One of the challenging things about being a flower farm in a cold climate with a short growing season is that the growing season is so short, and you typically don’t really get into flowers until the last week of July! That being said…
If you know how to grow cool flowers (and you’re brave enough to set things out in cold temperatures when others wouldn’t dare), you can have a beautiful harvest by the last week of June! Try any of the flowers in the hardy annuals list below for an earlier harvest in your cold climate.
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Notes about growing cool flowers in a cold climate
- When planning to grow cool-season flowers, you should definitely buy both shade cloth and frost cloth. Have both on hand and use when the weather requires it.
- It is important to remember that bugs still exist before May 21st!! Know that there could be a flea beetle infestation when you’re least expecting it. In fact, bug and pest infestations can be worse because there is nothing else for the bugs to eat… and you’ve just provided them with this beautiful buffet!
- If you live in a warmer zone (Zone 6 and up), follow the advice in Lisa Mason Ziegler’s fantastic book Cool Flowers: How to Grow and Enjoy Long-Blooming Hardy Annual Flowers Using Cool Weather Techniques. If you’re in Zone 5 and down, implementing cool flowers looks quite different. If enough people comment on this post or social media saying they really want to know more about growing hardy annuals in a cold climate, I will write a guide to cool flowers. The book has been swirling in my head for years!
- You can treat most perennial seedlings as cold hardy flowers. If you’re running out of space and need to get something into the ground, but it still might freeze, it’s best to prioritize planting your perennial seedlings over annuals, especially if you’re not sure if they are cool or regular flowers. If the temperature freezes and some of your perennials–say your tulips or anything established in your yard–are already up, you don’t need to worry about covering them! They will be fine!
15 best Cool season annual flowers
1. Anemones
These are some of the coldest-hardy flowers of all the flowers on this list. Anemones are maybe a bit tricky to start because you do have to pre-sprout them, but other than that, they are quite easy to grow and are a beautiful addition to your spring garden. Just make sure you use shade cloth if the temperature gets above 24°C/75°F.
Related: How to Soak and Pre-Sprout Anemones (and Ranunculus!)
2. Bells of Ireland
Bells of Ireland are hard to germinate. I love their pretty smell and unique shape. Once you get some plants established, you can leave a few aside and stomp those seeds into the ground, and you’ll have a much easier time of things! They will still self-seed on their own but will do a lot better if you help them along!
Related: 4 Foolproof Ways to Germinate Bells of Ireland
3. Cress
If you have chickens, make sure you cover your cress as it goes to seed! They love it a little too much. It also germinates within two days, so if you’re starting it indoors, just be aware of that and make sure you’re on top of your lights and things. I was not on top of my lights last year, so between that and my chickens, I was sadly left with no cress!
4. Feverfew
Feverfew is one of my favourite cold-hardy flowers. If you leave the plants in the ground, about 50% will return next year. The magic varieties are more cold-hardy than the tetra varieties.
5. Godetia
I grow this crop specifically to be an accompaniment to my peonies (and because I like the pods at the end of the season). Godetia do tend to be kind of spindly, and the stems might not grow straight, but again, it’s still worth it for the pop of colour!
6. Larkspur
I have not successfully grown larkspur yet. I have grown about two good stems. Make sure you cold-stratify it outdoors in a seed tray for about a month and water it with snow! This should help your germination rates (and hopefully give you more success than I’ve had)!
7. Nigella
Nigella is easy to grow and beautiful for both the pods (pictured below) and the flower. I always have some on hand and seed it throughout the whole summer, so I have little hints of blue available should I need them!
8. Poppies
Poppies do not have a good vase life, but I still like growing them because their papery thin petals are so beautiful. I prefer varieties that have larger seed heads to use later in the year. Poppies do not like to be seed-started, so directly sow them as soon as the ground is workable!
Related: How to Grow Poppies in Zone 3
9. Queen Anne’s Lace
I grow Queen Anne’s Lace (also known as Dara) because I often need something that is white. It’s so cold-hardy and so reliable that you don’t need a huge patch of it, and it’s also nice to have as an emergency flower. The flowers do tend to be droopy if you pick them too early. And while it’s not the prettiest flower in the garden, it helps your hero flowers shine!
10. Ranunculus
Ranunculus are the divas of the cool-hardy flowers. They’re a little complicated to start because you have to pre-sprout them and pests absolutely love them! I’ve had years where there are three different pests munching on them all at once, but when you do it right, they are so good. Make sure you have shade cloth on hand if it gets to 24°C/75°F or warmer!
Related: How to Grow Ranunculus in Zone 3 (So They Don’t Die!), Are Dollar Store Ranunculus Corms Worth It?, How to Soak and Pre-Sprout Anemones (and Ranunculus!)
11. Saponaria
Saponaria is also one of my favourites. You get really long, strong stems from them and they’re a good alternative to baby’s breath!
12. Snapdragons
Snapdragons are the backbone of the cut flower garden. I always start one early succession just to have them, and, in the fall, they are good up to 10°C/50°F. My favourite snapdragons are the Potomac Mix and the Madame Butterfly Mix.
13. Statice
It’s no secret that I love statice. They are great for dried and fresh arrangements and come in so many beautiful colours!
14. Stock
Stock is a one-and-done flower. It’s so fragrant and beautiful that I think it still deserves a place in your garden. Stock is very easy to start from seed and my favourite variety is the Rainbow Quartet.
15. Sweet Peas
Sweet peas are hard for me personally to grow. Last year, I found the key was to start indoors in March, and I had much more success than when I direct sowed. If you do direct sow your sweet peas, get them into the ground as soon as the snow melts!
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READY TO push the boundaries of your cold climate garden?
Do you live in a cold climate with a short growing season and feel frustrated with how few weeks you have with your cut flowers? No more! I’ll show you how to add a potential 45-60 days to your flower season by utilizing cold-hardy annuals in both spring and fall. What could two extra months of flowers do for you?
Learn more and grab your digital copy of Frost Proof Flower Garden today! Prefer a physical book? Check out the print edition here.
Kenny