Sunflower (Mammoth)

📖 About This Plant

Sunflower (Mammoth) is the giant of the sunflower world, capable of reaching 8–12 feet tall with a single head spanning 12–24 inches across — large enough to produce a cup or more of seeds per plant. The Mammoth is not just ornamental; it's a functional food crop, producing large, plump seeds with a thin shell ideal for roasting and snacking. The towering plants become a seasonal landmark in the garden, drawing pollinators from a wide area and providing summer birds with both nectar and a perch. Despite their imposing size, Mammoth sunflowers are among the easiest plants to grow — they are drought-tolerant once established, unfazed by poor soils, and virtually never troubled by diseases. Children especially love them for the sheer theatrical scale.

📊 Quick Facts

📅 When to Plant in Your Area

🌱 Care Tips

Direct sow Mammoth sunflower seeds outdoors after your last frost when soil has warmed to at least 50°F, planting 1 inch deep. For the largest possible heads, space plants 24–30 inches apart in full sun — crowded sunflowers grow tall but thin, with smaller heads and weaker stems prone to wind damage. Work a handful of balanced slow-release fertilizer into the soil at planting; heavy feeders benefit from a side-dressing of balanced fertilizer once the plant reaches 3 feet. Water at the root zone, not on the head or foliage. Mammoth sunflowers in exposed locations may need staking with a bamboo pole tied loosely to the stem once they reach 4–5 feet — gusty weather can snap large plants. Watch for sunflower moth larvae that tunnel into developing seed heads in late summer; a light application of Bt spray at first sign is effective. Harvest seeds when the back of the head turns yellow-brown and seeds feel firm — hang upside down to dry completely before hulling or roasting.

🤝 Companion Plants

These plants grow well alongside Sunflower:

🌿 Related Flower

More flower that grow in similar conditions:

❓ Frequently Asked Questions