When planting, it is better to put the tip part down and the large part up, because the tip part will grow roots so as to tie the soil tightly.

Bloom Time: Most sunflower varieties bloom for several weeks in midsummer.

plants about 12 inches apart.

For continuous blooms, stagger your planting, sowing a new row of seeds every two to three weeks, beginning in the spring. Succession planting, as this is called, will keep you supplied with continuous blooms until first frost.

How long does it take for sunflowers to grow? From the time you put the seed in the soil to bloom ranges between 80 and 120 days, depending on the variety.

Some varieties of sunflowers can get very tall and shade other plants, so don’t plant sun-loving companion plants too close.

Tall varieties of sunflowers work best as a screen, at the back of a border bed, or along a fence.

Shorter varieties can be grown in the middle of a border or in pots.

https://www.hgtv.com/outdoors/flowers-and-plants/flowers/growing-sunflowers-when-to-plant-and-how-to-grow-sunflowers

Direct sow mid-April to late May. Starting indoors is possible, but does not gain much time. If sunflowers are allowed to get root-bound, they will lack stability at transplant time, and will require staking.

https://www.westcoastseeds.com/blogs/how-to-grow/grow-sunflowers