If you dream of a vibrant, low-maintenance landscape that returns beautifully year after year, you probably prefer a mix of many perennials. While these attractive, popular plants promise effortless charm, they often come with hidden headaches, from attracting pests and diseases to demanding specific conditions for growth.
To avoid making mistakes in your garden, we talked to a plant expert to identify seven common perennials that are far more trouble than they’re worth. Before you head to the nursery, read on to find out what problem leaves to leave this season, the specific maintenance nightmares they cause, and alternative plants that will look great without all the effort.
1. Alpine delphinium (Dolphins breed)
The magical alpine delphinium is the highest A favorite perennial plant of gardenerssays Marina Prokaten, plant expert Plant Identification and Care Application Plantum. These tall-stemmed plants are covered in elegant bell-shaped flowers that come in a range of colors, including blue, pink, white, purple or cream. However, they are unreliable and sharp, and therefore difficult to care for in any garden. “They require frequent support to stay upright; are often affected by powdery mildew and slugs; and decline in hot, humid summer weather,” explains Proketen. Delphiniums also need full sun and soil that drains very well.
Increase this instead: Suspicious Knight’s-Spur (Integrate the jet)
2. Peony (Paeonia officinalis)
Peonies are attractive plants, boasting gorgeous pink or red flowers that usually appear in late spring, Procaten says. “Peonies aren’t that difficult to grow, but they do require maintenance,” she explains. “Their big, heavy blooms break after rain, so they usually need a strong support cage.” This is in between High maintenance plantsFlowering requires full sun but balanced with afternoon shade, well-draining soil, consistent moisture without waterlogging, and ample room to grow.
Peonies are susceptible to diseases such as botrytis and phytophthora blight, and some sap-sucking insects can damage the plant. “They also have a relatively short flowering period,” says Procaten. They need a period of cold dormancy to thrive. Finally, peonies are very difficult to transplant once they are established.
Increase this instead: French rose (Gaelic rose)
3. Red azalea (Symmetrical Rhododendron)
Azaleas are beautiful flowering shrubs known for their leathery green leaves and shiny, ruffled flowers in vibrant shades of pink, white and crimson. Unfortunately, they’re notoriously unforgiving, even for the average plant lover, Procaten says. “They need highly acidic soil, pure rainwater, and because of their shallow root system, they die quickly if the soil gets too dry or waterlogged,” she says. Also, their delicate buds are easily damaged by harsh winter drafts and intense afternoon sun. Red azaleas are native to East Asia and are more tender in the West, so be careful when planting A selection of plants like this for your garden.
Increase this instead: Bigleaf Hydrangea (Hydrangea macrophylla)
4. Bearded Iris (German rainbow)
Bearded irises are admired for their unique sword-like leaves and multi-layered petals in a rainbow of colors with soft, fuzzy centers. However, achieving that picture-perfect bloom requires some precision, warns Procaten. “Their thick roots should sit just above the ground to get enough light, as burying them even slightly will stop the plant from blooming and rotting,” explains Procaten. “They are also susceptible to bacterial and fungal diseases during rainy weather and need to be dug up and divided every few years.” Finally, overcrowding is another common problem as these plants mature.
Increase this instead: orange daylily (Hemerocallis yellow)
5. Tall Garden Phlox (Phlox paniculata)
This classic flower adds a lot of color to gardens that have started to lose it as other perennials shed their flowers, says Procaten. They are known to bring color and fragrance to garden borders, available in red, white, blue, pink and crimson. This species also attracts pollinators such as butterflies and hummingbirds to the yard. However, they are difficult to grow due to susceptibility to mildew and rot diseases.
Increase this instead: Candy Cloud Blue Mounding Flock (Phlox hybrida)
6. Dahlia (Dahlia x hybrida)
Dahlias come in a rainbow of vivid colors and variegated blooms that can look like delicate peonies to perfectly round pompoms, Procaten says. However, they are high maintenance, as they are sensitive to both extreme heat and cold temperatures. “Hybrid dahlias in particular are very labor intensive; they can’t last Cold winters mean you have to dig up, disinfect, and carefully store their tubers every fall,” explains Procaten.
Increase this instead: Purple coneflower (Echinacea purpurea)
7. Gardenia (Gardenia jasminoides)
Gardenias are a stunning garden favorite, beloved for their bright white flowers and incredible, sweet fragrance, Procaten says. “However, these tropical plants are quite fussy and can drop their buds overnight due to cold drafts or lack of light,” she explains. “They also need a clear difference between day and night temperatures, and are extremely vulnerable to insects like spider mites.” You may also see their leaves turning yellow, which can be addressed by fertilizing with iron.
Increase this instead: Mock Orange (Philadelphus coronarius)
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