Growing Cool Flowers

When I first started growing flowers, my focus was completely on mid-Summer blooms - dahlias, zinnias, sunflowers. That was the extent of what I knew, and to be honest, I spent that first year wondering why I had TONS of flowers end of July through the first frost - but nothing before. It was pretty disheartening, and while I am head over heels for what I now think of as hot flowers, I was wondering what exactly I was missing here.

I fell into a “Zone 4” trap. I thought for sure I had extremely limited options for naturally grown Spring flowers due to the climate I was in, and that I would have to spend lots of time (and money) to have flowers earlier.

This all changed when I started researching, and intentionally spending my time learning about different flowers and the conditions they thrived in. My search led me to the book "Cool Flowers: How to Grow and Enjoy Long-Blooming Hardy Annual Flowers Using Cool Weather Techniques” by Lisa Ziegler. This book changed the entire trajectory of what, when and how I grow my flowers.

By the time I joined the workshop from Floret Flowers, I had a baseline knowledge of what cool flowers would work in my growing zone (if you’re not sure what zone you are in, you can find it here). Turns out, there are a lot of fun options!

In this post, I am going to focus on the cold hardy annuals I plant, and when I start the seeds for my zone. The majority of seed packets you can buy give great info on germination temperature and when to start the seeds, but since they are printed to cover basically all US hardiness zones, there’s a lot of wiggle room. In a later post, I’ll talk more about perennials, and the perennials that can be treated as annuals for cut flower purposes (i.e. tulips, daffodils, etc).

An annual plant is one that you would plant each year, as new. I start all of my flowers from seeds, and I try to finalize my garden plan in October for the following season. Key word is try - as some seeds germinate better than others, or I find a new variety I just HAVE to have, things get moved around. Having a solid plan keeps my budget somewhat in check, though, and allows me to focus on a set path of when to start seeds and how many to start at a time.

This year I am intentionally succession planting, to make sure that I have blooms over a prolonged period of time. This also saves space in my grow areas and I find that it’s less frenzied as I move into starting hot flowers.

I am pushing the envelope on a few types this year to see how they handle temps in the mid teens. I plan to have my cool flowers in the ground at the end of March as long as the soil is workable, so we will most likely have periods where we go below the teens. In those instances, I use frost cloth and landscape staples to cover the plants.

In mid January (January 18 to be exact), I started seeds for Bachelor’s Buttons, Dianthus, Snapdragons and Sweet Peas. These were all started in soil blocks, with Pro-Mix picked up from Menards. They all germinated, and are getting nice and big, which is great! They started off on racks with grow lights in my home office, where the temperature ranges between 68-70 degrees. From there, I started the seeds for Rudbeckia, Pincushion Flower (Scabiosa), Orlaya, Love in a Mist, more plantings of Lisianthus, Linaria, Hollyhock, Forget Me Not, Clary Sage, Cerinthe, Buplerum, Canterbury Bells, Queen Anne’s Lace (Ammi), Apple of Peru and Agrostemma. All of these will have multiple succession sowing.

Once the seedlings are about 4 weeks old, they’re moved out to our heated garage that stays at 50 degrees. This lower temp has seedlings developing roots, and I’ve found they get less “leggy”, keeping them at a better overall health. In two weeks, the first round will be moved out to my unheated greenhouse to get hardened off for planting time.

Hardening off can’t be skipped - if you don’t allow your seedlings to get used to the outdoor day and night temperatures, they’ll die and you won’t have any flowers! So don’t get ahead of yourself and don’t rush the process.

I have also began the process of pre-sprouting my ranunculus and anemone corms - these are somewhat high maintenance, as they need to be soaked for a good 4-6 hours prior to being placed in a tray with soil. I place the corms in mesh bags and also use an aerator pump (this one) to keep the water moving and provide air to the corms as they soak. After they’ve doubled in size, I place them in a 10x20” tray on top of an inch of soil, and then cover with soil and a humidity dome. They can’t be dried out, but you also don’t want them to grow mold. The trays are then put into a dark, cool space (bottom shelf of a wire rack in my garage) until green sprouts appear, and then I put them under lights. The ranunculus will be planted out at the beginning of April, with the anemones going in closer to the end of April. Ranunculus can handle temps down to the low 20’s, and anemones like it a bit warmer - they can handle temps in the 30’s.

What kind of cool flowers are you interested in? Do you grow any?

A note: I’m not compensated for any links or products I share - everything I share are items/content I paid for myself, and am sharing as they worked for me!