Late May isn’t too late — if you choose the right plants. While some annuals need an early start to shine, others are quick to germinate, fast to bloom, and perfectly suited for planting as summer approaches.
In this article, we’ll spotlight 10 fast-growing annuals that you can confidently sow or transplant right now for colorful, vibrant results within weeks. Plus, we’ll cover 8 varieties that are best saved for next year, since planting them now would likely mean disappointing growth or delayed blooms.
Plant smart this May — and still enjoy a gorgeous summer display.
Sunflowers
Imagine a landscape transformed by the towering presence of sunflowers, their cheerful faces always turned towards the sun. These fast-growing giants thrive when planted in late May, quickly establishing themselves in sunny spots. With minimal care, they promise an impressive display within weeks.
Varieties can range from classic yellow giants to more exotic colors, offering versatility in garden design. Sunflowers also support local wildlife, attracting bees and birds with their seeds.
Whether used as a backdrop or focal point, they bring a bold statement with an easygoing charm. Perfect for any garden enthusiast looking to make an impact.
Zinnias
Zinnias bring a splash of color that few can resist, thriving in the late spring warmth. By planting them now, expect blooms in a dazzling array of colors reminiscent of a painter’s palette.
These robust annuals stand out for their ease of care and resilience, making them ideal for beginners and seasoned gardeners alike. Zinnias’ long-lasting flowers can grace garden beds or become delightful cut flowers for indoor decor.
Their diversity in size and color can complement any garden theme, ensuring they remain a favorite. A little care rewards with endless vibrant displays throughout summer.
Marigolds
Bursting with vibrant hues, marigolds are the unsung heroes of the late May planting list. Known for their striking orange and yellow petals, these annuals are not just beautiful but practical too.
Their natural pest-repelling properties make them a gardener’s ally, providing both beauty and protection. Within a short span, marigolds establish themselves, bringing warmth and brightness to any garden space.
Their versatility makes them suitable for borders, containers, or companion planting with vegetables. With little effort, they become a staple of summer gardens, adding life and color.
Cosmos
Cosmos are the epitome of effortless beauty, their delicate petals dancing in the breeze. They thrive in the warmer climates of late spring, making them an excellent choice for May sowing.
These elegant blooms come in soft shades of pink and white, adding a touch of romance to any garden. Their airy structure complements both formal and informal garden settings.
Once established, cosmos are remarkably low maintenance, requiring minimal water and care. They attract butterflies, enhancing the garden’s biodiversity while providing endless charm through summer months.
Nasturtiums
Nasturtiums are a gardener’s delight, with their edible flowers bringing both color and flavor. Late May is an ideal time to plant these fast-growing beauties, known for their vivid orange and red blooms.
Their trailing habit makes them perfect for hanging baskets or as ground cover, offering versatility in gardening layouts. Nasturtiums thrive in poor soil, making them low-maintenance yet rewarding.
Aside from visual appeal, they act as a natural pest deterrent, attracting beneficial insects. Their peppery-tasting flowers double as a decorative and tasty addition to salads.
Petunias
Petunias are synonymous with summer, their cascading flowers creating a vibrant display. By planting them in late May, gardeners can enjoy their blooms through the warmer months.
These annuals come in an array of colors from soft pastels to bold, vibrant shades, offering endless design possibilities. Petunias are perfect for hanging baskets, window boxes, or borders, adding a burst of color wherever planted.
They require regular watering and full sun for optimal growth, rewarding gardeners with continuous flowers. Their charm and versatility make petunias a perennial favorite in summer gardening.
Morning Glories
Morning glories are the early risers of the garden, opening their delicate blooms with the sun. Planting them in late May ensures they quickly establish and begin their upward journey.
Their trumpet-shaped flowers come in dreamy blues and purples, perfect for covering trellises or fences. Morning glories thrive in sunny locations, with their tendrils reaching skyward.
They bring a sense of nostalgia and charm, reminiscent of old-fashioned gardens. Although short-lived, their blooms refresh daily, adding a dynamic element to garden spaces. Ideal for adding height and interest.
Calendula
Calendulas, often called “pot marigolds,” are a boon for gardeners seeking vibrant blooms. Their sunny orange flowers are not only beautiful but possess healing properties.
Planting them in late May guarantees a quick start, with blooms that offer both visual delight and medicinal uses. Calendulas thrive in most soil types, requiring minimal fuss.
They work well in borders or as part of an edible garden, with petals that can be used in teas or salads. Their cheerful presence enlivens any garden space, making them a multifunctional favorite.
Balsam
Balsams are the secret stars of shaded gardens, their vibrant hues lighting up darker corners. Planting them in late May allows them to flourish, bringing color where it’s often lacking.
These annuals boast flowers in shades of pink and purple, adding a whimsical touch to garden nooks. Their preference for shaded areas makes them versatile companions in varied landscapes.
Balsams are easy to grow, requiring little more than moist soil and occasional care. Their ability to thrive in less sunny spots makes them a valuable addition to diverse gardening efforts.
Four O’Clocks
Named for their unique blooming time, Four O’Clocks are a delightful garden addition. Planting them in late May ensures they open their vibrant petals just as the day cools.
These flowers come in an assortment of hues, from pinks to yellows, creating a lively display. They are drought-tolerant and thrive with minimal care, perfect for busy gardeners.
Their ability to bloom repeatedly adds dynamic color throughout the season. Four O’Clocks are ideal for borders or containers, offering evening charm and allure to garden spaces.
Larkspur (Missed)
Larkspur’s towering spikes of blue and purple are a sight to behold, but their planting window closes before late May. These early bloomers prefer cooler soil, needing a head start to shine.
Gardeners who miss this window miss out on a dramatic display of color and height. Larkspur’s tall, elegant blooms are perfect for adding vertical interest in early spring gardens.
Planning ahead ensures these beauties grace your garden, offering a standout floral show. Those who missed this planting opportunity should mark their calendars for next year to enjoy these elegant spires.
Snapdragons (Missed)
Snapdragons captivate with their playful, dragon-shaped blooms, but their planting time is best early in the season. Late May is too late for these charmers to thrive.
Their vibrant colors and unique petal formations make them a beloved choice for adding whimsy to any garden. Snapdragons prefer cooler temperatures to establish strong roots.
Missing the planting window means missing out on their delightful presence, but planning ahead can ensure they become a garden staple. Their absence in late May gardens is a reminder of the importance of timing in planting.
Sweet Peas (Missed)
Sweet peas offer fragrance and delicate beauty, but they require an earlier start than late May. These climbers need cooler conditions to flourish.
Gardeners who missed planting sweet peas miss out on their intoxicating scent and soft pastel blooms. Their ability to twine and climb adds vertical interest and charm to early spring gardens.
Those wishing to enjoy sweet peas should plan for early planting, ensuring these fragrant flowers have the cool temperatures they need. Their absence highlights the importance of timely planting for seasonal enjoyment.
Pansies (Missed)
Pansies are cherished for their cheerful “faces,” but late May is too late for them to start. These cool-weather favorites need an earlier planting to show their best.
Ideal for early spring gardens, pansies offer a range of colors and patterns. Their hardy nature endears them to gardeners seeking early-season blooms.
Missing the planting window means missing their vibrant hues, but planning for next season can ensure they brighten your garden. Their endearing faces are a symbol of early spring’s promise, best enjoyed with careful timing.
Violas (Missed)
Violas, with their charming blooms, are a springtime favorite, but late May is past their prime planting time. These small but mighty flowers need cooler conditions to thrive.
Gardeners missing the window for violas lose out on their long-lasting blooms and delightful colors. Ideal for borders or containers, they bring early-season joy.
Planning ahead ensures violas can grace your garden with their cheerful presence. Their absence in late May serves as a reminder of the fleeting nature of ideal planting times, encouraging early preparation.
Poppies (Missed)
Poppies, with their iconic red blooms, are a gardener’s dream, but late May is too late for planting. These hardy flowers favor an early spring start.
The missed opportunity to plant poppies in time means missing their iconic color and delicate petals. These blooms offer a striking visual impact, perfect for drifts or borders.
Early planning can ensure poppies find their place in the garden, offering vibrant displays. Their absence underscores the importance of timely action, ensuring these beauties have the conditions they need to flourish.
Dusty Miller (Missed)
Dusty Miller isn’t known for blooms, but its silvery foliage adds texture and contrast. However, late May is too late to start this cool-weather favorite.
Missing the planting window means missing out on its unique leaves that complement other flowers. Dusty Miller thrives in cooler conditions, offering a striking backdrop.
Planning for early planting ensures this plant’s distinctive foliage adds interest to your garden. Its absence in late May highlights the importance of anticipating seasonal needs, allowing for diverse and textured garden designs.