Have you grown weary of Lobelias, whose lovely blooms reside above a rather untidy base? If so, you may be interested in Dan Heim’s brilliant solution to this age-old challenge—a small-statured L. cardinalis and L. syphilitic backcross, known as ‘Grape Knee-Hi’. Painted with vibrant deep purple hues, the long lasting and freely flowering, tightset spikes crown upright stalks and good-looking compact foliage that stands on its own all season long.

Blooms July–August

Size: 2' 0" high x 15" wide.

Hardy to zone 6.

We have Thurman Maness to thank for this lovely cultivar, another cross between Lobelia cardinalis and Lobelia siphilitica. A dense tower of dusky plum flowers creates a pleasing blend of muted purples when planted with Verbena hastata and Astrantia ‘Lars’.

Blooms August–early October.

Size: 2-1/2' – 3' 0" high x 18" wide.

Hardy to zone 4.

A lush-looking, bushy perennial capable of enduring considerable neglect, this impressive Lobelia plays host to festive bicolored blooms. Spreading by underground rhizomes, a close thicket of slender, yet sturdy, red-tinted stems strikingly set off narrow and lustrous, pointed green leaves that extend 2 to 4 in. Slim, 2 in. long red tubes are loosely clustered at shoot tips, while each bright-hued flower flares to reveal a sunny yellow throat.

Hailing from Arizona and Mexico, the Mexican Lobelia entices gardeners and hummingbirds alike with nectar-rich blossoms, can tolerate some shade, but looks its best in sunny, dry sites and has been reputed to possess anti-inflammatory alkaloids.

Blooms June–September.

Size: 2' 0" – 2-1/2' high x 2' 0" – 3' 0" wide.

Hardy to zone 8.

Dressed in a crisp snowy white, the profusely flowered tapers of this Lobelia stand in sharp relief to its dark green foliage. A newly selected form of our U.S. native, ‘White Candles’s small, compact stature keeps its lift all season, lending a clean and classic look, especially when partnered with Geranium ‘Orion’.

Blooms July–August.

Size: 18" – 20" high x 18" wide.

Hardy to zone 5.

Many gardeners say the 2-lipped deep purple flowers of this tall cultivar reign supreme among Lobelias, and we whole-heartedly agree! Long-blooming, velvet-rich, terminal racemes crest upright stalwart stalks lined in lanky, semievergreen lance-like green foliage that’s infused with violet hues and lush panache. A mighty-fine addition to moist mixed borders, cottage gardens and pond peripheries, clump-forming ′Hadspen Purple′ can be planted in bold swaths amidst Phlox paniculata ‘Gzhel’ and Nepeta ‘Hill Grounds’, where it promotes vibrantly hued accents plus bee and butterfly enticements. (PBR)

Blooms July–September

Size: 2-1/2' – 3' 0" high x 18" wide.

Zone 6b.

The lush tropical color scheme of this somewhat tender Chilean native is alluring. Cloaked in broad and pointed, felted pale green foliage, each soaring purple-tinged stem is crowned with a large, tapering raceme of warm brick-red blossoms. From the swollen base of each flower, a claw-like lower lip curls under and a tuft of gray stamens extends upward. A perennial of nearly monumental stature that likes it hot and on the dry side, Lobelia tupa can be associated with Melianthus, Muhlenbergia and Morina longifolia for a dynamic mélange of color and shape in the border.

Blooms July–October

Size: 6' 0" – 8' 0" high x 3' 0" – 4' 0" wide.

Hardy to zone 8.