Perennials are the workhorses of the garden — they return year after year, often with even more vigor than before. But not all perennials are slow growers. Some double or even triple in size in a single season, quickly filling in bare patches, covering up unsightly areas, or creating lush, colorful borders.
Whether you’re starting a new garden or refreshing an old one, here are 15 fast-spreading perennials that grow explosively, plus 5 perennials that give instant visual impact right out of the gate.
15 Perennials That Triple in a Season
These plants grow rapidly, making them ideal for covering ground, filling borders, and giving your garden a lush, mature feel in just one season.
1. Catmint (Nepeta)
- Growth Rate: Rapid
- Best For: Pollinator gardens, borders
- Why It Spreads: Vigorous root system and self-seeding
- Bonus: Drought-tolerant and deer-resistant
2. Black-Eyed Susan (Rudbeckia)
- Growth Rate: Very fast
- Best For: Cottage gardens, mass plantings
- Why It Spreads: Self-seeds readily and forms clumps quickly
3. Coneflower (Echinacea)
- Growth Rate: Fast
- Best For: Pollinator gardens, mixed borders
- Why It Spreads: Strong clumping and self-seeding
4. Bee Balm (Monarda)
- Growth Rate: Explosive
- Best For: Wildflower gardens, attracting hummingbirds
- Why It Spreads: Rhizomes allow for quick colony formation
5. Yarrow (Achillea)
- Growth Rate: Spreads aggressively
- Best For: Low-maintenance and dry gardens
- Why It Spreads: Underground rhizomes and self-seeding
6. Shasta Daisy (Leucanthemum x superbum)
- Growth Rate: Fast-growing clumps
- Best For: Borders, cut flower gardens
- Why It Spreads: Seeds and divisions grow quickly
7. Coreopsis
- Growth Rate: Fast-growing and spreading
- Best For: Sunny beds, dry gardens
- Why It Spreads: Abundant reseeding and spreading habit
8. Russian Sage (Perovskia atriplicifolia)
- Growth Rate: Rapid
- Best For: Dry, sunny areas
- Why It Spreads: Woody base and sprawling stems expand quickly
9. Lamb’s Ear (Stachys byzantina)
- Growth Rate: Spreads fast by stolons
- Best For: Ground cover in hot, dry spots
- Why It Spreads: Low-growing, spreads horizontally
10. Blanket Flower (Gaillardia)
- Growth Rate: Fast to fill gaps
- Best For: Hot, sunny borders
- Why It Spreads: Reseeds and establishes clumps quickly
11. Mountain Mint (Pycnanthemum)
- Growth Rate: Aggressive
- Best For: Pollinator beds, herb gardens
- Why It Spreads: Rhizomatous growth
12. Daylilies (Hemerocallis)
- Growth Rate: Rapid clump formation
- Best For: Borders, mass planting
- Why It Spreads: Tuberous roots expand quickly
13. Obedient Plant (Physostegia virginiana)
- Growth Rate: Wildly fast
- Best For: Meadow gardens, rain gardens
- Why It Spreads: Aggressive rhizomes
14. Gooseneck Loosestrife (Lysimachia clethroides)
- Growth Rate: Can take over quickly
- Best For: Contained beds
- Why It Spreads: Rhizomes expand underground
15. Joe Pye Weed (Eutrochium purpureum)
- Growth Rate: Tall and wide within one season
- Best For: Rain gardens, back borders
- Why It Spreads: Forms large clumps and reseeds easily
5 Perennials for Instant Impact
These plants may not triple in size, but they look stunning the moment you plant them and grow steadily each year.
1. Hosta
- Instant Appeal: Big, bold foliage in many textures and colors
- Ideal Use: Shade gardens, foundation plantings
2. Coral Bells (Heuchera)
- Instant Appeal: Colorful, evergreen leaves and airy flower spikes
- Ideal Use: Front of borders, shade beds
3. Japanese Forest Grass (Hakonechloa)
- Instant Appeal: Graceful, arching golden blades
- Ideal Use: Underplanting, edge accents
4. Lupine (Lupinus)
- Instant Appeal: Tall, spiky blooms in early season
- Ideal Use: Cottage gardens, vertical accents
5. Peony
- Instant Appeal: Lush, romantic blooms in spring to early summer
- Ideal Use: Feature plant or cutting garden star
Pro Tips for Managing Fast-Growing Perennials
- Divide regularly to control spread and keep plants healthy.
- Mulch heavily to suppress unwanted seedlings.
- Pair fast growers with well-behaved perennials to maintain balance.
- Use containers or edging for aggressive spreaders like Bee Balm or Gooseneck Loosestrife.
Final Thoughts
Fast-growing perennials can turn a bare garden into a thriving paradise in just one season. Whether you’re looking for long-term performers that multiply like magic or stunning instant-impact stars, there’s a perennial for every garden vision.
