Bright, cheery sunflowers are a welcome addition to vegetable and flower gardens. These annual plants are native to North America and were cultivated at least 3,000 years ago by native people, according to Colorado State University. Today, they are grown commercially for their oil and seeds. Sunflowers have a short life span. They grow 8 to 10 feet high, depending on the variety, and bloom within 50 to 60 days of planting. Within four months, the seed heads fill with seeds, droop and shrivel. Thereafter, the plant begins to brown and die.
Difficulty: Moderately Easy
Plant sunflowers in a sunny location and water the soil to keep it evenly moist but not soggy. Pull weeds that may grow around the base of the plants. Sunflowers generally require little maintenance and produce vigorous growth if planted in an appropriate location.
Inspect the undersides of the leaves for aphids and other leaf-sucking plants. Sunflowers may prematurely die or become stunted if infected with a large population of insects. Spray the leaves with a garden hose to drown the pests, or treat them with an insecticidal soap.
Cut the seed pod with a knife when it turns down and becomes slightly shriveled if you want to harvest the seeds. Otherwise, leave it for the birds and squirrels. Leave 1 foot of stem on the seed pod when you cut it.
Place a paper bag loosely over the seed pod and hang it in a dry, cool location. The pod will dry and drop the seeds into the bag.
Cut the dying sunflower stem at the base of the plant. These woody stems are surprisingly tough. Dig up the remaining root with a shovel and discard.
Sunflowers self-sow. If you leave the seed heads in the garden, new sunflowers will grow the following year, often in unexpected places. This may be a serendipitous occurrence or an annoyance, depending on your perspective.
Soak the sunflower seeds overnight in a bowl of water to which 1/2 cup salt has been added. Drain them and dry them with paper towels. Place them on a cookie sheet and bake them at 300 degrees Fahrenheit for 30 minutes. Store in a dry, cool container.