Growing flowers from seeds is one of the easiest and most affordable ways to create a colorful summer garden. Many summer flowers grow quickly, require minimal care, and bloom within weeks, making them perfect for beginners and home gardeners.

In this guide, you’ll discover the fastest growing summer flowers from seeds, along with simple growing tips to help you get the best results.

1. Zinnia – Quick & Colorful Blooms

Zinnias are one of the fastest growing summer flowers. They germinate quickly and produce bright, long-lasting blooms.

Why grow zinnias:

• Germinate in 5–7 days
• Bloom in 6–8 weeks
• Available in many colors

Growing tip:
Plant in full sunlight and water moderately for best flowering.

2. Marigold – Easy & Low Maintenance

Marigolds are extremely popular for summer gardens because they grow fast and protect other plants from pests.

Why grow marigolds:

• Germination in 5–7 days
• Blooms in 6–7 weeks
• Pest-resistant plant

Growing tip:
Remove dead flowers regularly to encourage more blooms.

3. Sunflower – Tall & Fast Growing Beauty

Sunflowers grow rapidly and add height and brightness to any garden.

Why grow sunflowers:

• Germinates in 7–10 days
• Blooms in 8–10 weeks
• Grows very tall

Growing tip:
Plant in deep soil with full sun exposure.

4. Cosmos – Delicate Summer Flower

Cosmos are lightweight, airy flowers that grow quickly and require little care.

Why grow cosmos:

• Germinates in 7–10 days
• Blooms in 7–9 weeks
• Drought tolerant

Growing tip:
Avoid overwatering; they prefer slightly dry soil.

5. Portulaca (Moss Rose) – Heat Resistant Flower

Portulaca is perfect for hot summer climates and grows extremely fast.

Why grow portulaca:

• Germination in 5–7 days
• Blooms in 6–8 weeks
• Thrives in extreme heat

Growing tip:
Plant in sandy, well-drained soil for best growth.

6. Calendula – Bright Medicinal Flower

Calendula grows quickly and is known for both beauty and medicinal use.

Why grow calendula:

• Germinates in 6–8 days
• Blooms in 7–8 weeks
• Attracts pollinators

Growing tip:
Keep soil slightly moist for continuous flowering.

7. Nasturtium – Edible Flower Plant

Nasturtiums are fast-growing flowers with edible leaves and blooms.

Why grow nasturtiums:

• Germinates in 7–10 days
• Blooms in 6–8 weeks
• Easy to grow in poor soil

Growing tip:
Avoid rich soil; too much fertilizer reduces flowers.

8. Alyssum – Sweet Fragrance Flower

Alyssum produces small, fragrant flowers that spread quickly.

Why grow alyssum:

• Germinates in 5–7 days
• Blooms in 6–7 weeks
• Great ground cover

Growing tip:
Trim lightly after first bloom for repeat flowering.

9. Petunia – Popular Hanging Flower

Petunias grow fast and are perfect for pots and hanging baskets.

Why grow petunias:

• Germination in 7–10 days
• Blooms in 7–9 weeks
• Long blooming season

Growing tip:
Provide regular sunlight and remove faded flowers.

10. Gaillardia – Drought Resistant Flower

Gaillardia is a tough summer flower that blooms continuously.

Why grow gaillardia:

• Germinates in 7–10 days
• Blooms in 8 weeks
• Heat and drought tolerant

Growing tip:
Do not overwater; thrives in dry conditions.

General Tips for Fast Flower Growth

• Use good quality seeds
• Provide 6–8 hours of sunlight daily
• Keep soil well-drained
• Water lightly but regularly
• Remove dead flowers to encourage new blooms

Conclusion

Fast growing summer flowers from seeds are perfect for creating a beautiful garden in a short time. Whether you choose zinnias, marigolds, sunflowers, or cosmos, these flowers will quickly transform your space into a colorful and lively environment.

Start planting today and enjoy a vibrant summer garden within weeks.