Sunflowers are real garden workhorses. Much more than just a pretty face, these annuals are favorites for many pollinators, provide food for birds (as well as for the gardener!), can support vining plants such as beans, and provide height in the garden. Every garden should have some! With that in mind, here's how to grow sunflowers in your garden.
Sunflowers need to be started from seed, and it's best to sow them directly where you want them to grow after your last spring frost date. Starting them indoors and transplanting them is not recommended, since sunflowers really dislike having their roots disturbed.
Depending on the variety, you'll want to sow your sunflower seeds 12 to 24 inches apart. Sunflowers require full sun (at least six hours per day -- the more, the better.) They prefer soil that is of average fertility, moist and well-drained. You can add a little compost to the soil before you plant; this is all the fertility these plants will need.
Keep the area free of weeds while the plants are getting going so they don't compete with your sunflowers for space and water. Very tall sunflowers may start falling or bending over, especially once the flower heads start getting heavy with seed. You can stake them to keep them from toppling over.
How to Grow Sunflowers
Sunflowers are actually very easy to grow. If planted in a sunny location, they'll grow quickly, and bloom in mid to late summer. Make sure that they get about an inch of water per week, and keep the area weeded. It's also a good idea to mulch around your plants to keep the soil from drying out.
Sunflowers don't need to be fertilized during the growing season. In fact, too much high-nitrogen fertilizer will result in weak stem growth, and you'll likely end up with a floppy sunflower.
Sunflower Pests and Diseases
Sunflowers are rarely bothered by pests and diseases. The most common issue you'll run into with sunflowers is powdery mildew. Most often, this is due to lack of air flow around the plants.
Another issue you may run into with sunflowers is that birds and squirrels will try to eat the seeds. If you've planted them for wildlife, then no problem. However, if you're trying to grow sunflowers to harvest the seeds for yourself, you'll want to protect the flower heads while the seeds mature. You can buy mesh bags for this, or simply place a paper bag or some tulle fabric over the flower head. It's not very attractive, but it does the job.
Recommended Sunflower Varieties
The type of sunflowers you'll want to grow depends largely upon why you're growing them. Are you growing them for seeds to eat? Or do you just want a pretty addition to your garden? Do you want something super-tall or something that will fit well into a flower border?
There is such a huge variety of sunflowers that you'll be able to find something to suit your purpose. Seed catalogs and seed packets will both have information about not only whether it's a good sunflower to grow for seeds for snacking, but also the size and color of the sunflower blossoms. If you're not into bright yellow, you can also find sunflowers in white, cream, red, and dark mahogany shades. There are diminutive sunflowers that you can grow in containers, and there are enormous ones that grow twelve feet tall, or taller. So read your seed packets so you know what you're getting!