Zinnias fell out of favour for a while with home gardeners, but they are now back in fashion with a vengeance.
Tetra Flowered “State Fair” is a lovely old series of giant dahlia-flowered zinnias from the 70's. A time tested winner that performs well in the garden and in the vase, and is great for attracting bees and butterflies to the garden. The semi-double blooms are large and long-lasting. The blooms grow to around 10 to 15 cm (4 to 5in) wide and come a full range of bright uniform colours including scarlet, pale rose, orange, bright pink and dark pink.

State Fair is a tall and sturdy plant and an excellent choice for cut flower growers. They have greater tolerance to diseases than other cut flower zinnias. The thick stems are less likely to bend when being cut and the blooms have a longer vase life.
Zinnias are the perfect flower for beginners, they are extremely easy to grow from seed and provide colour from mid-summer to autumn. No wonder the latest flower 'must have' flower in the garden is the old fashioned Zinnia. .

Sowing: Late Spring to Early Summer
Zinnias grow quickly and may bloom in just 45 days. Successive sowing every few weeks beginning from April through early July will ensure continuous flowering throughout summer.

Sowing Indoors: March to April
For early flowers, start indoors four to six weeks before the last frosts are expected. Use trays or pots and a good sowing compost. Seeds should be spaced at least 2.5cm (1in) apart. The seeds need light to germinate, so “just cover” the seeds with a sprinkling of fine, sieved soil. Seeds will germinate in 7 to 14 days. Keep soil moderately moist during germination.
When plants are 3 to 5cm (1 to 2in) in height, transplant to 7cm (3in) pots and grow on. Zinnias are sensitive to root disturbance, so be especially careful when transplanting. Gradually acclimatise indoor started seedlings outdoors after all danger of frost has passed and weather has warmed considerably. Plant out 25 to 30cm (10 to 12in) apart. Add garden compost to the soil if it is heavy or infertile.

Sowing Direct: April to May
Sow seeds where the plants are to be grown in spring after the last frost, and in an area with full sun. Zinnia prefers fertile, rich, and well-drained soil, average soil is acceptable, but if you add compost and all-purpose fertiliser before sowing, the blooms will be lusher.
Sow seeds 5 to 7cm (2 to 3in) apart in rows 30cm (12in) apart. Barely cover seeds with soil; they need light to germinate. Keep soil moist until seeds germinate, in 5 to 10 days. When 5cm (2in) tall thin the seedlings to 25 to 30cm (10 to 12in) apart.

Cultivation:
Zinnias require full sun. They thrive in hot areas as long as they get enough moisture. They like rich soil and appreciate a slow-release fertiliser in the spring when they are planted and a booster shot of fertiliser in mid- to late simmer. Zinnias need to be watered if there is less than an inch of rain each week, sooner if they appear to be wilting. They will reward you with hundreds of colourful flowers for just a little care.
If you are growing some of the older, heirloom varieties of zinnias, a little pinching back in early summer will make them bushier and produce side branches with more flowers.
There is typically little problem growing zinnias, except in extremely humid conditions where a powdery mildew can sometimes form. Protect young plants from slugs and snails. Deadhead spent flowers frequently to prolong flowering.
Water regularly. Water deeply by soaking soil and avoid spraying foliage.

Saving Seeds:
Saving seeds of zinnia saving could not be easier, you not only get the colours you want, but you can also select seeds from the healthiest plants. Do this, and in a couple of generations of seeds, you will have developed your own strain of zinnias selected to perform well in your conditions.
In late summer let some zinnias go to seed. The seeds are easy to collect and store for next year. Wait until they are fully dry on the plant, then clean out the old petals and store at room temperature.

Cut Flowers:
Zinnias are the perfect cut flower--the more you cut, the more you get. When cutting the blooms for the vase, trim off all the foliage; unlike the long-lasting blooms, it does not age well.

Plant Uses:
Cottage/Informal Garden, Cut Flowers, Flowers Borders and Beds. Container Gardening.

Nomenclature:
Zinnias are native to Mexico, where Aztecs originally dubbed these flowers mal de ojos meaning "hard on the eyes".
The Zinnia got its name from 18th-century German botanist Johann Gottfried Zinn, who wrote the flower's first scientific description.
When zinnias were introduced to Europeans, the flowers were referred to as "poorhouse flower" and "everybody's flower" because they were so common and easy to grow. They were also once popularly called "youth and old age" because old blooms stay fresh as new blooms open.
More than 100 zinnia cultivars have appeared since breeding of the flower began. Dwarf zinnias can be as short as 25cm (10in) tall; the giants reach up to 120cm (4ft). They come in single, double, and semi-double blooms, with a variety of flower shapes. Zinnia flowers come in every colour imaginable, except blue.