Sunflowers (Helianthus annuus) add boldness and rich color to cut flower arrangements. Fragrance-free, sunflowers are a good choice for indoor areas where a strong perfume can be overwhelming. For a long-lasting bouquet, give special attention to hydration, both before and after cutting your sunflowers. Using preservatives can extend the life of your flowers, which generally last a week or more at room temperature.
When and How to Cut Sunflowers
For optimum vase life, cut your sunflowers when they are almost open, with ray petals perpendicular to the flower disk. Plan a day ahead, if possible. If the ground is dry, water your sunflowers the day before you plan to cut to ensure the plants are well hydrated.
The morning you plan to cut your flowers, fill a clean bucket half full of warm water, between 100 and 110 degrees Fahrenheit. Using a clean, sharp knife, cut sunflowers in the morning before 10 a.m. Cut the stems approximately 30 inches long, and place them immediately in the bucket of water. Keep the bucket in the shade, if possible, while you cut your flowers.
Condition the Flowers
Bring the bucket of cut sunflowers inside. For optimal results, prepare another bucket of water with holding preservative. To make a holding solution, use a floral preservative containing sucrose for energy, an acidifying agent to balance the pH level and aid hydration and an antimicrobial agent, to prevent stem clogs. Mix the solution according to the manufacturer's instructions, as underdosing flowers results in little or no increase in vase life, and overdosing causes damage to flowers.
Remove any leaves from the lower portion of the stems and recut the sunflower stems under water, making an angled cut with a sharp knife. Place the stems immediately in the fresh solution. Place the bucket of flowers in a cool location for at least one to several hours before arranging flowers in a vase.
Arrange the Sunflowers
Fill a vase or other clean container one-half full of the same type of holding solution used during the conditioning period. Arrange sunflowers, making certain no leaves will be below the water line after the vase is filled with water. After the flowers are arranged, finish filling the vase with holding solution.
Keep Sunflowers Fresh
Keep your sunflowers fresh longer by recutting stems and putting them in fresh holding solution every two days. Cut the stems under water to prevent air bubbles from entering the stem's vascular system. Keep the stems in water while you empty the vase, clean it and add fresh holding solution. Return the flowers to the vase and finish filling the vase with holding solution. Keep flowers out of direct sunlight and away from drafts, which can dehydrate flowers and cause them to wilt.