prolonged the blooming period and have superior heat tolerance.
Madagascar periwinkles don’t only come in white and pinks but also in red, dark pink, blue and orange shades. Their growth habits can be either weeping or upright. Performing best in full sun
locations, they’re usually between 30 and 60cm high and grow into a rounded form.
Medium textured, these plants can be cultivated in pots as edgings or as ground cover.
F1 and interspecific hybrids
Mainly natives of Mexico, though some originate from tropical North and South America, the species in genus Zinnia (of which there are 20) have composite flowers in the form of flower heads. They belong to the daisy family, Asteraceae, and are from the New World.
Zinnias (Zinnia spp.) thrive best in hot and dry conditions and selected new varieties can withstand humidity. Some of the more popularly planted species are Zinnia elegans, Z. angustifolia, Z. tenuifolia and Z. haageana.
But, most zinnias available in the market are actually interspecific hybrids, including those derived from Z. elegans and Z. angustifolia (created the Profusion series) and also F1 hybrids like those of Zinnia elegans.
In the garden, their blooms rise up above the foliage to add striking colour and beauty to sunny borders or in pots. They come in single, semi-double or double forms, and in various sizes. The petals range in colour, from white, pink, red, and yellow to orange, green and can even be multi-coloured. The leaves are pale to medium green and are linear to ovate in shape.
Plant height ranges from 25cm to over 90cm. You can grow the short and spreading varieties as ground cover or in pots, window boxes and in front of borders or raised beds. Larger varieties are grown for cut flowers as the flowers are borne on tall sturdy stems and have a long vase life.
Cultivate them as annuals in rich well drained soil in locations with a full sun. Zinnias grow easily from seeds. Directly sow the seeds in the ground or pot and water regularly to ensure they don’t dry out.
Deadhead to extend bloom period.
Tips
* Your garden will be abuzz with winged visitors as bright flowers attract butterflies, birds and bees.
* Zinnias can cross-pollinate. To preserve their original form, grow different varieties in different sections of the garden. If you have a small compound, grow only one variety.
* For more flowers, apply a bloom-boosting fertiliser when the plant starts flowering.