Flower Spikes That Pack a Visual Punch in Summer Gardens

Is your perennial garden lacking structure? Consider the spike. Not the most romantic name, but it delivers a visual punch. Spikes exist for every season, but spiky flowers seem particularly present in early summer. Here are favorites.

Baptisia (False Indigo)

Near the top of my must-have list is baptisia (Baptisia australis and cultivars, zones 3–9). Sometimes called 'false indigo' because Native Americans used it for blue dye. Blue spires point skyward in early summer. It thrives in average to poor soil, full sun to part shade. As a pea family member, it fixes nitrogen; its taproot means plant it permanently. New colors like 'Twilite Prairieblues' (purple with yellow base, steely blue foliage) are exciting. At 3–4 feet high and wide, baptisias serve as shrub stand-ins in lean sites.

Gas Plant

Another favorite I haven't planted yet: gas plant (Dictamnus albus, zones 3–8), named for oil that supposedly sparks if ignited. Pink to white flowers in early summer; like baptisia, hates being moved. An investment plant—rarely looks great in pots, takes a year or two to establish, but pays off. Full sun to light shade, average soil. Grows 3 feet tall and wide, moderate drought tolerance once settled. Handle carefully—oils in leaves and flowers can irritate skin.

Mulleins (Verbascum)

Mulleins (Verbascum species and cultivars, zones 5–8) are many, but 'Southern Charm' is a great garden plant. Unlike biennial kin, it returns yearly. Daintily sized with peachy pink flowers and darker purple centers. Happy in full sun, lean well-drained soil, ~3 feet tall, 2 feet wide. Deadhead for repeat bloom.

Acanthus (Bear's Breeches)

Acanthus (Acanthus species, zones 5–10) is a shrub-size plant with amazing early to midsummer flowers and big, beefy foliage. Acanthus spinosus may be hardy to zone 5; A. mollis (pictured) better in zones 7 (maybe 6b) and south. Full sun to part shade, average to lean soil—careful in loose soils where it may spread by runners. Most grow 3–4 feet wide, up to 5 feet in bloom.

'Walker's Low' Catmint

For a casual spike, 'Walker's Low' catmint (Nepeta x faassenii 'Walker's Low', zones 4–8) is a favorite. Sweetly scented foliage, clear lavender flowers, thrives in lean soil and sun. Grows ~3 feet high and wide—give it space to spread, as it may shade out less competitive plants.

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