As May approaches, I'm excited to fill my pots and containers with blooms that guarantee vibrant color throughout the summer. While perennials are lovely, I find annuals and climbing plants bring a lively spirit to my garden.
A staple in my planting each year is Thunbergia, also known as the black-eyed Susan vine. I love to grow this climber in small pots near the patio, where its bright yellow flowers with dark centers attract bees. Despite trying many different flowers, Thunbergia is always a winner. You can start it from seed in May, with blooms appearing from July until fall. Amazing, right?
If you're eager for bold and cheerful blooms this summer, here are some of my favorite flowers to plant in containers this May. These selections are easy to grow and wonderfully vibrant—perfect for any outdoor space.
5 Container Flowers to Plant in May – My Favorites
For those seeking colorful blooms for pots, the options are endless. Whether you prefer compact, fast-growing annuals or striking climbers, there's something for everyone.
Container gardening should be adventurous; pots allow you to experiment freely. Here are five flowers I love to grow year after year.
1. Chianti Sunflowers
Sunflowers might seem challenging to grow in pots, especially with larger varieties reaching up to 10 feet tall. However, I often choose dwarf sunflowers like the 'Chianti Hybrid'.
With its stunning maroon hue, this variety stands at about four to five feet, making it ideal for smaller spaces or balconies.
To grow sunflowers, place your pots in sunny areas and ensure they're well-watered and fed throughout the summer. I've seen them bloom well into fall, so remember to deadhead regularly to extend their flowering period, if possible.
Order 'Chianti' sunflower seeds from Burpee now; they can be sown directly in May.
Plant seeds about half an inch deep, ideally in groups of 2 to 3 per container. Expect germination in about 10 days.
2. Sweet Alyssum
If you want low-maintenance plants, sweet alyssum is a fantastic choice. These tiny, fast-growing flowers may not be towering, but they add a lovely cascading effect to container edges.
This low-growing annual reaches about four inches tall, making it great alongside taller perennials like verbena or coneflower.
There are many varieties, including peach, red, or white blossoms. For a cool touch, try 'Royal Carpet' alyssum seeds from Walmart. Deep purples and blues look stunning with lush foliage plants like hostas and ferns.
Sow seeds directly in pots during May in a sunny spot, although they'll tolerate some shade. If planted this month, expect blooms from July to October.
3. Thunbergia
In my experience, the black-eyed Susan vine, or Thunbergia alata, is one of the easiest vines to cultivate. I often grow it in pots by seating areas for everyone to admire its bright flowers.
This fast-growing vine prefers full sun and can reach six feet in a season, perfect for adding vertical interest to small gardens. Plus, it attracts hummingbirds with its nectar-rich blooms.
In warmer areas (US hardiness zone 10 and above), this vine is perennial, while in cooler regions, treat it as an annual. It's simple to grow from seed each spring.
Get mixed seeds of Thunbergia alata online from Burpee and sow them in containers in April or May after the last frost. Expect flowers in 8 to 10 weeks after germination.
4. Cypress Vine
Cypress vine, or Ipomoea quamoclit, is among the quickest-growing flowers for spring planting. This sun-loving plant thrives in hot weather.
Its fern-like foliage pairs beautifully with red or white starry flowers that bloom from July through September.
Be cautious, as the Cypress vine can grow up to 10 feet in a season and may self-seed aggressively, becoming invasive in some areas. Always check local guidelines before planting.
Order Cypress vine seeds from Burpee. I like to sow them in larger pots in May, with flowers appearing in about 60 days.
Provide support like a trellis for the vines to climb. For smaller spaces, a portable wooden trellis with a planter from Amazon works great.
5. Mexican Sunflower
Tithonia, or Mexican sunflowers, are tall perennial flowers well-suited for deeper pots. I've grown them in hot borders and patio pots, showcasing their vibrant blooms.
This is an excellent choice for a cut flower garden in pots, as their longer stems are perfect for arrangements.
Sow seeds directly into deep pots or raised beds in May when temperatures are above 60°F (15°C). Germination takes about 10 to 14 days, with flowers appearing in roughly 10 weeks.
Native to Mexico, Tithonia loves full sun and is drought-tolerant once established, although regular deep watering promotes more blooms.
Staking taller varieties early prevents wind damage. I've successfully grown the 'Torch' variety from Amazon, featuring rich orange flowers and growing to about 4 feet tall—great for adding drama to your container displays.
Remember to keep your container gardens well-watered throughout spring and summer, as pots can dry out quickly in warm weather. Morning or evening watering is best when temperatures are cooler.
Shop Your Container Flower Kit
These dwarf 'Teddy Bear' sunflower seeds can be planted in May and will bloom later in summer, reaching three-foot stems.
This versatile garden structure is perfect for your annual vines to climb, creating instant privacy in your yard.
This 'Myrtlewood Planter' features a subtle etched design, looking stunning when filled with colorful annuals and vines.
