According to plant and seed company Burpee, sunflower seedlings should be pruned in order to create a sturdier and more wind-resistant adult plant. Seeds must initially be planted in groups of 2 to 3 seeds. When the seedlings reach a height of 3 to 4 inches, all but one strong seedling is snipped off. Extra garden soil is then carefully filled in around the one remaining seedling.
Roots typically develop from the stalk of the seedling to help anchor the plant and give it a sturdy foundation. According to Home Guides at SFGate, sunflowers that grow too tall for the garden can also be pruned. When they become too tall, they are pruned back by removing the top bud, which encourages the plant to develop a shorter, bushier growth pattern.
Many varieties of sunflower develop side-suckers that can produce new flowers, making the plant bushier rather than taller. Wilted leaves should also be pruned from sunflowers to freshen their look. After sunflowers finish blooming, they start to develop a ragged appearance, so it improves the look of the fall garden to cut them down to the ground. Some sunflowers are perennial plants, and these varieties often grow back and bloom again the following year.