14 Underrated Plants That Will Add an Element of Surprise to Your Garden

Golden Valerian

Sam Keitch, manager of design and procurement for the Pennsylvania Horticultural Society, recommends Patrinia scabiosifolia for its "late-season display."

"With many of our darker-toned grass plantings, Patrinia has behaved perfectly, almost without being noticed amongst the grass until it bolts," he says. "The loosely-held flowers are a rich yellow and persist into the fall. It will reseed, but for me, that is a desirable attribute. It also serves as a great cut flower."

• Zone: 5 to 8
• Size: 36 to 60 inches tall by 18 to 24 inches wide
• Growing conditions: Full sun; rich, well-drained soil
  

Gladiolus "Boone"

This "reliably hardy" gladiolus variety is another of Keitch's favorite flowers. "It is wonderful for the front of a border, with soft peach tones that go with everything," he says. "While it is not the longest bloom period, its elegance more than compensates. It has become the perfect companion for Agastache 'Blue Boa.'"

• Zone: 6 to 9
• Size: 24 to 48 inches tall by 12 inches wide
• Growing conditions: Full sun; well-drained soil
  

Arisaema sikokianum

Plant this striking variety of Jack-in-the-pulpit alongside Epidmedium and Brunnera plants, says Keitch. "There are many great hardy Jack-in-the-pulpit species to add a unique feel to a shade garden, but this Japanese species has dark purple spathe, which is nearly black in appearance," says Keitch. "The deeply cut leaves may have a marbling effect, and between them emerges a single flower with an exposed white spadix. This contrasts perfectly with the dark 'pulpit.'"

• Zone: 5 to 8
• Size: 12 to 20 inches tall by 12 to 18 inches wide
• Growing conditions: Full to partial shade; moist, well-drained soil
  

Sanguisorba 'Blackthorne'

Cylindrical Sanguisorba grows in a variety of colors; Keitch prefers the Blackthorne version. "The compound foliage is handsome, and the deep rose flowers are held upwards of five feet in the air," he says. "After several years, the vertical habit of the flowers will rival anything else in the late summer border. This may be my favorite tall perennial, which is a dangerous claim, but each year, I find a deeper appreciation for this burnet."

• Zone: 4 to 8
• Size: 60 to 72 inches tall by 24 to 36 inches wide
• Growing conditions: Full sun; moist soil

Sorghastrum nutans 'Golden Sunset'

This native grass grows up to 72 inches tall, says Keitch—so it works well as both a border and backdrop—and boasts "massive, 9-inch golden flowers."

"Other cultivars have silver foliage, but this selection has olive green foliage that is held below sight lines, allowing for complimentary perennials to be knit through mass plantings," says Keitch.

• Zone: 3 to 9
• Size: 48 to 72 inches tall by 24 to 36 inches wide
• Growing conditions: Full sun; rich soil

Tetrapanax 'Steroidal Giant'

This eye-catching plant may be hard to track down, says Keitch, but many gardeners will willingly share a runner (if you can find a grower). "Known as the giant rice paper plant, this coarsely lobed foliage creates a dramatic statement piece," says Keitch. "The large leaves have a tropical aesthetic, but in the northeast, it dies back to the ground. This is a bold statement for someone who is an avid gardener."

• Zone: 7 to 10
• Size: Up to 15 feet tall by 15 feet wide
• Growing conditions: Part sun; adaptable to moisture
  

Canna x ehemanii

The Canna x ehemanii hybrid dates back to 1843 and was a popular choice for Victorian gardens, says Kenneth Silveira, plant specialist at the United States Botanic Garden. "This Canna is quite rare and used to be almost impossible to find but seems to be coming back into favor," he says. "It stands out from its cousins in the fact that the flowers are pendulous with fuchsia bells that dangle over your head."

• Zone: 8 to 11
• Size: 6 to 9 feet tall by 3 to 4 feet wide
• Growing conditions: Full sun to partial shade; rich, organic soil
  

Kalanchoe prolifera

"If you want an exotic plant that looks like it came out of the Jurassic era, look no further than this Kalanchoe," says Silveira. "It is a very fast grower and has huge, succulent, lush green leaves. It is very drought tolerant, but the more you water it, the faster it will grow, and the larger this beast will get."

• Zone: 9 to 11
• Size: 6 to 9 feet tall by 3 feet wide
• Growing conditions: Full sun; well-drained soil

Kniphofia 'Lola'

While this variety of red hot poker shows off the plant's well-known yellow blooms and red buds, the showstopping size makes it a dynamic garden addition, says Silveira. "The foliage is grass-like and can be evergreen but dies back in a harsh winter," he says.

• Zone: 6 to 10
• Size: 6 to 7 feet tall x 4 to 5 feet wide
• Growing conditions: Full sun; well-drained soil
  

Colocasia 'Pink China'

Vibrant pink stems support the oversized, elephant-ear-shaped leaves on this hybrid. "This is another plant where the more you water and fertilize it, the bigger it will get," says Silveira. Though it prefers part shade, Silveira has successfully grown the plant in full sun—with frequent watering.

• Zone: 7 to 11
• Size: Up to 6 feet tall by 6 feet wide
• Growing conditions: Part shade; rich soil
  

Hedychium coronarium

While this plant may not look too interesting in the early part of the year, it "has a nice surprise come late summer," says Silveira. "It resembles a tropical corn plant most of the season, but in mid-August to fall, it bears green cones at the apex that burst forth with large, white, and extremely fragrant blossoms. The scent is reminiscent of gardenia."

• Zone: 7 to 10
• Size: 5 to 7 feet tall by 2 to 3 feet wide
• Growing conditions: Full sun to full shade; rich, well-drained or clay soil
  

Alpinia zerumbet 'Variegata'

This member of the ginger family, native to tropical eastern woodlands in Asia, boasts upright spreading clumps that can reach widths of 6 feet, says Tim Pollak, assistant manager and outdoor floriculturist at the Chicago Botanic Garden. "The cultivar 'Variegata' is a smaller more compact plant featuring striking bold creamy-gold striped foliage. Alpinia can be grown in large containers for a tropical effect, or they can be planted in the ground as a specimen plant."

• Zone: 8 to 10
• Size: 36 inches tall by 48 inches wide
• Growing conditions: Full sun to partial shade; rich, moist soil
  

Persian Shield

The iridescent leaves of Strobilanthes dyerianus make it an unexpected accent to any garden, says Pollak. "Native to Burma, this evergreen sub-shrub in the acanthus family has been grown since the Victorian times for its ornamental foliage, both indoors and out," he says. "They prefer warm, hot, and humid conditions to form a large, bushy, mounded plant."

• Zone: 10
• Size: 36 inches tall by 24 inches wide
• Growing conditions: Full sun to partial shade; evenly moist soil
  

Salvia guaranitica 'Black & Bloom'

Choose this plant for its dramatic blooms, says Pollak, which are deer-resistant and pollinator-friendly. "The large blossoms of this vigorous, upright grower have a significant presence in the garden border," he says. "'Black and Bloom' produces deep blue flowers carried high on ebony stems and blooms continuously throughout the summer."

• Zone: 8 to 10
• Size: 36 to 48 inches tall x 36 to 48 inches wide
• Growing conditions: Full sun; moist, well-drained soil