How to Grow Sunflowers
Planning the Site
Tall sunflowers need to be planted against a wall or fence post for better support. You’ll need to stake the plants once they become more established to protect against wind and rain damage, but planting against a support is a good idea so that the stems can bear the weight of the heavy sunflower heads. Ensure that you plant the seeds no less that 24 inches apart to avoid overcrowding.
Preparing the Site
Sunflowers need the sun. To make your sunflowers extra strong, plant them where they can benefit from both sun and shade. A spot in your garden that the sun covers during the day and that is shaded in the afternoon would be perfect.
Required Materials
To grow sunflowers, you will initially need sunflower seeds of your chosen variant and fertilizer.
Watering Requirements
Sunflowers like well-drained soil. The seeds are usually planted in May, when it is warm enough for the seeds to germinate. The roots of a sunflower can go deep into the soil (over 1.5 m). The crop is harvested in late September or in October.
Nutrients Required
Sunflowers responds best to fertilizer when soil nutrient levels are low, appropriate plant populations are used, and weeds are controlled. Optimum production of high-yielding, high-quality sunflower requires fertilization based on an evaluation of the current soil fertility level. Excessive nitrogen can contribute to decreased oil content in the seed.
Seasons
Sunflowers can withstand a mild frost. However, cover your seedlings if a hard spring freeze is anticipated. From July to September, your flowers will be bright and strong.
Expectations/Results
To harvest, cut the seed head with about a foot of stem attached and hang in a warm, dry, well-ventilated, rodent- and insect-free place. A paper bag with holes or cheesecloth can be placed over the heads to catch falling seeds as they drop during drying. Seed heads can be allowed to ripen on the plant, but cheesecloth or nylon netting will be needed for bird protection. Once the seed is dried, it can be rubbed easily from seed heads. Humidity levels must be kept low to prevent spoilage.