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 10 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.

Remember, when gardening in hot climates like the low desert of Arizona, timing is critical. 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.

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). If you live in a different area, you may need to adjust your dates.

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.

Disclaimer: this post contains affiliate links. See my disclosure policy for more information.

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

Ranunculus is simple to grow and their blooms are unbelievable. This stunning flower is easily my favorite cool-season flower for mild winters.

How to plant ranunculus

Ranunculus is grown from corms. Order corms early to have them in time for fall planting.
Ranunculus grows best in rich, healthy, well-draining soil with plenty of sunlight.
Plant corms 2-3 inches deep and about 6 inches apart.

When to plant 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 danger of frost is passed.
In the low desert of Arizona, plant ranunculus corms from October – November and again from February – March.
Blooms from February through early May.

Tips for growing ranunculus

Look for large corms, they will have larger blooms.
Soak corms before planting.
Corms may be dug up at the end of the season.

Good to know when growing ranunculus

All parts of ranunculus are poisonous when ingested.
Deadheading plants encourages more blooms.
Hot temperatures cause blooms to stop.

Looking for more information? Read this blog post or watch this video.

10 Flowers that Love Mild Winters #2: Lobelia

I’m a sucker for bright blue lobelia flowers. I love putting them along the edge of beds or containers. They trail over and add a bright pop of color.

How to plant lobelia

You can grow lobelia from seed, but I have had the best luck with young transplants.

When to plant lobelia

Plant lobelia from late September – December in the low desert. Do not plant if temperatures are still hot.
Blooms from March through early June.

Tips for growing lobelia

Prefers part sun.
Needs regular water.
Wait until hot temperatures subside to plant transplants.

Good to know when growing lobelia

Plant at the edge of containers.
Beautiful when paired with blue salvia.
Abundant blooms.
Tolerates neglect.

Cool-Season Flowers That Love Mild Winters #3: Sweet Peas

How to plant sweet peas

Sweet peas grow best from seeds. Click here for sweet pea seeds.
Plant in areas with full sun to shade.
Plant seeds 1 inch deep, 2-3 inches apart. Thin to about 5 inches apart when seedlings are 2-3 inches tall.

When to plant 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.

Tips for growing sweet peas

Put trellises in place before you plant so as not to disturb the roots.
Once blooms begin, harvest at least every other day to encourage blooming.

Good to know when growing sweet peas

Unharvested blooms will develop seed pods and blooms will stop. Save seeds to plant the following season.

Looking for more information about how to grow sweet peas? Read this blog post.

Cool-Season Flowers That Love Mild Winters #4: Delphinium (Larkspur)

How to plant delphinium (larkspur)

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

When to plant delphinium (larkspur)

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.

Tips for growing delphinium (larkspur)

Seeds may be difficult to germinate. Freeze seeds for a week or so before planting to encourage germination.
Harvest larkspur when about 1/3 of the blooms are open for the longest vase life.

Good to know when growing delphinium (larkspur)

Wildflower; reseeds easily.
Extremely cold-tolerant.
Read this article for more information about how to grow wildflowers.

Cool-Season Flowers That Love Mild Winters #5: Foxglove

How to plant foxglove

Can be difficult to start from seed – plant transplants for best results.
Prefers part sun; needs regular water.

When to plant foxglove

Plant from September through October.
Blooms from March through May.

Tips for growing foxglove

Choose an area with afternoon shade.

Good to know when growing foxglove

Can be difficult to grow.
All parts of the plant are poisonous; dispose of in trash not compost.
Good cut flower; harvest when just a few bottom blossoms are open.
Attracts hummingbirds.

10 Flowers that Love Mild Winters #6: Poppies

How to plant poppies

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.

When to plant poppies

Plant seeds from October through February.
Blooms from March through early May.

Tips for growing poppies

Thin seedlings to 6” to 9” apart (depending on the variety) to maximize air circulation and reduce powdery mildew.
The larger-stemmed varieties of poppies make a beautiful cut flower. Cut stems nearly down to the ground just as blooms begins to crack open for cut flowers.

Good to know when growing poppies

Poppies reseed easily year after year.
Save seeds at the end of the season from your favorite blooms.

Looking for more information about how to grow poppies? Read this blog post.

Cool-Season Flowers That Love Mild Winters #7: Nasturtium

How to plant nasturtiums

Nasturtium grows best from seed. Click here for nasturtium seeds.
Plant seeds ½ to 1 inch deep and 5-6 inches apart.

When to plant nasturtiums

Plant nasturtium seeds from October through January.
Nasturtium blooms from February through May.

Tips for growing nasturtiums

Nasturtiums prefer cooler weather, so in warm climates grow plants in the shade to prolong their growing season.
If you want an abundance of flowers, do not fertilize nasturtiums. Nutrient-rich soil grows plenty of green leaves, but not as many blooms.

Good to know when growing nasturtiums

The flowers, leaves, and stems of nasturtiums are all edible.
Each flower sets several seeds, and nasturtiums will self-seed easily year after year.

Looking for more information about how to grow nasturtiums? Read this blog post.

Cool-Season Flowers That Love Mild Winters #8: Calendula

How to plant calendula

Calendula grows best from seed. Click here to buy calendula seeds.
You can use transplants. When choosing transplants, smaller is usually better.
Plant calendula seeds ¼ inch deep.
Thin seedlings to 6 to 12 inches apart.

When to plant calendula

In hot summer areas like Arizona, calendula grows best throughout the cooler months of late fall and spring.
In the low desert of Arizona, plant calendula seeds and transplants beginning in late September through November.
Calendula blooms in Arizona from December through May.

Tips for growing calendula

Succession plant calendula seeds every 2 or 3 weeks for a continual harvest.
Calendula needs regular water; do not let the plant dry out.
Keep flowers cut back to encourage more blooms.

Good to know when growing calendula

Harvest calendula blooms when petals begin to open.
Calendula petals are edible.
The entire calendula flower is used in healing skin ointments, salves, oils, and teas.

Looking for more information about how to grow calendula? Read this blog post.

10 Flowers that Love Mild Winters #9: Snapdragon

How to plant snapdragons

I usually purchase snapdragons as transplants.
You can also start seeds indoors. Do not cover seed with soil, it needs light to sprout. Click here for snapdragon seeds.