11 Frost-Hardy Flowers You Can Grow from Seed
Many flowering plants will die back at the first signs of frost, but there are a few that are able to tough out the cold. Gardening expert Madison Moulton lists 11 frost-hardy flowers you can grow from seed this season.
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Looming frost spells the end of the flowering season for many plants, annual or perennial. Several popular garden flowers don’t appreciate the cold and die back when temperatures drop (even if they do come back the next year).
But that’s not the case for all flowers. Many can handle temperature drops and light frosts with ease, continuing to thrive and even flower in these conditions. The key is choosing the right species and varieties and knowing the plant’s limits to provide protection at the perfect times.
This list of frost-hardy flowers is ideal for filling your fall, winter, or early spring garden with beautiful color. A few of them flower in summer, too. Grab your seedling trays, choose your favorite varieties, and get planting!
Alyssum
Sweet alyssum is an adorable and versatile annual. They look just as great alone in containers as they do mixed amongst vegetables in your beds, attracting pollinators and flowering profusely in milder conditions.
Alyssum is a frost-hardy flower, but only once the plants are established. They tolerate light frosts early in fall but will stop flowering after consistent freezes. Keep your plants protected until they are established to stop frost from damaging tender new growth. Generally, sweet alyssum is sown four to six weeks before last frost indoors and one to two weeks before last frost outdoors. But in mild climates, fall sowing is recommended for winter blooms.
Traditional white alyssum is the go-to for many gardeners, matching well with any garden color palette. Varieties like ‘Tiny Tim’ are a great choice in this case. But if you want a brighter pop of color, try the purple ‘Oriental Nights’ or pink ‘Rosie O’Day’.
Quinoa
Many of us know quinoa best from the delicious grain on our dinner plates. But did you know that the tall, spiked flower stalks are gorgeous ornamentals, too? Plus, if you’re starting a cut flower garden, they look great in arrangements and hold their shape and color well after drying.
Quinoa can survive light frosts and freezes. It prefers the cool temperatures of spring and fall (32ºF to 50ºF) but doesn’t mind the occasional temperature drop into freezing once mature. These plants are beautiful and tough. However, make sure to protect tender young seedlings with frost cloth or other winter protection, or wait to sow outdoors until after your last frost date.
You have some options when growing these frost-hardy bloomers from seed. My favorite for a burst of color is ‘Brightest Brilliant Rainbow’ quinoa, which brings a spectrum of colors in red, yellow, orange, white, and green. The plants are also drought and deer-resistant.
Calendula
Calendulas are also known as pot marigolds, appreciated for their warm hues and versatility. These beginner-friendly blooms tolerate a wide range of conditions, including drought and frost, while still pushing out their sunny flowers. The edible blooms are used in teas and dyes, and in the garden, they attract buzzing pollinators to your backyard.
Calendula continues to be tough in the face of frost, handling moderate temperature dips with ease. They will keep flowering after a light frost, depending on what climate you live in. In cold climates, start seeds indoors four to six weeks before your last frost date. In mild climates, sow in early spring for summer flowers or late summer for winter flowers.
The best part about growing calendula in the colder months is their ability to brighten up your garden with warm hues. ‘Pacific Beauty’ and ‘Oopsy Daisy’ deliver in this regard. Or you can opt for the softer and more delicate pink ‘Zeolights’ calendula.
California Bluebells
Phacelia campanularia is a native flower from – you guessed it – California. You may also see them called desert bluebells, or simply desertbells. The blooms may be tiny (one inch in diameter), but their vivid blue hue makes them hard to miss in the garden.
Direct sow your seeds for the best results. In colder climates, sow your first seeds around four weeks before last frost. In milder climates, sow again in late summer and early fall for cool-season blooms.
These frost-hardy flowers don’t mind the cold of early spring, bringing a pop of blue to your beds or containers even in colder regions. They withstand temperature dips better when well-established, so keep younger plants protected until then.
Coneflower
Echinacea is a must-have in any garden, but particularly in pollinator gardens, where their drooping blooms attract masses of butterflies. Coneflowers are also tough, a great frost-hardy flower for beginner gardeners looking for a low-maintenance perennial.
Coneflowers live through light frosts, even as young seedlings. Direct sow outdoors from four weeks before last frost to as late as two months before first fall frost. Indoors, start seeds 10 to 12 weeks before your last frost date. They will die back if temperatures drop too low, but don’t panic—they will pop up again the following spring. They also handle poor soils, drought, and heat without complaints.
You probably recognize the purple coneflower, but there are many more interesting varieties to choose from. ‘White Swan’ is ideal for gardens with a neutral color palette, while ‘Paradiso Dwarf Blend’ provides an explosion of color that looks particularly impressive in containers.
Sweet Annie
The light and feathery chartreuse plumes of sweet Annie are already a favorite of most dried-flower and craft lovers. These sweet herbs dry beautifully and give an airy, ethereal quality to arrangements.
Sweet Annie is a cold-hardy annual herb with a camphor scent used in bundles to deter moths indoors. Outdoors, it’s a favorite of pollinators like butterflies and bees.
While the plant can handle some light frosts, you’ll still need to protect tender seedlings from early spring freezes. Alternatively, you can direct sow them one to two weeks after your last frost date.
Dianthus
The Dianthus genus is full of intricate and beautiful blooms that look right at home in any cottage garden. There are several wonderful species to choose from, from delicate sweet William to cottage pinks and carnations.
Dianthus blooms from spring to summer, depending on the species. Although the flowering period ends in summer, the plants will generally handle light frost well without dying back. Only serious freezes will kill off the narrow foliage. Start seeds indoors around eight to ten weeks before your last frost date and continue sowing until early summer for bloom the following season.
Sweet William is a great frost-hardy flower for classic cottage gardens, particularly the charming ‘Double Blend’ mix. For a more soft and airy look, ‘Rainbow Loveliness’ is a great choice.
Iceland Poppies
Every fall, Iceland poppies are at the top of my planting list. These stunning blooms are large and eye-catching in the garden, and they look even better in a vase. A staple in my cut flower garden, the tall stems make putting arrangements together a breeze.
The name of these flowers is a clue to their frost-hardy nature. While they prefer moderate temperatures over extreme hot or cold, these poppies don’t mind a few icy days. They are best sown directly into the ground four to six weeks before last frost, or in late summer or early fall in mild climates. The flowers will pop up the following spring.
Choose your varieties wisely if you need them to withstand frosty conditions. ‘Nudicaule Blend’ provides a variety of warm hues to enjoy, from classic red to stark white and everything in between.
Pansies and Violas
Pansies and violas are a staple of winter gardens, performing their best in cooler weather. Their bright hues and intricate patterns uplift gloomy gardens, even when frost looms. The blooms are also edible, great for adding some color to your winter salads or desserts.
These annuals are the first I reach for in fall to fill containers or hanging baskets. The amount of flowers one plant produces is almost unreal, giving you plenty to enjoy in the garden and the kitchen. Plus, you’re never short on choice, particularly when growing from seed. Start seeds in midsummer in cold climates for fall flowers, or direct sow in late summer in mild climates to miss the heat.
For an explosion of color, ‘Swiss Giants’ pansies are a perfect option, named for the larger-than-life flowers. Or you can go with something more moody and dramatic, like ‘Black to Black’ violas. You’re bound to find at least one look you fall in love with shopping for seeds.
Snapdragons
Snapdragons perform exceptionally well in mild climates, surviving light frosts and producing waves of vibrant color throughout the season. They are not only frost-tolerant but also a favorite of pollinators, great for filling gaps as spring and summer blooms fade. Start the season early by sowing eight to ten weeks before last frost indoors, or direct sow outdoors as soon as the soil can be worked. In mild climates, sow in late summer for winter and spring flowers.
To maximize their frost tolerance, give them a sunny spot to soak up the last warmth of the year. I love planting them in containers where the flowers can really shine, or mixing taller varieties with other annuals in beds for some extra height.
Like pansies and violas, you won’t struggle to find a color you love when growing snapdragons. ‘Orange Wonder’ delivers warm hues that brighten any garden, while ‘Night and Day’ contrasts deep burgundy with creamy white for an elegant, moody look. For those with smaller spaces, ‘Magic Carpet’ brings a compact burst of color, ideal for edging or smaller pots.
Sweet Pea
The final entry on this list is the toughest frost-tolerant flower of them all. Few ornamental plants work for cool-season plantings like sweet peas. Their ruffled petals and intoxicating fragrances aren’t the only features to enjoy.
Sweet peas thrive in cooler weather and are one of the first flowers to bloom in early spring, a must-have for extending your flowering season. While sweet peas can handle frost, it’s best to plant them in a protected spot to shield younger plants from harsher cold winds if that is a common occurrence in your region. Direct sow six weeks before last frost, and in late fall in mild climates for spring blooms.
For large blooms, ‘Mammoth Blend’ provides classic hues that uplift any empty spaces. If you’re looking for something daintier, ‘Little Sweetheart’ is a compact option with a sweet charm perfect for containers. For a touch of drama, ‘Beaujolais’ has wine-colored blooms perfect for creating striking bouquets.
