10 Beautiful Flowers To Plant In Containers In May For Seasonal Color

May feels like that turning point moment when summer starts to peek around the corner. It's officially spring, sun is finally out for long hours at a time, temperatures start to climb, and pollinators get busy. May is that sweet spot in spring when the garden starts to shift into summer mode, and it's the perfect time to start planting flowers for a season full of color and fragrance.

With frost out of the picture, soils warming up, and brighter days, flowers have everything they need to bloom. And if you're envious of those sprawling English cottage gardens or wildflowers growing on trellises, but don't have the space for it, don't worry. You can grow stunning blooms in containers, too. Whether you're working with pots or raised garden beds, container planting is absolutely compatible with gorgeous flower gardens. It can bring color to your backyard, balcony, patio, deck, or front yard, no matter how small or big.

The key is to pick the type of flowers that can grow healthy and happy in containers, and there are tons. In fact, container planting allows you to grow flowers that have different sun and soil requirements. For example, place a container full of petunias in a sunny corner of your yard, and begonias in a shady spot. You can also fill each individual pot or container with a different soil mix to adapt to each plant's needs. This also allows you to keep soils at different moisture levels. That way, you can keep sunflowers happy and watered once a week, next to the lavender plants you only water every fortnight.

Petunias (Petunia) are one of the popular flowering annuals that you can plant in May for stunning blooms all the way until temperatures drop again and frost comes to bite. These are really simple flowers to grow, and they do wonderfully well in containers placed in full sun. As soon as May rolls around, purchase small petunia plants at the garden store (or even Walmart) and transfer them into containers. This timing works across the United States, though you could even start around mid-April in zones 6 to 8. 

Geraniums ( Pelargonium x hortorum) don't just tolerate being grown in pots and containers, they actually thrive in that environment. In order to grow outdoor geraniums, make sure to get them into their pots and planters in May. That way, they'll get comfortable just in time to bloom and give you colorful flowers until the fall. For this, you can buy geranium plants and transfer them to a container filled with well-draining soil, placed in direct sunlight. 

Another option for potted flowering plants are marigolds (Tagetes). Here, be careful which type of marigold you're working with. Some species, like African marigolds (Tagetes erecta), are especially large and therefore require deeper pots and longer grow times. If planting in May, you can focus on smaller species, which don't need as much time to reach their full mature size and can start blooming in time. For example, May is the perfect time to plant French marigolds (Tagetes patula) or signet marigolds (Tagetes tenuifolia), which are smaller and can be planted between spring and summer. Here again, opt for full sun. 

Begonias (Begonia) are another type of flower that loves to grow in containers. The ideal time for planting begonias is on the warmer side of spring, when soil temperatures consistently reach 60 degrees Fahrenheit. Depending on where in the United States you are located, this can happen as early as May. If you live in a cooler area, monitor soil temperatures, and hold until early June if needed. Despite liking the warmth, these guys don't enjoy direct sun. Therefore, place the container in a shaded spot where they'll get indirect sunlight or morning light only. 

Impatiens (Impatiens walleriana) are one of those flowering plant that doesn't require a ton of work and does very well in containers, pots, and garden beds. One 12-inch pot can house several plants, which you can purchase at the store in various bright colors. A perfect time for these beauties is spring, once there is absolutely no risk of frost left, around early May. Depending on where you live, the exact timing might need adjustment, so make sure to monitor local climates or ask a local garden center for advice. 

Zinnias (Zinnia elegans) are stunning flowers that are full of color, layers, and dimension. They're not especially fragrant, making them a good option for gardeners who are sensitive to strong smells. You can grow them from seed if you start in May, which should lead to blooms in the summer. These beauties can grow in containers, but they need a bit of space. For full-size varieties, use containers that are at least 12 inches deep. If you can find dwarf varieties (like Zinnia elegans 'Thumbelina'), you can go a bit more shallow (8 to 12 inches).

If you like the idea of planting flowers from seeds, another fantastic option for May sewing are sunflowers (Helianthus annuus). Because of their size, sunflowers can be a bit intimidating, but they're actually really easy to grow. Plant them pots or containers that are 12 to 18 inch deep in a bright, sunny spot. Each sunflower takes 11 to 18 weeks to bloom, after which is should live 2 to 3 weeks. Therefore, you can stagger seeding by a few weeks to ensure you'll have plenty of healthy flowers all summer long.

Cosmos (Cosmos bipinnatus) are often planted directly in the ground, especially for perfect cottage garden and meadow-style backyard. But these little flowers are actually fairly adaptable, and they can grow in containers too. Here, look for containers that are between 8 and 15 inches deep (shorter for small varieties, deeper for taller ones). Cosmos can be grown from seeds or from small transplants once the last frost has passed. In zones 3 and 4, that should be around mid-May. If you live in warmer parts of the United States, you can start a bit earlier.

Sweet Alyssum (Lobularia maritima) is known for its many tiny little flowers that add so much brightness and charm to a garden. These are often used as whimsical ground cover plants for yards, but they're also perfect for container growing. They grow thick with flowers and overflow gracefully over on the edges of the container. You can plant these flowers in May from seeds, ideally placing the container in a sunny corner of your yard or patio. While they like the sun, they don't love heat, so summer growing is best suited for northern states. 

May is also the perfect time to bring more pollinators to your garden by growing lavender (Lavandula angustifolia). And while this is often thought of as a herb, it's unmistakably a flower, too. This fragrant plant should, ideally, be planted in the spring once frost is behind you. Typically, this makes May a great choice, though it depends on the exact climate of your area. Plus, planting lavender in a container instead of the ground is a great way to keep the plant happy by monitoring moisture levels and avoiding overwatering.