Sunflower Giganteus is just like it's name says a very gigantic, very large sunflowervariety with beautiful, large, bright yellow flowers with a contrasting dark brown till black hart. The flower is carried by a very sturdy, long, greyish green stem surrounded by greyish green leaves. The attractive black-white striped seeds are happily eaten by birds. This plant needs a very sturdy and high support and it needs also a lot of space. Giganteus is also very attractive to bees and butterflies. Sunflowers are fun to grow with children because they're very easy to grow. Non hardy annual. Height: 2 - 3 meter.
Indoor sowing/under glass: April - May
Outdoor sowing: end of May - August
Germination: 14 - 21 days
Germination temp.: 20 - 30 °C
Sowing depth: ½ - 1 cm
Sowing in rows: 30 cm
Plant distance: 60 - 90 cm (depends on size of sunflower)
Plant position: sunny and sheltered
Flowering period: July - October
Sow indoors in April in a seeding tray or individual pots in a heated propagator and put away in a heated greenhouse or a warm room. The soil temperature needs to be at least 20°C. You need to keep the temperature as even as possible, also during the night, to ensure a better and quicker germination. When You use individual pots sow 2 seeds per pot in pots of about 10 cm Ø. Cover the seeds with a layer of soil of about ½ - 1 cm. Keep warm and moist.
Transplant the seedlings, when they're about 5 - 8 cm in size, to bigger seperate pots. Harden the seedlings gradually of for a couple of days, in the beginning of May. Put them on a sunny plot with some shelter against the wind in the middle of May, when there's no longer any danger of nightfrost. Keep 60 - 90 cm apart, depending of the size of the plants. Support Your sunflowers when necessary.
Sow outdoors from the beginning of May, when the weather is warming up and there's no longer any danger of nightfrosts. Sow in a well prepared sowing bed or in a large container of flower pot. Sow 2 seeds per hole and keep them about 60 - 90 cm apart, depending on the size of the sunflower. Cover the seeds with about ½ - cm soil. Press gently and keep moist. Give Your sunflowers a sunny plot with shelter against the wind.
After 14 - 21 days the seedlings emerge. Remove the weakest seedling in each spot. You can replant those seedlings elsewhere. Keep about 60 - 90 cm apart. Keep moist and weedfree. Proctect the seedlings against slugs and snails. Give them a sunny and sheltered plot. Support the plants with strong bamboo sticks.
