10 Cool-Season Flowers That Love Mild Winters

Although summers are hot in the low desert, our winters are mild. Several beautiful flowers grow well during the mild winter and bloom through early spring.

In this post, I share my ten favorite cool-season flowers that love mild winters. Keep reading to the end for my honorable mention choices for flowers that grow well during mild winters. 

Growing Tips For Low Desert Gardeners

The Low desert includes elevations below 3500 ft in the Southwest, such as the Phoenix and Tucson metro areas.

Remember, timing is critical when gardening in hot climates like the low desert of Arizona. Learning the best times to plant will help you be successful. This guide for cool-season flowers that love mild winters will help you know when to plant and whether to plant seeds or transplants.

Here are a few things to keep in mind: 

• When you plant at the correct time, seeds will sprout, and transplants will become established in the optimal conditions for each plant. 
• The planting dates listed are for the low desert of Arizona (zone 9b). You may need to adjust your dates if you live in a different area.
• And finally, don’t be afraid to start flowers from seed. Transplants aren’t always available at the best time to plant. However, use good judgment when starting from seed. If it is at the end of the planting window for that particular plant, it might be best to plant a transplant rather than start from seed.

Many spring-blooming bulbs also thrive in our mild winters—learn more in the Arizona Bulb Planting Guide.

Not sure what to plant or how to grow it? The Ultimate Plant Index covers everything from ranunculus and poppies to basil and spinach—organized A–Z for easy browsing. It’s your go-to resource when you’re planning your garden or seeking care tips.

10 Cool-Season Flowers That Love Mild Winters #1: Ranunculus

In zones 7 and warmer, there are two planting windows — late fall and again in late winter or early spring. For zones cooler than zone 7, plant in the spring after the danger of frost is passed. 

When to plant ranunculus in Arizona: October – November & February – March

• Look for large corms; they will have larger blooms.
• Soak corms before planting.
• Corms may be dug up at the end of the season.
• Looking for more information? Read how to grow ranunculus or watch on youtube best tips for growing ranunculus. 

#2: Lobelia

Start seeds indoors: July – October

Plant transplants outside: September 15 – December. Do not plant if temperatures remain hot. 

Blooms from March through early June

• Plant at the edge of containers.
• Beautiful when paired with blue salvia.
• Abundant blooms.
• Tolerates neglect.
• Learn how to grow lobelia in this blog post.

The Perpetual Annual Flower Planting Calendar, available in my shop, helps you learn when to plant flowers in the low desert of Arizona and whether to plant seeds or transplants.

#3: Sweet Peas

In mild winter areas (zone 8-10) like the low desert of Arizona, plant in the fall from October through February.

Blooms from February through early May.

• Sweet peas grow best from seeds. Click here for sweet pea seeds. 
• Plant in areas with full sun to shade.
• Put trellises in place before you plant so as not to disturb the roots. 
• Learn more about how to grow sweet peas.

#4: Delphinium (Larkspur)

Larkspur grows best from seeds started directly in the garden. Click here for larkspur seeds.

• In mild winter areas (zone 8-10) like the low desert of Arizona, plant in the fall from late September through November.
• Blooms from March through May.
• Seeds may be difficult to germinate. Freeze seeds for a week or so before planting to encourage germination.

#5: Foxglove

Start seeds indoors: July – August

Plant transplants outside: September – October

Blooms from: March through May.

• Can be difficult to start from seed; plant transplants for best results. Prefers part sun; needs regular water.
• Good cut flower; harvest when just a few bottom blossoms are open.
• Attracts hummingbirds.
• Read this article for more information about how to grow foxglove.

#6: Poppies

Plant seeds from October through December.

Blooms from March through early May.

• Poppies grow best from seed. Click here for poppy seeds. 
• Direct sow poppy seeds in the garden. Push poppy seeds firmly into the soil.
• Poppies grow well in containers.
• Learn more about how to grow poppies. 

#7: Nasturtium

Plant nasturtium seeds from October through January.

Nasturtium blooms from February through May.

• Nasturtium grows best from seed. Click here for nasturtium seeds. 
• Plant seeds ½ to 1 inch deep and 5-6 inches apart.
• If you want an abundance of flowers, do not fertilize nasturtiums. Nutrient-rich soil grows plenty of green leaves but not as many blooms.
• Learn how to grow nasturtiums.

#8: Calendula

Start calendula seeds indoors: August – September
Plant seeds or transplants outside: September 15 – November

Calendula blooms in Arizona from December through May.  

• Succession plant calendula seeds every 2 or 3 weeks for a continual harvest. Learn more about succession planting in this guide.
• Calendula needs regular water; do not let the plant dry out. 
• Keep flowers cut back to encourage more blooms. 
• Learn how to grow calendula.

#9: Snapdragons

Start seeds indoors: June – December
Plant transplants outside: September 15 – February 15

Blooms from November through early May.

• Snapdragons are readily available as transplants. 
• You can also start seeds indoors.  Do not cover the seed with soil. It needs light to sprout. Click here for snapdragon seeds.
• Support large varieties with netting for straight stems. Learn how to use and install trellis netting for cut flowers.
• Cut the central stem back to ground level to encourage branching. 
• Keep deadheaded to encourage blooms.

#10: Bachelor Buttons (Cornflower)

Plant seeds in your garden from late September through November.

Blooms from February through June.

• Bachelor buttons grow best from seed. Click here for bachelor button seeds.
• Plant bachelor button seeds directly in the garden. Cover lightly with soil. 
• Cornflowers are edible. Learn how to grow and use edible flowers.
• Learn how to grow bachelor buttons (cornflower).

Other cool-season flowers that love mild winters:

Did I forget any of your favorite cool-season flowers that love mild winters? Let me know in the comments what your favorites are. If you’re looking for a tall, elegant flower to add to your cool-season garden, don’t miss how to grow campanula (canterbury bells).