May is a dreamy moment in the garden, when many popular blooms peak at once, usually overlapping with Mother’s Day and spring weddings. Springtime blooms such as snapdragons and sweet peas hold a poignant, grandmotherly nostalgia for many flower lovers, and we get dozens of questions about growing these classically romantic beauties at home. Southern gardeners have a tiny window of opportunity to enjoy a true English cottage garden vibe in the spring, and the timing is tricky. We’re here to work backwards from the current abundance and help you plan for next spring’s cutting garden. Please note that all advice here is based on gardening in Zone 7, and is entirely based on our experience growing in Raleigh, North Carolina. There may be wiggle room around what we suggest here, and this may not be relevant if you are in even a slightly warmer or cooler climate. We encourage you to experiment with growing southern spring flowers!
The trick for Southern growers to achieve their spring cottage garden vision lies in the timing. Most of the popular spring bloomers are “hardy annuals:” cool-weather-loving plants that want to get established during the chilly months before putting on their frilly show from about April to June, setting seed, and dying back. I like to think of gardening as surfing a wave: you need to catch the natural motion early enough to sustain the momentum and see the desired results. With hardy annuals, this means getting a head start in autumn or even late summer so that your seedlings can establish a healthy root system over the winter that will enable them to bloom successfully in spring. Since temperatures often get warm very quickly here in Zone 7, spring-planted hardy annuals are often prompted to bloom long before they are well established, which results in short, stubby blooms rather than long, graceful stems and fully formed flowers.
Garden centers, especially big box stores, will often market seeds and plants to shoppers during the season in which they bloom, which gives shoppers no real opportunity to get a plant established in the garden before its optimum bloom window closes. It’s very confusing and frustrating for gardeners who buy plants because of their eye-catching blooms in the store, only to see them fail in the garden. Instead, in order to grow a successful flower garden, you need to think and plan two to three seasons in advance to ensure a proper growth cycle. This sounds complicated, but once you learn to catch the seasonal waves, you will ride them effortlessly. Below we’ll outline our timing for five favorite spring bloomers that we’re confident you can enjoy in your own southern spring flower garden.
Most hardy annuals are highly tolerant of frost and can happily overwinter in the garden without any protection. In the case of very cold, hard freezes or ice storms, a row cover such as Agribon helps to prevent cold damage. It can feel counterintuitive to plant right as temperatures are dropping, but you can rest easy knowing that your hardy annuals will be happy with the cold. This is a helpful practice for gardeners in learning to let go and trust nature’s cycles.
The “Mother of Pearl” and “Angels Choir” varieties of Shirley Poppy are among our most favorite flowers. The almost iridescent, crepe paper blooms dance in the breeze and each bloom is totally unique, with incredible variations of color from red to mauve to blush to an almost grey lavender. We direct seed Shirley Poppies from October through early January, simply sprinkling them onto the prepared bed in rows and pressing them into the soil. Water them in after seeding, and wait patiently for them to emerge. The seedlings are very cold hardy but may benefit from a row cover during very cold (below 20) temperatures. We cover the bed with row cover right after seeding to keep birds from snacking on them, and this is a wise practice for any surface-sown seeds that are vulnerable to disturbance. Once seedlings have a few sets of leaves, we thin them to about 4-6” apart. Once poppies start blooming, harvest them just as they start to open, and cauterize the end of the stem with a lighter for longer vase life. Hot temperatures will cause poppies to die back, but the plants will keep producing as long as you keep harvesting and temperatures stay below about 80 degrees.
We start snapdragons indoors in August and transplant them into the garden in October. Most seed packets will tell you to start snaps indoors 8 weeks before the last frost. If you are doing fall planting, you can use that same timeframe as guidance: just start your seeds indoors 8 weeks before you plan to transplant. Snaps have tiny seeds that need slightly cooler temps and exposure to light in order to germinate. So while we typically start seeds on a heat mat before moving them under lights, trays of snapdragon seeds are surface-sown and then put directly under the grow light without a heat mat. This method has worked reliably well for us. Once transplanted, snapdragons are highly cold tolerant and shouldn’t ever need to be covered over winter (we’d probably cover small plants if temps dropped under 20 degrees). Once seedlings reach 6” tall, pinch off the tip down to the next leaf node so that your plants will branch and become sturdy, with many flowering stems. These beauties will keep blooming as long as you keep cutting, from about mid April into June. We like to plant a mix of Chantilly, Madame Butterfly, and Potomac series Snaps, as they mature in a slightly staggered pattern and will give you a larger total bloom time together.
We plant sweet peas following a similar timeline to snapdragons, seeding them indoors without heat (but with darkness) around mid August to be transplanted in October or November. We have also planted sweet peas out as late as early January, but wouldn’t recommend planting any later than this. Sweet peas can also be direct-seeded between October and early January. Starting indoors earlier simply gives us more of a head start for the plants to establish robust root systems, which is critical for getting a successful crop in our climate. The earlier you start, the more blooms you are likely to enjoy. Sweet peas are quick growers, so it helps to give their roots plenty of space right away, either in 4” pots or a root trainer tray. Like snaps, sweet peas should be pinched when they reach about 6” to encourage branching. Transplant your sweet peas into a bed where you can provide a trellis, or up against a fence. They are hungry little plants who thrive in rich soil, so we create a trench filled with compost and transplant into that, fertilizing with a liquid seaweed/fish emulsion fertilizer a couple times over their life cycle. There is lot of variability among sweet peas in terms of their performance in warmer temperatures; we’ve found the Bristol variety to be very productive, followed by Nimbus, Mollie Rillstone, and Windsor. We encourage you to start a couple plants each of several different varieties your first time, and observe which are happiest.
While lesser known than its companions on this list, Agrostemma deserves a place of honor alongside the classics of spring. While visually delicate, the long and slender stems of ethereal white blooms are quite sturdy. They make an incredibly graceful cut flower, either en masse or incorporated into bouquets as an airy, gestural element. Agrostemma needs no babysitting over the winter and can simply be direct seeded in rows (at the depth noted on the seed packet, covered with soil and watered in) in October or November. Seeds should be sown fairly thickly down the row and then thinned to about 4-6” apart once they have a couple seeds of leaves. Once in bloom, keep harvesting regularly to ensure a longer bloom period. This spring, we harvested a whopping 250 stems in one week from a 6’x2.5’ bed! This seemingly soft flower is really a force to be reckoned with, and one we hope you’ll try in your garden.
The quintessential fairy garden flower, Foxglove is probably the trickiest on this list, simply because you need an even longer head start to ensure blooms in its first spring. Foxglove is often treated like a hardy annual, but it is actually in most cases a biennial, which means it blooms in its second year. You can kind of manipulate it into blooming in the first spring by starting the seeds during summer and planting it out in late summer or early fall. We sow the seeds in an open tray without a heat mat indoors around July, then bump up the seedlings into their own pots and let them grow a few sets of true leaves on the porch before moving out to the garden in September or October. They don’t want to be transplanted in the heat of summer because they prefer the cool weather, but they are tougher than their hardy annual counterparts. With this nice long head start, most foxglove will bloom the following spring into early summer. Make sure to read the seed packet for whichever variety you are starting; if starting a biennial variety you will need to remove it and replant it next season, but if you are starting a perennial variety (there are a few), you can trust that it will return each spring and won’t need to be started every summer. We find that the ‘Camelot’ series are reliable bloomers in their first spring. There are few sights as lovely to us as Foxglove in the garden, with its dramatic height and demure freckles. If you choose to use it as a cut flower, please be careful to display them out of reach of pets and nibbling children — they are highly poisonous and can be fatal if ingested. A couple stems in a bud vase on a mantel or high bookshelf is delightful!
The following hardy annuals are also easy to start in autumn for your spring garden. If the seed packet recommends transplanting, follow a similar timeframe to the snaps or sweet peas. If the packet says direct seeding is preferred, treat them like poppies or agrostemma.
- Larkspur (direct seed in fall through early January)
- Bachelors Buttons (direct seed in fall)
- California Poppy (direct seed fall through late winter)
- Calendula (direct seed fall through later winter/early spring)
- Sweet William (start indoors and transplant from fall through late winter)
- Silene (start indoors and transplant in late winter)
- Honeywort (start indoors and transplant in late winter)
- Statice (start indoors and transplant from fall to late winter)
- Stock (start indoors in summer or fall and transplant out before january, it has a strong preference for cold)
- Rudbeckia (actually a perennial but can be treated as a hardy annual)
- Bee Balm (actually a perennial but can be treated as a hardy annual)
For further study, we highly recommend Lisa Mason Zeigler’s books on successful southern cutting gardens, focusing on hardy annuals, which she calls “cool flowers.” Her books include:
If you need guidance getting started with seed starting, the following blogs may be helpful:
If you are unsure if a particular plant is a hardy annual, search for the “hardiness zone” of that plant. Hardiness zones designate in which parts of the country a particular plant will survive the winter, based on average temperatures. The lower the number, the colder the zone. So for gardeners in Zone 7, you want to find plants that are hardy to Zone 7 or lower. If a plant is designated as hardy to Zone 8 (south of us), it will most likely die back during our winter if exposed to the elements.
Good luck and happy gardening! We wish you abundant success growing southern spring flowers.