Mammoth: Their wooly namesakes may have gone extinct, but mammoth sunflowers grow just as tall as the prehistoric beasts, reaching a height of 9 to 12 feet (2. 7 to 3. 7 meters). Autumn Beauty: This variety produces large flowers that grow up to six inches in diameter. It gets its name from the fall-like spectrum of flowers it produces. Bronze and mahogany flowers are not uncommon on these large stalks that can reach seven feet. Sunbeam: Sunbeam is a medium-sized variety, standing at about five feet tall and producing flowers about five inches in diameter. Sunbeam flower petals are long and asymmetrical, and the flower center is often yellow, making for a dramatic addition to any bouquet. Teddy Bear: This miniature variety caps out at three feet tall and is perfect if you are tight on space in your garden.
If possible, it is also best to shield sunflowers from the wind. Plant sunflower seeds along a fence, the side of a house, or behind a row of sturdy trees. If possible, plant your sunflowers on the north side of your garden. This prevents the large sunflower stalks from shading other plants in your garden.
Your local agricultural extension office should have soil testing forms, bags, and instructions available. After making adjustments to the soil, test the pH level again. If the pH level is below 6. 0, enrich the soil using acid compost or planting mix. If the soil pH is above 7. 5, mix in granular sulfur to lower the pH level.
Be sure that your plot has proper drainage, or opt to build a simple planter box instead. If necessary, build a raised garden box out of cedar boards, which come in 8-foot lengths. Cedar is a good choice for a garden bed because it won’t rot when exposed to water. [1] X Research source
For large sunflower types, allow 18 inches (45. 7 cm) of space between seeds. For medium-sized sunflower types, allow 12 inches (30. 5 cm) of space between seeds.
If you’re growing sunflowers as a seed crop or to display in flower shows, mulch with 1. 5 inches (4 cm) of well-rotted manure or compost once the plants are 20 in. (0. 5 m) tall.
Sunflowers also can contract mildew and rust. If either of these issues occurs, spray your flowers with a fungicide. Deer and birds are also known to eat sunflower plants. Put up netting to prevent these animals from destroying your plants.
For delicious roasted seeds, soak overnight in water and salt. Then drain and place on a baking sheet. Roast in a low-heat oven (between 200°F and 250°F / 90 to 120ºC) until slightly browned.
