In the South, the weather lets us have a long growing season for our lovely blooms, but the short couple months in the Winter are a nice break to get ready for the next year. One nice way to be able to relax a bit more during that time, is to have the beds filled with cold hardy plants that you can basically set and forget until the weather starts to break again. Because I have a smaller space than most, I have to be rather selective on which plants I want to grow, but I do like the occasional trial to find something new to love! After the past few years growing in the garden, these following cold hardy flowers are my favorite picks for the 2025 Spring season.
Campanula
This is a beautifully, unique addition to bouquets, and is a fantastic filler for Mother's Day bouquets. Under the right conditions, these can grow up to 3 feet with bell buds lining the stem. This plant does better when it is provided with enough short day (less than 11 hour) conditions to allow the plant to produce more vegetative growth before it begins flowering in the long days (12+ hours). It is recommended to have about 6 weeks of short day exposure (Campana).
With that said, we planted campanula under two different conditions, simply due to necessity. The first year, the plants were in the ground well before winter approached. The plants had plenty of time to build a big, beautiful vegetative mound, and once the long days came, the plants put up massively long stems and had multiple side stems as well. The second year was...fine....but not as good. The seed starting for the plants didn't go very well, so we purchased in campanula plugs to plant in the beginning of the year. The plants grew, but the flowers didn't develop as nicely.
I would recommend harvesting the blooms on these plants when the first 1-2 flowers on the stem color-up and start to crack. When the bell is open, rain and moisture can pool in the bottom of the bell and cause the flower to rot away. The second reason to harvest early would be that cucumber beetles will find their way into the flower and start eating away at it.
Take Aways:
Start seeds late Summer to early Fall
Plant out plugs in the Fall for necessary short day exposure
Cold Hardy down to -10 °F (Lisa Mason Ziegler, 62)
Needs netting for tall, heavy stems
Long lasting cut flower and great in bouquets
Harvest when 1-3 bells have color and split open on stem
Lisianthus
This flower is a treasure in different ways. Like treasure, it can be a challenge to find where X marks the spot with growing technique. If you like a challenge, this is the plant for you! It is suggested to buy these babies in plugs because they are SUPER slow starters, which also heightens your chances of killing them before they even make it to the garden. That's up to you, but for the time being, I have been trying to perfect starting them from seed. Similar to Campanula, you want to start these plants late Summer/early Fall in order to get them planted before the Winter season.
Gardening is a trial and error exercise every year, and it just so happens, I am learning something new every year with the many errors I make. This year just so happened to be with my Lisianthus. I was excited to have multiple flats of plugs in Fall, but I planted them out too early while the temperatures were still too hot for their development. When the temperatures are hotter than your normal Fall weather (in the 80s), the plants will rosette. This means the plant becomes stunted and does not develop full, beautiful leaves, and will also cause the plant to potentially not give you flowers. I will give updates in coming months, but I believe the hard cold spells we had this winter (2025), hopefully, kicked their rosetting so that they will give me an abundance of blooms.
Lisianthus can be harvested at your own speed, essentially. The stem will have multiple buds, and when a flower opens, you can either take it early or wait until more open. When a bud starts looking ratty, you can dead-head it and the plant will continue to bloom in time. This alleviates the pressure to harvest all of them at the same time and fill the cooler.
Take Aways:
Start seeds late Summer to early Fall
Plant out plugs in late Fall with cool nights (or plants will rosette)
Cold Hardy down to 0 °F (Lisa Mason Ziegler, 63)
Needs netting for tall, heavy stems
Long lasting cut flower (7-14 days) and great in bouquets
Harvest when 1-3 flowers open
Bachelor's Button
This is by far one of the most reliable cold-hardy flowers for the cut flower grower, and the royal blue color of this gem is clearly inspiration for Garden Sapphire. Blue colors are just so limited in the landscape, and this is one of the few bold blues you will find.
The seeds are easy to start when direct sowing in the ground, which isn't always the case for your direct seeded cold-hardy plants. Making sure the soil stays moist is the key! At the end of the growing season, its easy to start losing interest in the small details of gardening, but if the soil dries out for your direct seeded plants, you will waste time and money....keep your seeds watered. When the plants start growing, you will want to thin out the babies to at least 2" apart. You can keep them closer together if you are feeling lazy and don't want to thin them out (I've been there for sure), but by thinning them, you will allow the space for a stronger stemmed plant that will produce more side stems throughout the Spring.
I have had issues with Bachelor Button (and larkspur) where some type of night dwelling rodent will eat the seedlings when they are small. This can be devastating when you finally see the plants growing, to simply have stubs left in the morning. There are lists of ways on "the webs" for how to prevent rodents in your garden, and try your best. What I have found has worked, minutely, is to have a sheet of frost cloth/landscape fabric over the plants. I am assuming that it deters them a little from the movement of it, and it also helps with preventing moisture loss. Don't hold it as gospel, though. Once the plants grow past seedling phase, they are almost never touched by the pesky night crawler again.
Bachelor Button will survive your cold winter with a hardiness down to 0°F (Lisa Mason Ziegler, 63). Once the plants are established, make sure the soil doesn't stay too wet and there is good airflow, or the roots will start rotting out and the loss will spread.
These plants can benefit from having a pinch to help with branching, but you can also wait until the first buds appear and make a deep cut on the first stem. The deeper you cut the first stem, the longer the branching stems will be as the season continues.
To get the longest vase life for the flowers, be sure to harvest when the bud has not opened but shows color. This will also help you stay on top of keeping the plant dead-headed. If you wait too long to harvest, the flowers will open and you will need to roll through the bed to clip the spent flowers.
Take Aways:
Start seeds mid-late Fall, direct seeded(can tolerate warm days)
Cold Hardy down to 0 °F (Lisa Mason Ziegler, 63)
Can benefit from netting
Prolific bloomer
Harvest when shows color, but not open
Dianthus (Sweet William)
Dianthus is one of the longest lasting cut flowers, and is remarkedly durable in the cold weather with a hardiness of -10°F (Lisa Mason Ziegler, 63). Their seeds are, also, quick and easy to germinate under the correct conditions with a reliable seed source. We have purchased ours from JohnnySeed.com, online, and have had great success every year.
Dianthus grows the best when they have cooler days and nights, which helps encourage their branching, and therefore, more flowers. To make sure you are get the most out of your Dianthus plants, seed them in late-Summer to early-Fall in order to plant them out in time to establish before the Winter frosts start. You are able to grow Dianthus outside of the cold season, but you are much more likely to be limited to one flower per plant with a shorter stem. If you are like me, and love this flower, you will choose to accept the limited single stem per plant to make sure you have this lovely lady bedazzle your bouquets longer in the season.
There is limited issues growing this plant. You will likely want to net them for the surprise wind that might topple the long stems. There are a couple insects that might cause trouble for you. Thrip and caterpillars. When you leave more than a couple of the individual flowers on the head to bloom out, you are more likely to attract thrip to the open flowers. You can reduce your thrip populations by keeping the flowers harvested on time, which is when 2-3 of the flowers open. We have also had significant leaf damage from caterpillars, which is commonly caused by armyworm, in our yard. Armyworm will hatch in clusters and leave the leaf skeleton behind. Destroy them as soon as you seem on the leaves in clusters before they spread to other areas. Thrip and caterpillars both consume parts of your plant, so to prevent large infestations, Spinosad has done us well. It will stay in the plant for about a month, and is good to apply before the plant flowers. When you apply it earlier in the plant life, it will deter the pests from attacking your plant, and will also allow the flowers to be safe once they open to protect beneficial insects from being exposed.
Take Aways:
Start seeds early-mid Fall indoors (can tolerate warm days, but may bolt if too hot)
Cold Hardy down to -10 °F (Lisa Mason Ziegler, 63)
Benefits from netting
Cold weather promotes multiple stems
Harvest when 2-3 flowers open
'Sweet™' varieties bloom earlier than 'Amazon™' varieties
Snapdragon
Snapdragons are a street-side stunner when they have their cold season to help them reach their full potential. These can be planted in the warm season, but they will not get as tall and full of blooms as when they sit through the winter. There are different groups of Snapdragon varieties that will bloom at different times of the year, but regardless, it is good to try to get them planted when the nights remain cool (50s-ish). The seeds are MINI, unless you invest in the pelleted seeds (Johnny Seed recently has come out with more). I enjoy the challenge of seeding snapdragons with one seed per cell, but you may also start them in rows, and transplant them when they get bigger. I have done both ways, and I find to have more overall success when I take the time to plant them, one per cell.
The seedlings can be planted close together, about 4", which allows you to get more blooms in your flower bed. They will absolutely need to be netted, because with one wind gust, they will fall over and the phototropism properties will cause the stem to distort. It will make your snapdragons look artistic on their own, but there is something about a perfectly upright snapdragon that screams money. I still struggle with getting the netting done properly with my snapdragons, so don't be surprised to see our bouquets with "artistic" snapdragon qualities.
There are two insect pests that I battle with snapdragon. First, is thrip. Similar to Dianthus, if you pretreat the plants with Spinosad before flowering, you will have better success preventing thrip before they even start, while also keeping your honey bees safe. The second pest I have been working to identify, but believe it is a soybean looper. They come just as the weather starts to get warmer, and they lay single, white eggs mostly on the flower buds. When they hatch, they chew a nasty little hole into the flower bud, before it even opens, and causes unsightly damage, rendering the whole stem useless. My main system to prevent this menace has been to individually remove each egg, but when you have a whole bed full of buds, it is exhausting. Since the eggs are laid by moths that roam at night, I have tried garden netting to cover the plants and provide a barrier to the night flier. It has worked, but when the flowers get tall, it gets a little trickier to cover.
Take Aways:
Start seeds early-mid Fall indoors
Cold Hardy down to 0 °F (Lisa Mason Ziegler, 63)
Must be netted, phototropic properties
Cold weather promotes tall, strong stems
Harvest when 1/3 flowers on stem open
Different variety groups do better in different weather
Thrip and Moth eggs on blooms cause damage
Ammi (Queen Anne's Lace)
Ammi, or Queen Anne's Lace, might not sound like a flower you would want to grow as a cut flower since it is more widely know as a weed, but the elegant qualities of this flower will surprise you. The dainty, white flowers of Ammi provide a wide spray that fills out a bouquet. When harvested early, the flowers will last a full week in the vase as the small blooms unravel.
This plant is one that can be direct seeded, but this past year, I decided to start the seeds in flats. Ammi is a plant that grows a tap root, and these types of flowers don't take root disturbance well. Therefore, it is usually recommended that you direct sow the seeds in the ground. In the past years, I have found my germination results after direct sowing to be less than tolerable, so this year I took my chances with root disturbance, and sowed the seeds in flats. The germination in flats was great, and after planting the seedlings out in the garden, they didn't show any signs of distress. This also allowed me to set plant spacing exactly how I wanted.
You can grow these plants close spacing (2") or further (9"). The more space given to the plant allows for a thick, sturdy stem to develop on a very tall plant. The tall plants will give you one, main flower and after cutting, a handful of side stems. The closer spaced plants will only give you one flower, but you can cut it all the way to the ground and be done with it. This would allow for a quick transition to clear out the bed for the next planting. Both spacing methods are acceptable, and to be honest, I haven't found which one I prefer yet.
Very few complications arise with this plant. There are specifically two that I can attest to. Primarily, there is a sap in the stems of this plant that isn't visible but cause phototoxic dermatitis. When the chemical in the plant touches your skin, the exposure to sun causes blisters to form. When harvesting these flowers, I recommend making sure to have all skin protected from exposure. Whenever I'm feeling rebellious, and don't properly cover up when I'm cutting this flower, I always end up with lovely Ammi scars. The other, not so dire, issue with this plant, is its attraction to Black Swallowtail butterflies (one of my favorites). I love seeing the butterflies lay their eggs on the plant, but then I have to follow after them and make sure I collect the eggs. I take care of the babies when they hatch, but I can't let them mature on the plant, or I will end up selling bouquets filled with baby butterflies.
Take Aways:
Start seeds early-mid Fall indoors or direct seed
Cold Hardy down to 10 °F (Lisa Mason Ziegler, 62)
Must be netted
Harvest when 1-3 small flower open
Causes phototoxic dermatitis
Attracts butterflies
Works Cited
Campana, Campanula. GrowerFacts.https://www.ballseed.com/utility/seedcolumnpdf.aspx?txtphid=013006226014207
Lisa Mason Ziegler. The Cut Flower Handbook. 2023. Quarto Publishing Group USA Inc., 27 Feb. 2024, pp. 62–63.
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