Study of Important Flowering Annuals
Annuals are a group of plants which attain full growth from seed, flower and die in one year or one season. Mostly they complete their life history in 3 to 6 months.
They comprise of several of the most beautiful and easily grown plants widely varying in form, habit of growth and colour.
Uses of Annuals:
Annuals find a variety of uses in landscaping:
1. Flower beds of simple design can be laid out on the outskirts of lawn, along the base of buildings, in the path leading to entrance of houses and on sides of footsteps.
2. Certain annuals are useful as edging e.g. Dwarf Marigold, Alyssum and Candytuft.
3. Certain annuals are useful in hanging baskets e.g. Petunia, Verbena and Alyssum.
4. Certain climging annuals are useful to cover trellis work e.g. tall Nasturtium and Cobaca scaridens.
5. Some annuals are useful for massing in beds e.g. Asters; Phlox, Salvia, Zinnia, and Verbena.
6. Few other annuals are useful for planting in shrubberies in vacant spaces; they are Sunflower, Holly hock, tall growing species of Amaranthns, Tithonia etc.
7. They serve as perennial sources of supply of cut flowers for indoor decorations.
Classification of Annuals:
Annuals may Roughly be Grouped as Follows:
a) Rainy season annuals, which can stand more rain than others and therefore, grown to flower during the rainy season. The time for sowing them would-be from April-May in most of the places.
b) Cold season or winter annuals thrive and bloom best during winter. They are sown in September to October.
c) Hot weather annuals which are required for blooming from March to May and are sown in December – January.
Hints in Raising Flowering Annuals:
1. Sow the seeds in seed pan or raised beds. Thin sowing is necessary to get good sized vigorous seedlings. In the seed pan, a pot mixture consisting of two parts of well sifted soil, two parts of leaf mould and one part of sand may be used.
2. Fine seeds may be mixed with 3 to 4 parts of sand before sowing.
3. Annuals which do not stand transplanting like Calendula and Antirrhinum are sown broadcast in beds.
4. Watering the nursery may be done with rose can.
5. After the seeds germinate completely, then out over crowded seedlings.
6. As transplanting often results in heavy casualities the seedlings are pricked before transplanting. Pricking is the practice of transplanting young seedlings into small pots individually or in the nursery beds with richer soil giving wider space (10-13 cm), pricking is normally done when the seedlings are produced 2-4 leaves. This helps to increase the fibrous root system and to develop vigorous plants.
7. One month after planting when the seedlings have produced six to eight leaves, they can be transplanted into main bed.
8. Generally a spacing of 30 x 30 cm may be given for most of the annuals.
9. Tall growing annuals like Hollyhock may be providea with stakes.
10.Pinch off the terminal buds of seedlings after they establish and when they are about 25 to 30 cm high. This encourages lateral growth and a more bushy shape.
A description of some of the commonly grown annuals are as follows :
i) Summer and Rainy Season Annuals:
90-120 cm, tall, ornamental foliage. Requires sunny situation. Bears dropping spikes of white or crimson colour.
2. Balsam (Jmpaliens balsam in a} : 20-60 cm gall bearing single or double flowers of varying colours.
3. Celosia argentea (Cocks comb) : 25-30 cm tall. The flowers are feathery of various colours, yellow, red, orange.
4. Gaillardia pit left ella : 40-45 cm tall. The flowers are large, single or double, of various colours such as yellow, lemon yellow etc.
5. Gomphrena globosa : 30-50 cm tall, flowers are button like in shades of white, orange etc. Useful as cut flowers.
6. Cosmos bipinnatus : 90-150 cm height; flowers white, pink, yellow, can be grown throughout the year.
7. Dahlia veriabilis : 90-150 cm height; flowers white, pink, crimson etc; useful for beds and pots.
8. Althaea rosea (Hollyhock) ; 120-180 cm height; flowers of various colours.
9. Tage/ea patitla (Marigold) : 30-40 cm height, red, orange yellow flowers.
10. Hetianthus attnus (Sunflower) : In all varieties (150-180 cm) flowers rotate with the Sun movement. The flowers are big and yellow.
11. Zinnia elegans (Zinnia) : 80-120 cm height; flowers white, red, pink colours.
12. Helichiysum bracteaturn (Straw flower) : 50-80 cm height, bear ever lasting flowers, flower colour silvery white, rich yellow.
13. Petunia hybrids : .20-45 cm height; flowers trumpt shaped, colour of flowers pink, red pale blue.
14. Salvia sptendens (Salvia) : 60-90 cm height; flowers are terminal spikes with tubular scarlet flowers.
ii) Winter Season Annuals:
1. Antirrhinum majus (Snapdragon) : 30-90 cm height; numerous spikes of crimson and white colour.
2. Callistephus chiftsnsis (Aster) : 40-50 cm height, colour of flowers white, pink, blue. Useful as a commercial crop.
3. Calendula officinalis: 40-50 cm height; colour of flower yellow, orange, good for cut flowers.
4. Iberis amara (Caijdy tuft) : 30-40 cm height; flowers pink, white.
5. Dianthus caryophyllus (Carnation) : 45-75 cm height, flowers white, pink, yellow colour. Long vase life. Useful for cut flowers.
6. Centaurea cyan us (Corn flower) : 90-»100 height,-colour of flowers while, pink, blue.
7. Delphinium ajacis (Larkspur) : 45-150 cm height; colour of flowers white, pink crimson. Useful for cut flowers.
8. Atyssum marltimum (Sweet aiyssum) : 10-30 cm height; flowers colour is white.
9. Centaurea moschata (Sweet sultan) : 90-100 cm height, white, yellow scented flowers. Useful for cut flowers.
10. Lythyrus odoratus (Sweet pea) : 90-150 cm height, white, pink, orange scented flowers.
11. Viola tricolour (Pansy): 25-30 cm height; colour of the flowers is yellow, blue, red.
12. Senecio cruentus: 25-45 cm height, colour of flower blue, purple.
13. Tropaeolum majus (Nasturtium) : 30-45 cm height. Colour of flowers yellow, orange red, Grosn in rockeries.
14. Verbena hybrida ; 25-45 cm height. Purple, pink. Blue coloured flowers.
15. Papaver rhoeas (Poppy) : 60-75 cm height, flower colour scarlet, red, white, purpoel
15. Phlox drummondil : 30-50 cm height; colour of flowers white, red, blue. It can be grown in baskets, pots.