Key Points
- Late Summer and early Fall, such as September, is the best time to plant chrysanthemums, which are hardy perennials that will grow back each and every year with the proper care.
- Peonies are also perennials, so after you plant them once in September, they’ll come back year after year with the proper care.
- Zinnias are annuals — but you’ll only need to buy seeds once, as you can harvest and preserve seeds from these flowers the first year.
Just because the summer’s heat is finally starting to subside doesn’t mean you have to do away with the colorful blooms you’ve come to love in your yard. There are plenty of ways to keep your garden thriving in the cooler months of the year, including considering these flowers to plant in September. From early winter blooms to sowed seeds for spring, these are the top flowers to look into planting this September for months’ worth of color.

What’s the Difference Between Perennials and Annuals?
Perennials regrow every Spring — lasting year after year — while annuals only live for one growing season, then die. Because perennials usually have a shorter blooming period, experienced gardeners like to plant some of both to ensure a continuously blooming display. Some annuals, like zinnias, produce seeds that are easy to harvest for next year’s planting.
1. Chrysanthemums
Few plants represent the Fall the way chrysanthemums, more commonly known as “mums,” do. These full blooms come in a range of autumn shades, from bright yellows to oranges to reds. As a result, they pair perfectly with the falling leaves of September.
Most often, you’ll find mums available in the latter months of Fall, such as October or November. However, the best time to plant these flowers is late summer and early fall, such as September. This is because chrysanthemums are actually hardy perennials that will grow back each and every year with the proper care. However, they need time to establish their root systems and grow healthy to survive the colder Winter months.
As a result, while you won’t want to plant seeds in September, you can certainly plant already-grown chrysanthemums at this time for year-round warm blooms.

Chrysanthemums are perennials best planted in early Fall.
©Elan Havrilyuk/Shutterstock.com
2. Chamomile
Chamomile may be an herb, but it’s actually a popular flower to plant in September. This is because not only does it sport pretty white blooms that resemble small daisies, but it can also be used around the house. Chamomile tea, after all, offers a wide variety of benefits.
You’ll need to start your chamomile seeds at least six weeks before the first frost of the year. Then, after they germinate, you’ll need to take care of them throughout Autumn and Winter to enjoy the small flowers that come from this amazing herb.

Chamomiles offer a wide range of benefits.
©Shan 16899/Shutterstock.com
3. Asters
Asters are perennial flowers that grow best in full sun. They also happen to be one of the best flowers to plant in September. They do best with well-drained soil that is watered consistently.
Unlike many other types of flowers, asters do well in Summer’s heat. They’re rather hardy, and they can last up until the first frost of the year. As a result, already-grown flowers can be planted in September and then tended throughout the winter. This results in a Fall’s worth of color and prepares the plants to bloom all next Summer.

Asters need to be watered consistently.
©Klever_ok/Shutterstock.com
4. Peonies
While it seems that Spring is the best time to plant flowers, that isn’t always the case. In fact, some flowers, like peonies, actually do better when planted in the Fall. If you were to plant peonies in early spring, it could take longer for their beautiful blooms to develop and blossom.
These garden classics are also perennials, so after you plant them once in September, they’ll come back year after year with the proper care.

Peonies do better when planted in the Fall.
©Fusionstudio/Shutterstock.com
5. Zinnias
One of the most popular garden flowers around, zinnias are among the best flowers to plant in September. They come in a wide variety of colors, and their tall stalks make it nearly impossible to miss these beautiful blooms in the garden. They’re also key in attracting pollinators at the end of the season.
However, zinnias aren’t perennials, unlike most of the plants on this list. Instead, they’re annuals, meaning you’ll need to replant them each year to enjoy these bright flowers. Thankfully, you’ll only need to buy seeds once, as you can harvest and preserve seeds from your flowers the first year.

Zinnias are annuals that come in various colors.
©Nadya So/Shutterstock.com
Summary of 5 Flowers to Plant in September
Flower | Traits | |
---|---|---|
1 | Chrysanthemums | Also called “mums;” full-bloom in October to November; Fall colors; hearty perennials |
2 | Chamomile | Herbal blooming plant; thrives when planted in September |
3 | Asters | Thrive in well-drained, watered soil; fare well in summer up through first frost; perennials |
4 | Peonies | Fair better in Fall; perennials |
5 | Zinnias | Variety of colors; tall stalks; annuals — not perennials |
The photo featured at the top of this post is © Klever_ok/Shutterstock.com
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