10 flowers to plant in September in HOT climates

By September gardeners are getting an itch to get back into the garden, especially in hot places like Arizona where summers are so long. It's still hot in September, but usually, nighttime temperatures start to go down a bit, which is a great time to start planting more flowers. These flowers can still take the heat but can provide some much-needed color in the garden.

1.) Marigolds: Marigolds are known for their bright orange and yellow blooms. They are incredibly heat-tolerant and can withstand the intense sun. Additionally, marigolds can repel pests, making them a great addition to any garden. They are a perfect addition to the fall garden with their autumnal orange and burgundy colors that they come in.

African marigolds make a large statement in the garden, and are perfect for cut florals. Pictured are coco ‘gold’ and ‘orange’

French marigolds are perfect for boards and adding into smaller sized pots. They come in orange, yellow and burgundy (pictured in bottom right).

2.)Ornamental Peppers: These plants add a splash of color with their vibrant fruits, which range from red and orange to purple and yellow. Their fruit display is the best in late summer and fall so it's a perfect time to tuck them into the garden beds or containers. Ornamental peppers are highly heat-tolerant and can handle dry conditions, making them ideal for hot climates.

3.) Celosia: I'm a HUGE celosia fan. They are one of my favorite flowers! They come in so many colors and shapes that are perfect for the fall garden. They come in colors from red, orange, pink, and yellow. They thrive in hot weather and bring a fun touch to garden beds and borders.

‘Floret celosia’

check out the Celosia growing Guide for more information.

4.) Petunias: Yes, Petunias are on this list! Petunias are typically cool-season flowers that thrive in cooler temperatures, but they can also take the heat! They do prefer cooler nighttime temperatures, so plant when nights drop to around 70 degrees or below. They are versatile flowers and come in various colors and patterns. They are relatively easy to grow and can handle the heat, making them perfect for hanging baskets, window boxes, or garden beds. Make sure to consistently fertilize them for best results.

Supertina Vista mini ‘pink star’

5.) Calibrachoa: These flowers are in the petunia family and are often referred to as "million bells". Calibrachoa produces small, petunia-like flowers that cascade beautifully over containers and hanging baskets. They love the sun and are excellent for adding a burst of color to your garden.

Potting bench filled with calibracoa for spring. If we wanted to grow for fall we would plant more oranges and red tones.

6.) Sunflowers: Sunflowers are great options as they love the heat, and bloom quickly. Make sure that there are enough days in your season before planting. Most sunflowers take 55-65 days to bloom. Some garden centers offer compact varieties that bloom all season, these would be great options for instant color. They thrive in poor soils and full sun.

Sunflower Procut ‘White Nite’

Click here for more sunflower growing tips, trick, and varieties.

7.) Zinnias: Zinnias are another great option to plant in September. If there are enough days in your season you can direct seed zinnias for fall blooms. They typically take 55-75 days to bloom. I usually get starts from the nursery to get a boost in the garden for a faster impact

Mix of Queen, Oklahoma, and Salmon zinnias.

Click here for more zinnia growing tips and varieties.

8.) Impatiens: If you live in a climate with more humidity or cooler temperatures you can plant these all summer long. These flowers seem to struggle when nighttime tempers get high, with low humidity. I like to plant them in September when temperatures are still warm, but not blistering. They thrive in full shade. They can take the morning sun when temperatures drop below 80 degrees.

9.) Coleus: Known for their stunning foliage, coleus plants are available in various patterns and colors. They prefer partial shade and can add a vibrant touch to areas that don't receive direct sunlight. Coloeus, like inpatients, sometimes struggles in the height of the summer. Replanting them in September extends their season and allows you to enjoy their beautiful foliage that is perfect for fall color.

Click here for more tips on coleus care.

10.) Begonias: Begonias are an easy shade plant that is great to plant in September. They are known for their beautiful flowers and attractive foliage, making them a great choice for adding diversity to your garden. Again like the coleus and impatents, they can struggle in the high heat of summer. Replace them in September and enjoy them all winter. Protect them from frost and bring containers inside or cover them with frost cloth.

‘Dragon Wing’ Begonia

When we are planting things in September, we typically lean toward a more Atunmal color pallet. A lot of these flowers already do so, especially the marigolds, celosia, and ornamental peppers. We typically lean toward the oranges, yellows, reds, and deep purples to bring out a beautiful sense of seasonality in the garden.

Check out the blog post fall gardening in HOT climates for more information and design tips.