4 Perennial Flowers to Plant in Spring: Where To Plant & Care Tips

Key Takeaways

• The four best perennial flowers to plant in spring are Creeping Phlox, Black-Eyed Susan, Catmint, and Siberian Iris, each returning year after year with bloom times ranging from April through fall.

• Spring is one of the two best planting windows for perennials, alongside fall, because warming soil and consistent rainfall give roots a full growing season to establish before the first frost.

• Where you plant matters as much as what you plant: Creeping Phlox suits slopes and rock gardens, Siberian Iris thrives near ponds or low-lying wet areas, Catmint works well along pathways in lean soil, and Black-Eyed Susan adapts to hot, dry borders and meadow-style beds.

• Most of these perennials need minimal feeding and benefit from dividing every three to five years. Cutting back after the first bloom flush, as with Catmint and Creeping Phlox, often triggers a second round of flowering later in the season.

• At GS Plant Foods, our Organic Liquid Humic Acid and Fish and Kelp Liquid Blend support perennial root development and consistent blooming without overstimulating growth, and both are safe around pets and children.

What Perennial to Plant in Spring?

The four best perennial flowers to plant in spring are Creeping Phlox, Black-Eyed Susan, Catmint, and Siberian Iris. Each returns year after year without replanting, with bloom times that span from April through fall, different sun and soil requirements, and care routines that are manageable for everyday gardeners.

Spring is one of the best planting windows for perennials because warming soil and consistent rainfall give roots a full growing season to establish before the first frost. Before getting started, check your USDA Hardiness Zone, loosen the soil to at least 8 inches deep with compost worked in, space plants according to their mature spread, water deeply after planting, and mulch two to three inches around the base.

Below is everything you need to know about where to plant and how to care for each perennial flower.

Top 4 Perennial Flowers to Plant in Spring

1. Creeping Phlox (Phlox subulata)

Creeping phlox is one of the most visually dramatic perennials you can plant in spring. It blooms in April and May, producing dense mats of star-shaped flowers in shades of pink, purple, white, and lavender.

Creeping phlox stays low at 4 to 6 inches tall and spreads 2 feet or more over time. It's evergreen in many climates, meaning the foliage stays attractive even when it's not in bloom. That's a rare and valuable quality in a ground cover.

Where to Plant Creeping Phlox

Creeping phlox thrives in full sun and needs at least 6 hours of direct sunlight daily. It is a natural fit for slopes, rock gardens, and retaining wall edges where it can cascade downward. It handles poor, rocky, or sandy soil better than most perennials, and does not tolerate soggy or waterlogged conditions.

Creeping Phlox spreads up to 2 feet over time and produces dense mats of star-shaped flowers in different shades.

Creeping Phlox Care Tips

Trim back about one-third of the plant right after blooming ends in late spring. This encourages dense regrowth and often triggers a second flush of flowers. Fertilizing is rarely necessary, as too much nitrogen causes leggy growth at the expense of flowers. If the soil is extremely poor, a light application of a balanced organic fertilizer like our Fish and Kelp Liquid Blend in early spring is sufficient. Divide every 3 to 4 years to prevent the center from becoming woody and bare.

2. Siberian Iris (Iris sibirica)

Siberian iris produces elegant blooms in shades of deep violet, blue, white, and yellow from late spring into early summer, typically May through June. Its upright, grass-like foliage stays attractive all season long, well after flowers fade. It tolerates wetter soil conditions than most perennials and performs reliably across USDA Zones 3 to 8.

Where to Plant Siberian Iris

Plant Siberian iris in full sun to partial shade with consistently moist, well-drained soil. It tolerates slightly wet conditions, making it an excellent choice near ponds, rain gardens, or low spots that stay damp. Space plants 18 to 24 inches apart to allow air circulation and room for clumps to expand.

Siberian Iris forms dense, upright clumps and blooms reliably from May through June with little maintenance required.

Siberian Iris Care Tips

Water regularly during the first growing season, then reduce frequency once established. Mature plants handle short dry spells well but prefer consistent moisture. 

Cut foliage back to 4 to 5 inches in late fall after it turns brown. Every 3 to 5 years, when the center of the clump starts dying out and flowering slows, dig and divide in early fall. Replant the vigorous outer sections, and discard the woody center.

3. Catmint (Nepeta racemosa)

Catmint produces cascading mounds of lavender-blue flower spikes from late spring through summer, attracting bees, butterflies, and hummingbirds consistently. The silvery-green foliage is aromatic and deer-resistant, making it valuable in gardens where wildlife browsing is a concern. It grows 12 to 18 inches tall and wide, working well as border edging, a pathway planting, or a filler between larger perennials.

Where to Plant Catmint

Catmint needs full sun and well-drained soil and will not tolerate soggy roots. It performs better in lean soil than in rich, over-amended beds where excess nutrients push foliage growth at the expense of flowers. Plant it along walkways where brushing against the foliage releases its pleasant minty fragrance.

Catmint produces dense lavender-blue flower spikes from late spring through summer.

Catmint Care Tips

Cut catmint back by half immediately after the first flush of blooms fades, usually in midsummer. This prompts a vigorous second bloom that often continues into fall. Without this trim, the plant becomes floppy and flowering slows considerably. 

Water deeply but infrequently once established, and avoid overhead watering to prevent powdery mildew. Divide every 3 to 4 years in spring to keep clumps tight and productive.

4. Black-Eyed Susan (Rudbeckia hirta)

Black-Eyed Susan is a North American native wildflower that blooms from midsummer through fall with bold golden-yellow flowers and dark brown centers. 

It is drought-tolerant, heat-resistant, and bridges the gap between spring and fall bloomers, adding color when many spring perennials have already faded. It self-seeds freely and will spread naturally through garden beds over time.

Where to Plant Black-Eyed Susan

Black-Eyed Susan performs best in full sun with at least 6 to 8 hours of direct light daily. It adapts to a wide range of soil types, including clay, loam, and sandy soil, as long as drainage is reasonable. 

It works well on hot, dry slopes, meadow-style plantings, or mixed borders. Space plants 18 to 24 inches apart for air circulation and natural spreading.

Black-Eyed Susan self-seeds freely and spreads naturally over time.

Black-Eyed Susan Care Tips

Water during extended dry spells in the first season, then reduce frequency once established. Avoid rich, heavily fertilized soil as it blooms more prolifically in leaner conditions. 

Cut plants back to a few inches above the ground in late fall or early spring. Leaving seed heads standing through winter provides a food source for birds, particularly goldfinches.

4 Perennial Flowers to Plant in Spring: Summary Table

Keep Your Perennial Flowers Healthy with GS Plant Foods

Creeping Phlox, Siberian Iris, Catmint, and Black-Eyed Susan each offer something different, from early ground cover to bold midsummer color. Getting the planting location right and giving roots time to establish in spring sets the foundation for years of reliable blooming.

That foundation starts with healthy soil. At GS Plant Foods, our Liquid Humic Acid and Fish and Kelp Liquid Blend support perennial root development and consistent blooming, and both are safe around pets and kids. Browse our flower fertilizer collection to see what fits your garden.

Check out our collection today!

Frequently Asked Questions (FAQs)

What is the easiest perennial flower to grow in spring?

Black-Eyed Susan is widely considered the easiest spring perennial to grow. It tolerates poor soil, drought, heat, and neglect better than almost any other flowering perennial. Catmint is a close second, adding the bonus of deer resistance and a bloom season that can stretch into fall with one midseason trim.

How long do spring perennials stay in bloom?

Bloom duration varies by species, which is why mixing varieties with different bloom times matters for a garden that looks good all season. Creeping Phlox blooms for four to six weeks in mid-spring, Siberian Iris for three to four weeks in late spring, and Black-Eyed Susan for ten to twelve weeks from midsummer through early fall. Catmint produces the longest window, up to 4 months across 2 flushes, when cut back after the first bloom.

Do spring perennials grow well in pots or containers?

Catmint, Creeping Phlox, and Black-Eyed Susan all perform reasonably well in containers, provided pots are at least 12 to 16 inches deep to give roots enough room to develop. Container perennials need more consistent watering and feeding than in-ground plants since the soil dries out faster and nutrients deplete more quickly. In colder climates, move pots into an unheated garage or shed during winter to protect roots from freeze-thaw cycles.

How do you know when a perennial needs to be divided?

The clearest sign is a dead or bare center in an otherwise healthy clump, which means the plant has exhausted the nutrients beneath its oldest roots. Other signals include a noticeable drop in flowering, stems that flop rather than stand upright, or clumps that have outgrown their space and crowd neighboring plants. Most perennials benefit from division every three to five years in early spring or early fall.

Which GS Plant Foods products are best for perennial flowers?

At GS Plant Foods, our GS Plant Foods Organic Liquid Humic Acid is the strongest starting point for perennial beds, as it improves soil structure and nutrient availability from the ground up. For bloom support, our Flower Power blend uses organic fish, kelp, and ocean plant extracts to encourage bigger, brighter flowers. For ongoing seasonal feeding, our Fish and Kelp Liquid Blend rounds out the routine with a balanced organic boost. All three are pet and kid-safe.

*Disclaimer: This information is for educational purposes only. Always follow product label instructions and consult with qualified professionals for advice specific to your region, climate, and growing conditions. Individual results may vary based on environmental factors, soil conditions, plant species, and care practices. For specific product recommendations and application rates, visit GS Plant Foods.