Sunflower: Sow and Grow GuideUpdated 14 days ago
Sunflowers are bright, cheerful flowers that are easy to grow and add a striking presence to any garden. Here’s a concise guide to successfully sowing and growing sunflowers.
When to Sow
Sow sunflower seeds outdoors after the last frost when the soil has warmed to at least 60°F. Sunflowers can be sown every 2-3 weeks for a continuous display of blooms throughout the summer.
Outdoor Sowing
Choose a sunny location with well-drained soil. Sow seeds 1/2 inch to 1 inch deep, spacing them 6-12 inches apart, depending on the variety. Larger sunflower varieties need more space, while dwarf varieties can be planted closer together. Water gently after sowing and keep the soil consistently moist until germination, which typically takes 7-10 days.
Indoor Sowing
Sunflowers can be started indoors 2-4 weeks before the last frost to get an early start. Sow seeds in peat pots or biodegradable containers to avoid root disturbance during transplanting. Plant seeds 1/2 inch deep in a light, well-draining soil mix. Keep the soil moist and place the containers in a sunny location or under grow lights. Transplant seedlings outdoors once they have a few sets of true leaves and the danger of frost has passed.
Care and Maintenance
Sunflowers require full sun and regular watering, especially during dry spells. Water deeply to encourage strong root development but avoid waterlogging. Taller varieties may need staking to prevent them from toppling over. Fertilize sunflowers with a balanced fertilizer when the plants are about 2 feet tall to support their rapid growth.
Pests and Diseases
Sunflowers are relatively pest-resistant, but they can attract aphids and caterpillars. Manage pests with insecticidal soap or by encouraging natural predators like ladybugs. Sunflowers can be prone to fungal diseases such as downy mildew, so ensure good air circulation and avoid overhead watering.
Harvesting
For cut flowers, harvest sunflowers when the buds are just starting to open, using sharp scissors or garden shears. If harvesting seeds, wait until the back of the flower head turns brown and the seeds are plump and fully developed. Cut the flower head and allow it to dry in a warm, dry place before removing the seeds.
Garden Use
Sunflowers are versatile and can be used in garden beds, borders, or as a living screen or hedge. They are also excellent companions for crops like corn, beans, and squash. Sunflowers attract pollinators and beneficial insects, making them a valuable addition to any garden.
For further details, visit the full guide on the Botanical Interests Blog.