12 Best Flower Seeds to Sow in September

As summer fades, many gardeners start to wonder how they can keep their gardens vibrant through the fall. Well, I have good news! If you’re anything like me, you might find yourself wondering how to keep your garden vibrant and alive as summer fades away. Well, guess what? September is actually one of the best months to plant flowers! That’s right—you don’t have to say goodbye to your blooming beauties just yet. Let’s explore the best flower seeds to sow in September!

Why September is the Perfect Month for Planting Flowers

You might be thinking, “Isn’t it a little late in the year to be planting flowers?” Not at all! September is a prime time for planting, and here’s why.

First off, the cooler temperatures are a blessing for new plants. Unlike the scorching heat of summer, the milder September weather allows flowers to settle into their new homes without the stress of intense sun. Plus, the soil is still warm from the summer, which encourages strong root growth. Strong roots mean happy, healthy plants that will reward you with gorgeous blooms.

Another perk of planting in September is the extended growing season. Many flowers planted now will continue to bloom well into the fall, giving you weeks—if not months—of added color and beauty. It’s like hitting the garden jackpot!

Top Flowers to Plant in September Fall Garden

So, what should you plant? Here are some of my favorite flowers that thrive when planted in September:

Chrysanthemums

Chrysanthemums, commonly known as “mums,” are the quintessential fall flower, offering a wide range of colors that brighten up any autumn garden. These hardy perennials are easy to care for and can provide blooms from late summer through to the first frost.

• Light Requirement: Full sun to partial shade.
• Temperature: Cooler fall temperatures are ideal; frost-resistant.
• Humidity: Low to moderate.
• USDA Zones: 5-9.
• Special Notes: Mums are great for borders, pots, and as cut flowers. They are also deer-resistant.

Pansies

Pansies are a gardener’s favorite for their vibrant colors and ability to bloom in cool weather. These flowers can add a cheerful touch to your garden from fall through early spring.

• Light Requirement: Full sun to partial shade.
• Temperature: Cool temperatures; frost-tolerant.
• Humidity: Moderate humidity levels are best.
• USDA Zones: 4-8.
• Special Notes: Pansies are edible and make a lovely addition to salads. They also work well in containers and hanging baskets.

Marigolds

Marigolds are easy-to-grow annuals that add a burst of color to your garden. They are also known for their pest-repellent properties, making them a functional and beautiful addition to any space.

• Light Requirement: Full sun.
• Temperature: Warm temperatures, but they can tolerate cooler fall weather.
• Humidity: Low to moderate.
• USDA Zones: 2-11.
• Special Notes: Marigolds are often used as companion plants in vegetable gardens to deter pests.

Snapdragons

Snapdragons are tall, spiky flowers that add height and structure to your garden. They are known for their vibrant colors and unique flower shapes, which resemble the face of a dragon.

• Light Requirement: Full sun.
• Temperature: Cool to mild temperatures; frost-tolerant.
• Humidity: Low to moderate.
• USDA Zones: 6-11.
• Special Notes: Snapdragons can be grown as short-lived perennials in warmer zones. Deadhead regularly to prolong blooming.

Asters

Asters are classic fall flowers known for their daisy-like appearance and vibrant purple or blue petals. They are essential for adding color late in the season when many other flowers have faded.

• Light Requirement: Full sun to partial shade.
• Temperature: Cooler temperatures are ideal; frost-tolerant.
• Humidity: Low to moderate.
• USDA Zones: 4-8.
• Special Notes: Asters attract bees and butterflies, making them excellent for pollinator gardens.

Cornflowers (Centaurea cyanus)

Cornflowers, also known as bachelor’s buttons, are true blue flowers that are hardy and easy to grow. They are perfect for adding a splash of color with minimal care and thrive in various climates.

• Light Requirement: Full sun.
• Temperature: Prefers cooler temperatures; frost-resistant.
• Humidity: Low to moderate.
• USDA Zones: 2-11.
• Special Notes: Cornflowers are excellent for cutting and attract pollinators like bees and butterflies.

Scabiosa (Pincushion Flowers)

Scabiosa, or pincushion flowers, are delicate-looking but tough plants that offer long-lasting blooms. They are particularly attractive to pollinators and are perfect for cutting gardens.

• Light Requirement: Full sun to partial shade.
• Temperature: Mild to cool temperatures; frost-tolerant.
• Humidity: Low to moderate.
• USDA Zones: 3-7.
• Special Notes: Scabiosa blooms from late spring to early fall and requires minimal care.

Douglas Meadowfoam (Limnanthes douglasii)

Douglas Meadowfoam, also known as the poached egg plant, is a charming ground cover with yellow-centered white flowers. It’s ideal for attracting pollinators and suppressing weeds.

• Light Requirement: Full sun to partial shade.
• Temperature: Cool, moist conditions are preferred.
• Humidity: Moderate to high.
• USDA Zones: 4-8.
• Special Notes: This plant is excellent for ground cover and naturalizing in garden beds.

Cerinthe (Blue Shrimp Plant)

Cerinthe, with its unusual purple-blue flowers, is a standout in any garden. It’s particularly valued for its ability to attract pollinators and its vibrant color, which adds a unique touch to floral arrangements.

• Light Requirement: Full sun to partial shade.
• Temperature: Mild to warm temperatures; protect from frost.
• Humidity: Moderate.
• USDA Zones: 7-10.
• Special Notes: Both the leaves and flowers are edible, adding a mild, honey-like flavor to dishes.

Nigella (Love in a Mist)

Nigella, or love in a mist, is a charming plant with delicate, misty foliage and striking blue or white flowers. It’s easy to grow and adds a whimsical touch to any garden.

• Light Requirement: Full sun.
• Temperature: Prefers cool weather; frost-tolerant.
• Humidity: Low to moderate.
• USDA Zones: 2-11.
• Special Notes: Nigella has a short flowering period, but its seed pods are excellent for dried arrangements.

Sea Holly (Eryngium)

Sea Holly is an architectural plant known for its striking blue, spiky flowers. It adds structure and interest to gardens, particularly in the late summer and fall.

• Light Requirement: Full sun.
• Temperature: Prefers cooler climates; drought-tolerant.
• Humidity: Low humidity is ideal.
• USDA Zones: 4-9.
• Special Notes: Sea Holly is perfect for dried flowers and attracts pollinators. It thrives in poor, sandy soils.

Poppies

Poppies are iconic flowers that come in a variety of colors and types, from the vibrant California poppy to the delicate Icelandic poppy. They are easy to grow and add a bold splash of color to any garden.

• Light Requirement: Full sun.
• Temperature: Prefers cooler temperatures; frost-tolerant.
• Humidity: Low humidity is best.
• USDA Zones: 2-10, depending on the variety.
• Special Notes: Poppies are excellent for naturalizing in garden beds and are often used in remembrance ceremonies due to their symbolic nature.

Planting Tips for September Flowers

Now that you’ve got your list of flowers, let’s talk about how to plant them for the best results.

• Prepare the Soil: Before you start digging, make sure your soil is ready. Loosen the soil to a depth of about 12 inches and mix in some compost or organic matter. This will give your flowers a nutrient-rich environment to grow in.
• Watering: Newly planted flowers need plenty of water to help them establish. Water them deeply after planting, and then keep the soil consistently moist until you see new growth. Just be careful not to overwater, especially if the weather is cool.
• Spacing: Give your flowers enough space to grow. Crowding can lead to poor air circulation and increase the risk of disease. Follow the spacing recommendations on your plant labels for the best results.
• Mulching: A layer of mulch around your flowers will help retain moisture, suppress weeds, and regulate soil temperature. Plus, it just makes everything look neat and tidy!

READ: Does Blue Daisy Exist?

Caring for Your September-Planted Flowers

Your flowers are in the ground, and they’re looking great. Now, how do you keep them that way?

• Soil Moisture: As the weather cools, it’s important to maintain consistent soil moisture. Check your soil regularly—if it feels dry an inch or two below the surface, it’s time to water.
• Deadheading: To keep your flowers blooming as long as possible, make sure to deadhead (remove) spent blooms. This encourages the plant to produce more flowers rather than putting energy into seed production.
• Frost Protection: Depending on where you live, you might get an early frost in October or November. If frost is in the forecast, cover your flowers with a light cloth or garden fabric to protect them overnight.

Preparing Your Garden for Winter After Fall Blooms

As fall winds down and your flowers begin to fade, it’s time to start thinking about winter preparations. But don’t worry—there’s still plenty you can do to keep your garden looking great.

• Composting: After your flowers have finished blooming, you can cut them back and add the clippings to your compost pile. This not only tidies up your garden but also creates valuable compost for next spring.
• Soil Conditioning: Fall is a great time to improve your soil. Consider adding a layer of compost or organic matter to your garden beds. This will break down over the winter, enriching your soil for next year’s planting.
• Winter Interest: Finally, consider adding some plants that will bring interest to your garden through the winter months. Evergreen shrubs, ornamental grasses, and plants with colorful stems or berries can keep your garden looking lively even in the depths of winter.

READ: Do Azaleas Look like Rhododendrons?

Conclusion

September is the perfect time to refresh your garden and extend the blooming season. By choosing the right flowers and following these planting and care tips, you can enjoy a vibrant, colorful garden well into the fall. So why not take advantage of this golden opportunity? Grab your gardening gloves, head to your local nursery, and let’s make this autumn your garden’s best season yet!

Happy planting!