Mammoth Grey Stripe Sunflower Seeds

Mammoth Grey Stripe Sunflower is a classic, towering sunflower that brings big height and bold blooms to any sunny garden space. This variety is easy to grow, performs well even in less-than-perfect soil, and produces impressive flower heads that make a strong statement along fences, garden borders, and backdrops. With its single-stem habit, it’s also a great option for cut flower use when you want one big, showy bloom per plant.

Seed Packet Details

Packet Size: Standard home-garden seed packet (Approx. 50 seeds)

Packed with care and shipped from Kentucky.

Product Details

Botanical Name: Helianthus annuus
Variety: Mammoth Grey Stripe Sunflower
Seed Type: Open-pollinated
Life Cycle: Annual

What to Expect

Mammoth Grey Stripe grows into a tall, sturdy sunflower reaching roughly 8–12 feet in height under good conditions. Plants produce large blooms, and the single-stem growth habit typically means one main flower per plant, making it a solid choice for cut flower gardens and bold landscape impact. Once established, it’s a dependable performer with simple, low-fuss care in full sun.

Growing Basics

Sun: Full sun
Plant Height / Spread: 8–12 feet
Sow Method: Direct sow
Sow Depth: 1/2 inch
Days to Maturity: Approximately 55 days
Growing Conditions: Warm weather; adaptable to average or poorer soils

Growing Guide: Sunflowers

Overview

Sunflowers are warm-season annuals prized for fast growth, strong stems, and bright blooms. Mammoth Grey Stripe is known for impressive height and big flower heads, making it a favorite for garden backdrops and sunny statement plantings.

Before Planting

Choose a sunny location with room for tall growth. Sunflowers perform best where they won’t be shaded, and they benefit from a spot that’s somewhat protected from strong wind.

Planting

Direct sow after the danger of frost has passed and soil has warmed. Sow seeds about 1/2 inch deep and keep the area weed-free while seedlings establish.

Watering

Water regularly during early growth to establish strong roots. Once established, sunflowers are typically more forgiving with moisture, though consistent watering supports stronger stems and better bloom development.

Fertilizing

Sunflowers often grow well in average soil. If your soil is very poor, mixing in compost before planting can help support taller plants and larger blooms.

Days to Maturity

Mammoth Grey Stripe typically begins flowering in about 55 days, depending on temperatures and growing conditions.

Harvesting

For cut flower use, harvest when the bloom is beginning to open and petals are just starting to lift. Place stems in fresh water immediately for best vase life.

Growing Tips

Because this variety gets tall, consider staking in windy areas. Planting along a fence line can add support and keep tall stalks upright through summer storms.