What are Cool Flowers, and Why to grow them?
Cool Flowers, or Cool Season Annuals, or Hardy Annuals are flowers that grow in cool or cold weather.
They don’t just survive in this weather, they thrive.
So what flowers are these?
This is very dependent on the weather where you live, your zone, but for me here in zone 5B cool season annuals extend my growing season, and give me flowers that I cannot grow in the heat of summer.
Some examples of cool season annuals are:
redbeckia
ammi/dara
bupleurum
Bells of Ireland
larkspur
Snapdragons
Poppy’s
Nigella
Sweet Peas
Just to name a few….
Larkspur in bloom
So Cool season annuals are just that…they are annuals.
They live for one growing season.
However, their growing season either starts in the fall OR very early spring.
Again, when to start these depends on your growing conditions.
So you need to check if the flower is hardy to your growing zone.
I live in zone 5b, so anything hardy to zone 5, I can start in the fall and then let it grow into a small plant, then it will freeze and be covered in snow and then you will think that it is dead.
THEN in the spring it will start to grow just at the correct time, it will take off and be much stronger, more vigorous plant then if you started it in the spring.
If the plant is not hardy to your zone, then you must plant it in the very early spring.
What is very early spring?
Well, that depends on your frost dates.
If you want to know your zone and frost dates, just google your location and check for your zone, and frost dates.
The last frost date is the last average frost that takes place in the spring.
For example in Dorr, MI where I live, my average last frost date is May 15th.
And your first frost date is the average date in the fall that your first frost comes.
Again, for me October 15th is my average first fall frost date.
Now keep in mind that this is an average date.
You can have frosts late in the spring and early in the fall, and we certainly have here in MI.
In 2020 we had a frost in the end of September and in Spring 2021 we had a killing frost Memorial Day weekend and a lot of people had to replant their gardens. Just ask my dad……sorry dad!
So for me, if I am fall planting my cool season flowers that are hardy to my zone, I would plant them in the fall in early September to get them to become baby plants before my first fall frost.
If I am very early spring planting, then I could plant in early April…or as soon as the garden can be worked.
Sometimes we still have snow in April, or the ground is frozen.
The best resource is trial and error in your garden.
While you may live in a certain zone, there are microclimates everywhere.
Certian cool flowers are more hardy than others.
For example, last spring I planted stock transplants in the beginning of April. Well, we went down to an 18 degree night, and then with in 24 hours it was in the 50’s.
These major swings in temperature are very stressful to a small transplant.
Needless to say almost all my stock transplants died.
However, my Bells of Ireland planted the same time looked great.
baby bupleurum in a Februaury thaw
This group of plants can be confusing, BUT if you time it correctly, you can get blooms earlier in the season.
Here in Michigan, June can be a month with not many annual flowers blooming as we are in a lull from spring bulbs and summer heat loving annuals.
Who can grow these? ANYONE CAN!!!
All you need is a small space and a few seeds.
Larkspur is a real favorite of mine. It is direct sown easily in the garden and then sprouts early in the spring.
Fall planted Yarrow (photo credit my 5 year old)
Fall planted Larkspur
I hope this has given you an idea of what cool flowers, or hardy annuals are, and I hope that you will consider adding them to your garden.
Email me at info@abundantbloomsflowerfarm.com and tell me your favorite cool flower!
-Ruth Ann
Are you ready to learn more and grow flowers in your backyard with your children?
You are in the right place. I have created a SUPER affordable beginners Guide so you can get started planning and growing TODAY so that you also can experience the joy of watching your children and flowers grow together just as I have.
