First, you need to consider the location. You must ensure that the particular area receives ample sunlight. Before you begin planting the seeds, consider the amount of sunlight and the direction of the wind. Sunflowers need a full sun, so choose an area that gets steady sunlight for at least 6 hours.
Always ensure you plant the seeds at least one inch deep into the soil. You must also keep a distance of 6 inches between each seed. Avoid planting sunflowers just before the winter season. If you have to plant them in pots, ensure that you keep these pots on a windowsill that comes in the way of plenty of sunlight.
It is said that these plants can be grown in a variety of soils. As per experts, sunflowers prefer soils that drain well and have a lot of mulch. Mixing some manure to soil a few days before planting seeds also helps greatly. This non-fussy plant, hence, can be grown without worrying too much about soil requirement.
This plant needs plenty of water as well. Ensure you water it on a daily basis to prevent them from getting withered in the sun. This is also the basic reason why you must use a well-drained soil. Seedlings should be watered deeply during the initial months. This will ensure that they develop healthy roots.
Always remember that you need to think about other plants in the garden as well. Tall sunflower plants can block the sunlight and the wind for other plants. This can be useful if you have planted varieties that require less sunlight and the shade provided by the sunflowers can be a blessing in disguise.
Downy mildew is one such disease, which is a kind of fungi that grows beneath the leaves. This can also cause the stem to blacken. Keep a daily check to keep beetles away. These are known to eat into the plant, damaging it in the process.
Insects can pose a big problem as well. In that case, the most useful insect would be the bee, because they help in the process of cross-pollination. Some of the common insects found in the plants are the sunflower midges, sunflower beetles, sunflower bud moth, gray sunflower seed weevil, sunflower stem weevil, etc.