May is an ideal month to enhance your garden with vibrant perennials. While many people opt for pre-grown plants from garden centers, starting perennials from seed can be a more economical choice.
This month presents a great opportunity to sow perennial seeds. For just the cost of seeds and some compost, plus a little patience, you'll be rewarded with beautiful blooms that return year after year.
If you're looking for budget-friendly ways to create stunning flower beds filled with color and attracting wildlife, this article showcases the top perennials to plant in May.
7 Perennials to Plant in May
Incorporating these perennials into your flower beds will not only add lasting color and texture but also attract pollinators and beneficial insects.
1. Agastache
Agastache, or anise hyssop, is a fragrant perennial that forms mounds and produces spikes of flowers loved by hummingbirds along with aromatic leaves.
Part of the mint family, it requires minimal care, thriving with little watering and no need for deadheading. You can sow the seeds directly in their growing spot after the last frost, although germination is often more successful when started indoors. Press the seeds into pots with seed compost but leave them uncovered since they need light to sprout.
Seeds sprout quickly at 60-65°F, and you can transplant them into your beds next month for years of delightful foliage and blooms that attract pollinators.
2. Black-eyed Susan
Black-eyed Susans are native wildflowers with striking daisy-like blooms featuring dark centers, thriving in US hardiness zones 3-11, making them an excellent choice for a wildlife-friendly garden. While the classic yellow variety is popular, you can find unique colors like green, red, and multi-colored options.
For best results, start black-eyed Susan seeds indoors in spring or sow them directly in the garden when soil temperatures reach around 70°F, often in May. Scatter the seeds or plant them in rows spaced 12 inches apart, covering lightly with soil. Keep the soil moist for optimal germination and thin seedlings to 12-30 inches apart based on their expected size.
3. Catmint
Catmint, also known as nepeta, is a fragrant perennial that blooms for an extended period. With proper care, you can enjoy its lovely lilac flowers from spring to fall. Pruning after the first blooms will encourage additional flowers throughout the season.
Sow catmint seeds directly in May in a sunny, well-draining area. Plant seeds a quarter-inch deep in a moist seedbed, covering lightly with soil. Keep the area moist and thin seedlings to 12 inches apart when they reach a few inches tall. In smaller spaces, catmint can thrive in pots, providing silver-green foliage and lilac blooms adored by bees and butterflies.
4. Foxglove
Foxgloves are biennials or short-lived perennials that produce impressive flower spikes in early summer. Even biennial varieties self-seed readily, giving the impression of being perennials.
You can sow foxglove seeds indoors or directly outside in May. For indoor sowing, sprinkle seeds on the surface of pots filled with seed compost, placing them in a warm, bright area with temperatures between 64-75°F. Once they germinate, they can be transplanted in fall.
Alternatively, sow seeds outdoors where they will bloom, covering them lightly and keeping the soil moist. Thin seedlings when they grow a few inches tall to allow room for development, and expect blooms the following year.
5. Gaillardia
Gaillardia, or blanket flower, is a striking perennial perfect for borders and one of the quickest flowers to grow in spring. Expect large, vibrant blooms in shades of orange, red, yellow, and white, lasting well into summer and fall.
You can start seeds indoors in May, germinating them on a windowsill, but remember to leave them uncovered for light. Alternatively, sow seeds directly in the flower bed by scattering them on the surface and keeping them moist for successful germination.
Gaillardia is also drought-resistant once established, continuing to bloom without regular deadheading.
6. Lupines
Lupines are cherished for their stunning flower spikes that bloom in late spring to early summer.
You can sow perennial lupines in late spring for blooms next year, though expect a variety of colors rather than a uniform plant. For specific varieties, propagate from cuttings instead of seeds.
It's advisable to soak seeds before planting or scarify them to aid germination. Sow directly outdoors in their final location, planting seeds a half-inch deep and covering lightly with compost while keeping the soil moist.
7. Sneezeweed
Sneezeweed, or helenium, stands out as an excellent fall-blooming perennial, adding warm tones of orange, red, or yellow to your garden. These tall plants can start blooming within the first year of sowing.
For best results, begin seeds indoors in May by placing them on the surface of seed compost, covering only lightly. Germinate in a cold frame or on a windowsill at temperatures of 55-60°F, moving seedlings outdoors once they reach a few inches tall.
Space plants at least 12 inches apart and hope for blooms to grace your garden in August or September.
Shop for Perennials to Plant in May
Consider sowing these seeds for colorful additions:
- Mixed Color Foxglove Seeds: Grow plants adorned with stalks of lavender, rose, cream, fuchsia, and ivory.
- Blue Moon Catmint Seeds: This perennial produces large lavender-hued flower spikes with a hint of white.
- Arizona Sun Agastache Seeds: A frost-hardy variety featuring stunning canary yellow tubular blooms.
Additionally, while planning your garden with perennials to plant in May, consider sowing annuals this month for vibrant summer displays. Check out our guides for annual flowers and climbers to plant in May for more inspiration.
