I’m staring at my seed box right now and it’s a mess. (I mean, it’s always a mess. But this time of year it’s a PARTICULAR mess.) There are envelopes with my handwriting that I can barely read — “zinnia? maybe?” and “definitely not marigold, bought at the swap” — and a few packets I ordered back in January that I completely forgot about until my husband pointed them out yesterday.
He said, “Amber, you have seventeen packets of cosmos and zero plan.” He’s not wrong.
But here’s the thing. May is NOT too late to start flower seeds. In fact, for a lot of what I grow, May is about perfect.
I used to think if I hadn’t sown everything by April 15th, I might as well give up and buy plugs at the nursery. (Have you seen plug prices this year? My wallet is still recovering from last season.)
But here is the thing… May is NOT too late to start flower seeds! In fact – and this surprises many of us gardeners – for a lot of summer bloomers I grow, it is just about perfect timing: warm soil, longer days, and seeds that wake up fast and strong!
So if you’re currently side-eyeing your empty beds and thinking “I should have started something in February,” oh, you sweet summer child. You didn’t miss anything. You skipped the drama. The fungus. The leggy seedlings taking over your life. The grow light that buzzes.
So anyway —here are the 12 flowers I always sow in May, direct into warm soil, with zero regrets and maximum payoff. Some are cutting-garden staples. Some are pollinator magnets. One of them smells like grape bubblegum. (I’ll let you guess which.)
Sunflower (Helianthus annuus)
Obviously I had to start with these giant, hairy-stemmed goofballs. Is there anything more “summer” than a sunflower face staring at you over the fence?
Its rough, massive and slightly scratchy leaves—on the upper page especially—will keep their bright green tonality all through the dog days! The whopping, brilliant yellow and creamy petals form magnificent, radiant halos that keep this intense glow all summer long. It is an iconic flowering plant, with gorgeous blooms that come in 70 to 100 days from sowing, to announce the high summer to your garden.
The massive seedheads, that look like dark fuzzy cushions, are packed with vitamins and have a delicious earthy flavor, and they are very decorative too! But there is a trick to them: birds and squirrels love them! So we direct sow the seeds 1 inch deep—spacing small ones 6 inches apart, and giant ones 18 to 24 inches—and cover the row with bird netting until the seedlings emerge in a week.
To keep them blooming until October, alwys plant sunflower seeds on succession every two weeks through May and into early June! Take your pick of cultivars: ‘Mammoth’ for 10-foot giants, ‘ProCut Orange’ for pollen-free branching cut-flowers that won’t shed on your tablecloth, ‘Teddy Bear’ for fluffy pom-poms, or ‘Italian White’ for soft cream. Indeed, the finches and little birds to your garden will add a spark of joy and happiness as they pluck the seeds. They are invaluable for back-of-borders or for jaw dropping flower arrangements you can be swapping with neighbors!
Bachelor’s Buttons (Centaurea cyanus)
If you are looking for an unusual and very special true blue flower… Its finely textured, soft and lance-like leaves will keep their silvery blue tonality all through the early summer! The many small, exquisite, papery petals form fringed, delicate blossoms that keep this radiant glow for weeks.
It is an old-fashioned flowering plant, with brilliant cobalt blue, pink, white, and almost-black blooms that come in just 65 to 75 days, to announce the cottage garden season to you, your family and pollinators. The stiff, wiry stems, that dance in the wind, hold the blossoms perfectly, and they are very decorative too!
What’s more, the bees and little winged visitors to your garden will add a spark of joy and happiness as they visit the drifts of blue. We direct sow them 1/4 inch deep and 8 inches apart.
They self-seed reliably, so if you plant them once, you will likely have them forever, saving you money! However, in hot southern zones, they might fizzle after 6 to 8 weeks; so we succession-sow every 3 weeks! They are absolutely perfect for planting in drifts with poppies and ammi of you want it. Cultivar picks include classic ‘Blue Boy’, moody ‘Black Ball’, ‘Polka Dot Mix’, or sweet ‘Pinkie Rose’.
Zinnia (Zinnia elegans)
Or as I like to call them, the absolute “best friend” of every beginner gardener. Honestly, if you can’t grow a zinnia, well, we might need to have a little talk over the fence, friend! They are sooooo easy it almost feels like cheating. I love the way the petals feel—almost like stiff little pieces of colorful paper—and they come in every shade imaginable except blue.
I’m partial to ‘Queeny Lime Orange’ when I want to feel sophisticated, but the ‘Oklahoma’ mix is just pure nostalgia for me. I usually just direct sow the seeds directly into the garden about 1/4 inch (0.6 cm) deep once the ground is nice and toasty—around 70-75F (21-24C)—and try to give them at least 6-9 inches (15-23 cm) of elbow room so they don’t get claustrophobic.
What’s more, the monarchs, swallowtails and little winged visitors to your garden will add a spark of joy and happiness as they create a tiny, colorful mosh pit right over the blooms!
But here’s the thing—I found out the hard way that zinnias are total drama queens about having “wet hair.” I once sprayed them from above with a hose and they caught powdery mildew so fast it made my head spin! REPEAT: WATER AT THE BASE.
And let’s be honest, once they have about 4 leaves, you have to do the “unthinkable” and pinch out that center stem. It feels sooooo wrong, like you’re hurting your baby plant, but it triples the flowers and suddenly you’ve got a bushy monster instead of a lonely stick. Plus, have you seen the price of sophisticated bouquets lately? You’re basically printing money in your backyard.
Yarrow (Achillea millefolium)
Its lush, dense, and finely textured fern-like leaves will keep their deep green and slightly silvery tonality all through the year! The many tiny, dense, papery flowers form large, flat clusters that keep this vibrant glow all summer round. It is a phenomenal, medicinal flowering plant, with brilliant yellow, fiery red, and pink blooms that come in 100+ days, to announce the wild meadows to you, your family and pollinators.
The stiff, upright stalks, that look like sturdy little umbrellas, are perfect for cutting, and they are very decorative too! Even so, the little winged visitors to your garden will add a spark of joy and happiness. We direct sow on the soil surface because the seeds are tiny and need light, keeping it moist for 2 weeks until germination.
Like coneflower, it hates rich soil; treat it mean, lean, and dry for sturdy plants! I can hear you… “Is it really medicinal?” you are thinking. Yes! I crushed up yarrow leaves on a bad cut in 2018 and the bleeding stopped within a minute! Its very unusual personality males it invaluable for wild borders, and you can take your pick from ‘Moonshine’, ‘Paprika’, or ‘Cerise Queen’.
Tall Verbena (Verbena bonariensis)
This is the coolest flower for adding whopping height and movement to a garden! It shoots up with incredibly skinny, rough green stems that seem almost invisible from a distance. The sparsely leaved stalks are stiff and wiry, creating a towering, see-through structure. Floating right on top of those 4 to 5 foot stems are small clusters of brilliant purple and lavender flowers.
They hover like little purple clouds in late summer, announcing the changing season to you, your family and pollinators. The tiny, tight seed clusters that form after the blooms fade are incredibly textured, and they are very decorative too!
And – let’s be honest – the monarchs, swallowtails, and little winged visitors to our garden will go bananas for it, adding a spark of joy and happiness! It reseeds aggressively in a good way, so once planted, you have it forever! To get these lavender clouds, we direct sow on the soil surface because they need light, barely covering them, and thin the seedlings to about 18 inches apart. They take 90+ days to bloom from seed, getting going in late summer and blooming heavily into fall!
Nasturtium (Tropaeolum majus)
Nasturtium may sounds like a fancy spell but basically translates to “most adorable plant you can possibly ignore.” If you have a patch of soil that is absolute trash—I’m talking gravel, clay, or that weird spot by the driveway where nothing grows—slap some nasturtiums there and call it a day.
I’m genuinely impressed by how they flourish on neglect. I once tried to be a “good” plant mom and gave them rich compost and fertilizer; big mistake. I got a forest of waxy green leaves but zero flowers! They’re shy like that. Just direct sow the seeds 1 inch (2.5 cm) deep and 10 inches (25 cm) apart. They germinate best when the soil is warm, around 70-75F (21-24C), and they’ll be ready to show off in about 50-60 days.
I love the way ‘Black Velvet’ looks with those jaw-dropping near-black blooms tucked into the dark foliage. And yes, every part of Nasturtium is edible! The leaves taste like peppery arugula and the flowers add such a funky, beautiful note to a salad. Plus, they’re amazing at luring aphids away from my tomatoes and squash—they’re like a little sacrifice for the greater good of the veggie patch.
Tickseed (Coreopsis)
And we have one of the most underrated, tough flowers out there… Its delicate, finely textured and bright green foliage will keep their fresh color all through the dog days! The many small, exquisite, waxy petals form a massive, spreading mound of daisies that keep this cheerful glow from June until first frost if you deadhead them.
It is an incredibly abundant flowering plant, with brilliant yellow, red, and pink blooms that come in just 60 to 70 days for annual types, to announce the endless summer to you, your family and pollinators. The slender stems, that look like delicate green threads, hold the flowers high, and they are very decorative too!
And – let’s be honest – the bees, butterflies, and little winged visitors to your garden will add a spark of joy and happiness as they flock to the vibrant colors. We direct sow them 1/8 inch deep—light helps germination—and 9 to 12 inches apart. You can choose the fast annual C. tinctoria or the long-lived native perennial C. lanceolata, saving you money over time! Cultivars like ‘Plains Coreopsis’, ‘Early Sunrise’, and ‘Mardi Gras’ are invaluable as ground cover or in borders.
Coneflower (Echinacea purpurea)
This whopping perennial is a permanent fixture in our garden! The rough, dense and dark forest green leaves—with a distinctly scratchy texture on the upper page—will create a bold presence all through the year! It is a highly medicinal flowering plant, with gorgeous purple and white drooping skirts that come in late summer, to announce the warm prairie winds to you, your family and pollinators.
The spiky central cones, that turn a stunning coppery bronze, are packed with immune-boosting medicinal properties, and they are very decorative too! Indeed, the goldfinches and little winged visitors to your garden will add a spark of joy and happiness as they feast on these free bird feeders all winter long.
I can hear you… “I must add fertilizer for big blooms!” you are thinking. Do NOT do it! Rich soil makes weak floppy plants; trust the prairie! We direct sow them 1/4 inch deep and 12 to 18 inches apart. Its very unusual personality flowers which is ideal for a wild naturalistic garden of you want it. Take your pick of classic ‘Magnus’ or the jaw dropping ‘Cheyenne Spirit’ mix, but skip the super-fluffy hybrids because the bees cannot use them!
Marigold (Tagetes)
Do not listen to anyone who says these are boring! Their deeply lobed, ferny foliage is a rich, vibrant green that looks wonderfully delicate. They are absolute workhorses, exploding with velvety pom-poms of fiery red, intense orange, and golden yellow. They bloom in a lightning-fast 50 to 60 days, announcing the summer sun to you, your family and pollinators from June until frost.
The intricate, tightly rolled buds before they open look like little golden crowns, and they are very decorative too! Even so, the bees and little winged visitors to your garden will add a spark of joy and happiness. I plant them with my tomatoes EVERY year!
They are an essential companion plant because their roots release compounds that suppress harmful soil nematodes, saving you money on pest control! We direct sow the seeds 1/4 inch deep and 8-12 inches apart. Whether you choose the low-mounding French types like ‘Queen Sophia’ or the tall African ‘Crackerjack’, they are jaw dropping!
Black-Eyed Susan (Rudbeckia hirta)
If there is one classic that defines the late summer, it is this one! The dense, bright green leaves are distinctly scratchy and fuzzy on the upper page—a texture that many of us gardeners absolutely adore. They form a robust base that holds up brilliantly even when the summer humidity tries to wear them down.
By the time July rolls around, the plant bursts into a staggering display of yellow, gold, and warm-toned blooms that last all the way into October. Those jaw dropping, exquisite petals drape beautifully around chocolate-brown centers, announcing the high summer to you, your family and pollinators.
The dark central seedheads hold on tightly even as the petals fade, and they are very decorative too! Indeed, the finches and little winged visitors to your garden will add a spark of joy and happiness as they feast on the seeds in autumn. I can hear you… “But they die after two years!” you are thinking.
Yes, they are technically short-lived, but they self-seed like crazy! If you let them ripen, you will have a steady population forever, saving you money! To get started, we direct sow the seeds on the soil surface or barely cover them because they need light to germinate, spacing them about 12 inches apart. They bloom in 90 to 110 days, making them invaluable for mass plantings!
Annual Phlox (Phlox drummondii)
Unlike its tall perennial cousins, this mound-forming beauty hugs the earth beautifully. Its soft, rich green foliage is finely textured and delicate, providing a lush green carpet early in the season.
But the real show starts quickly—bursting with clusters of small, five-petaled blooms in gorgeous pinks, purples, whites, and corals! They bloom for months on end, filling the air with a deep, emotional fragrance to announce the sweet summer breezes to you, your family and pollinators.
The stunning vintage color tones—especially on varieties like ‘Cherry Caramel’ that fade from caramel to deep cherry—are utterly exquisite, and they are very decorative too! What’s more, the butterflies and little winged visitors to your garden will add a spark of joy and happiness as they follow the sweet perfume. You are lucky indeed to grow them, as they are jaw dropping as a border plant.
Since they like slightly cooler weather, May sowings work great; just direct sow them 1/8 inch deep and about 6 inches apart! They burst into flower in just 60 to 80 days, but remember our secret trick: pinch the tips when the plants are 4-6 inches tall to encourage bushier growth!
Mexican Sunflower (Tithonia rotundifolia)
Honestly, if you only plant one new flower this may, make it this one! It forms a whopping, branching structure up to 6 feet tall! The large, velvety, and intensely lush leaves—with a distinctly soft texture on the upper page—create a magnificent backdrop. While other plants flag in the August heat, this giant hits its stride!
It bursts into brilliant, bright orange daisies, announcing the late summer bounty to you, your family and pollinators. The fuzzy, thick stems have a wonderful silvery sheen to them, and they are very decorative too! What’s more, the monarchs, butterflies and little winged visitors to your garden will lose their minds over it, adding a spark of joy and happiness.
Because these get so big, we direct sow the seeds 1/4 inch deep and give them plenty of room, spacing them 18 to 24 inches apart! They take 90 to 100 days to bloom, but they don’t stop until frost. Its very unusual personality males it an invaluable secret weapon for towering back-of-border statements, but they can get top-heavy, so stake them if you are in a windy spot!
Written By
Amber Noyes
Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.