You’ve dreamed of a low-maintenance perennial garden, but some plants that sound beautiful and easy turn into garden nightmares. These problematic perennials multiply out of control, require constant pruning, attract pests, or spread so aggressively they choke out your other plants. Understanding which perennials to avoid before you plant them can save you years of frustration, expensive removal costs, and the heartbreak of destroying plants you actually like.
Understanding Problematic Perennials: 7 Plants to Reconsider
Not all perennials deserve a place in your garden. These seven commonly planted perennials have significant downsides that gardeners often discover too late.
Key Problem Categories
- Aggressive spreaders – plants that escape their designated beds and invade neighboring areas through underground runners or prolific self-seeding
- High-maintenance bloomers – perennials requiring frequent deadheading, staking, or pruning to look presentable throughout the season
- Pest and disease magnets – plants susceptible to powdery mildew, spider mites, or other issues that quickly affect nearby plants
- Invasive colonizers – plants that develop such dense root systems they prevent other plants from establishing nearby
- Short-lived or unreliable – perennials that decline rapidly, require division every season, or fail to return reliably in many climates
The 7 Problematic Perennials Explained
Mint – The Underground Invader
Mint seems innocent when you plant it, but its aggressive underground runners will colonize your entire garden bed within two seasons. It spreads faster than you can control and nearly impossible to eliminate once established. Plant only in containers if you want mint’s culinary benefits without the headache.
Butterfly Bush – The Maintenance Burden
While butterfly bush attracts pollinators and produces gorgeous blooms, it requires obsessive deadheading to stay attractive. Without constant pruning and spent flower removal, it becomes leggy and overgrown. In warm climates, it also self-seeds prolifically and can become invasive.
Daylilies – The Overcrowded Competitor
Daylilies develop such thick, dense clumps that nothing else can grow nearby. They also attract spider mites and other pests that spread to surrounding plants. Their aggressive rhizomes make them difficult to remove once you change your mind about them.
Bee Balm – The Powdery Mildew Magnet
Bee balm consistently develops powdery mildew in most regions, especially in humid climates or crowded garden beds. The disease spreads to nearby plants and makes the foliage look diseased all season. Even disease-resistant varieties often struggle in less-than-ideal conditions.
Delphinium and Larkspur – The Fussy Bloomers
These tall perennials require extensive staking to stay upright and need constant deadheading to produce repeat blooms. They’re also short-lived in many climates, declining after 2-3 seasons. They attract slugs and snails that can completely defoliate plants overnight.
Coreopsis – The Self-Seeding Problem
Coreopsis produces so many seeds that volunteer seedlings pop up everywhere, crowding out intentional plantings. You’ll spend entire summers removing unwanted plants that started from last year’s flowers. The constant weeding defeats the purpose of having low-maintenance perennials.
Ornamental Grasses – The Spreading Nightmare
Certain ornamental grasses like miscanthus and ravenna grass spread aggressively through rhizomes and self-seeding. They’re nearly impossible to eliminate once established and will eventually overtake surrounding perennials. Check your specific variety carefully before planting.
- Research before planting: check your USDA hardiness zone and regional invasiveness lists–a plant may be invasive in your area but not others
- Choose cultivated varieties labeled as non-spreading or sterile when available–modern breeding has produced better alternatives to the old problematic selections
- Plant questionable perennials in containers or heavily enclosed beds where you can manage their spread without affecting the rest of your garden
What to Look For When Selecting Garden Perennials
- Plant Spread Characteristics: Look for plants described as ‘clumping’ rather than ‘spreading’ or ‘rhizomatous.’ Check mature width on plant tags and garden references to ensure the plant won’t outgrow its space or overwhelm neighbors.
- Disease Resistance Ratings: Choose varieties explicitly bred for disease resistance, especially if you’re considering plants prone to powdery mildew or rust. Look for cultivars with improved genetics over older heirloom varieties.
- Maintenance Requirements: Honest plant descriptions will specify if deadheading improves appearance or is required for rebloom. Avoid plants that require weekly pruning, constant staking, or frequent division unless you genuinely enjoy that level of garden work.
- Seed Production and Self-Seeding: Research whether the variety self-seeds prolifically or stays contained. Sterile or seed-free cultivars are available for many popular perennials and eliminate constant volunteer removal.
Timber Creek Garden Edging Borders with Landscape Fabric
Best for: Containing aggressive spreaders like mint and ornamental grasses
Heavy-duty galvanized steel edging creates physical barriers that stop underground runners and rhizomes from escaping their designated beds. The included landscape fabric prevents seeds from falling into adjacent areas and blocks some root spread. This system works for both aggressive existing plantings and as a preventive barrier when planting questionable perennials. Installation takes an afternoon and provides years of protection for surrounding beds.
Check Current Price on Amazon →Burpee Tomato & Vegetable Plant Labels with Weatherproof Marker
Best for: Identifying and tracking problematic perennials you’re testing
Before you commit perennials to your garden permanently, track them with durable plant markers. This kit includes 50 waterproof labels and weather-resistant markers so you can record plant names, planting dates, and any issues you observe. Helps you document which plants became problematic in your specific garden conditions and climate. Essential for learning from mistakes and making better future choices.
Check Current Price on Amazon →Fiskars PowerGear Bypass Pruning Shears
Best for: Managing high-maintenance perennials that require constant deadheading and pruning
If you keep a problematic perennial because you love it despite maintenance needs, quality pruning shears make the work manageable. These shears feature a gear mechanism that increases cutting power without requiring hand strength, staying sharp through hundreds of cuts. The ergonomic design reduces hand fatigue during repetitive deadheading sessions. While sharp tools don’t eliminate maintenance, they make it quick enough that you might actually keep up.
Check Current Price on Amazon →Suncast Container Planter with Saucer – Extra Large 24 Inch
Best for: Growing aggressive spreaders like mint safely in contained systems
Contain your mint addiction and other spreaders in an oversized container where you control the plant completely. This 24-inch planter provides ample root space for vigorous growers while the integrated saucer catches excess water. Drainage holes prevent root rot while the solid sides eliminate any possibility of rhizomes or runners escaping. Position on a patio or deck where the plant can’t establish anything beyond its container walls.
Check Current Price on Amazon →Making Peace with Your Garden Choices
The gardeners who regret their perennial choices aren’t lazy or uninformed–they simply didn’t know better when making their initial selections. Every experienced gardener has ripped out plants they later realized were mistakes. The good news is that avoiding these seven problematic perennials saves you years of frustration. Research your choices, understand growth habits, and be honest about how much maintenance you’ll actually perform. Your future self will thank you for the careful planning.
If you’ve already inherited or planted problematic perennials, you have options: contain them with edging barriers, commit to aggressive management if you love them enough, or remove them for better alternatives. Either way, use landscape fabric, quality tools, and realistic expectations to create a garden that brings joy rather than frustration. The most successful gardens aren’t fancy or complicated–they’re filled with plants that naturally thrive in their location and require the level of care their gardener can realistically provide.
Frequently Asked Questions
Can I grow these problematic perennials if I don’t mind the maintenance?
Yes, but be honest about your commitment level. Plants like butterfly bush and bee balm can work if you genuinely enjoy frequent deadheading and pruning. The issue arises when gardeners expect low-maintenance plants but choose high-maintenance varieties. Know yourself and your available time before planting.
Are there good alternatives to these problematic perennials?
Absolutely. For mint lovers, try growing culinary herbs in containers instead. Replace butterfly bush with native shrubs or repeat bloomers that require less deadheading. Substitute daylilies with coneflowers or salvia, which are less aggressive and equally attractive to pollinators.
What if I’ve already planted one of these problem perennials?
Install barriers around it immediately with edging or landscape fabric. If it’s spreading uncontrollably, remove it entirely using a digging fork to extract all rhizomes and roots. Complete removal often requires multiple seasons of vigilant maintenance to catch new sprouts.
Do problem plants perform differently in different climates?
Yes, significantly. Butterfly bush is invasive in warm climates but more manageable in cold regions. Research your specific USDA zone and local gardening conditions, as what’s problematic in one area might behave better in yours. Check regional invasiveness lists before planting.
How do I know if a perennial will spread aggressively before I plant it?
Read detailed plant descriptions that specify spreading method (runners, rhizomes, self-seeding). Check your local cooperative extension office for invasiveness information. Ask experienced local gardeners what works in your area. Garden tags that specify ‘clumping’ growth habit are safer than those mentioning spreading characteristics.
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