Feverfew, Rocket Snapdragons, Delphinium and Yarrow are perennial and return yearly

gardening cool flowers

Flower seedlings that were started inside and began their hardening off process March 31

cool flowers

Seedlings during the hardening off process covered in snow then totally happy afterward.

cool flowers

"Cool Flowers" by Lisa Mason Ziegler book

Cool Flowers

In warming weather when we feel the whispers of spring... Gardeners just want to get the season started!

The winters are always long enough for us to be excited for the warmer weather seasons ahead.

Sadly we know it's just too early to tackle many garden tasks. Of course, planting annuals is one of those things that needs to wait until after our last frost date. Maybe later... Just to be safe.

Or does it?

Typically the term "annuals" makes us think of frost-sensitive tender plants that complete their life cycle in one year. The ones we need to plant every year if we want to enjoy them in our garden. The ones that will fail to thrive or maybe just disappear altogether if the air or soil temperatures are too cool when they are planted. (Peppers, tomatoes, basil, impatiens, petunias - we're looking at you.)

The thing is those tender plants are not "Cool Flowers." This other kind of plant is "cool" partly because they're interesting and well-liked, of course. Plus they're cool because they prefer (and even thrive) in cool weather! Some of these annual plant seeds and seedlings can go outside WEEKS before our average last frost date. Some particularly hardy varieties can even overwinter here in zone 6.

It might be surprising that if these plants aren't planted outside until after our average last frost date (May 15 locally) they may underperform, struggle or even just stall out until cooler temperatures return in the fall.

Similarly to cool season food crops like lettuce, spinach, kale and cilantro, before you know this nugget of information you may wonder why these plants don't thrive in summer when plants are supposed to be growing 'round here. The fact is no amount of water, sun, shade, fertilizer or magic will make them happy if it's too warm.

Cool flowers examples are pansies, sweet peas, larkspur, nigella, calendula, poppies, some varieties of snapdragons and there are more. Some are best started inside, hardened off, then planted outside when it's still sweater weather. If this is new to you it can take quite a leap of faith to let the frost or even snow collect on those seedlings, but it doesn't bother them a bit. I remember sadly saying "goodbye" and "I'm sorry" to a mushy-looking, must-be-frozen-to-death pansy in the morning only to find it looking spry, happy and healthy again by lunch time.

Other plants only want to be direct-sown in the soil where they will grow. So how do you know which seeds to plant where and when? How far into the soil should they be placed? Or do they need to be sprinkled on top of the soil and left alone? For germination: some need light, some need darkness, some need warm, others want it cool. It seems they all have their own special needs and quirks. Don't we all?

It all comes down to the type of seed combined with your USDA hardiness growing zone. (Locally zone 6.) In fact some plants are treated as annuals in certain areas because conditions are not appropriate for them to survive year to year, but may be perennial in other areas. Experience will be your best teacher in your own yard, but there is a resource that can help you get started successfully. The person to help sort it all out is Cool Flower whisperer Lisa Mason Ziegler who is a cut flower farmer/florist turned author and educator.

"Cool Flowers" is Lisa's book that will give you loads of information and tips on growing your own cool flowers to get a jump on the growing/gardening season!

Last updated February 21, 2024