A sunflower bouquet adds a bright splash of colour to occasions from a country wedding to an urban neighbourhood picnic. Use several sunflower varieties in a single bouquet for their different hues and dimension, or stick with the classic look of a single variety. When you grow your own sunflowers in the garden, pick them in the early morning so your bouquet will be at the peak of freshness. Pick up flowers from the florist no sooner than a day before your event, and keep them in a cool room until it is time to assemble the bouquet.
Select freshly picked, non-pollen-producing sunflowers with tight centres and no wilted petals. Check for strong, sturdy stems, and choose only those that are 1 foot long or longer.
Strip the leaves off each sunflower stem, leaving only the top three to five leaves intact. Cut 1 inch off the bottom of each stem with sharp pruners.
Mix 1 tbsp floral preservative powder in a vase filled with water. Set the sunflowers in the vase, and leave them sitting in a cool room or shaded space for at least an hour to completely hydrate.
Remove the sunflowers from the vase, and gently dab the stems with a paper towel to absorb excess water. Lay the flowers side by side, faceup on a counter or table with the bottoms of the stems aligned.
Pick up the three flowers with the longest stems, and hold them in one hand with each flower's face pointing a separate direction. Add the remaining flowers, one at a time, to the bouquet in your hand. Orient each flower's face away from the centre three flowers.
Place a rubber band around the stems, 6 to 8 inches down from the flowers. Set the assembled bouquet in an empty vase to avoid crushing the flowers.
Wrap a 3-foot length of ribbon around the sunflower stems, covering the rubber band, and tie the ribbon into a bow. Cut the ribbon ends at a 45-degree angle with sharp scissors.