Starship Blue Cardinal Flower

Light Needs

Partial Sun to Full Sun

(At Least 5 Hours of Direct Sunlight)

Mature Height

28-32 Inches

Mature Spread

18-20 Inches

Growing Zones

6 to 10

One of the few true blue perennials, Starship Blue Cardinal Flower Lobelia is an outstanding example of an improved cultivar. While most L. speciosa hybrids tend to be short lived, this cultivar of L. speciosa is a knock out with its violet blue 1 to 2 inch flowers on tall spikes and its rosette of basal leaves in a bright green. Tending to prefer a very moist to wet habitat, lobelia can be grown in your drier soil with a little care and maintenance from you. It is worth the extra effort! Starship Blue Cardinal Flower Lobelia is one of the earliest flowering lobelia in spring.

Native to North American where it is found in wetlands, along streams and in dense damp woodlands, Lobelia speciosa has intrigued gardeners for centuries. Starship Blue grows reliably in Zones 6-10, preferring the hot humid summers over the cool woodland climates, so it adapts fairly well into a not-so-wet garden environment. Now you have two options for enjoying these lovely perennials, a bog garden, wetland or pond edge garden setting, or a well-drained soil garden where it can be kept consistently moist. This tough perennial can even survive brief floodings, so don’t be afraid to plant it streamside or in a wetland area.

Starship Blue Cardinal Flower Care

Plant in full sun in Northern cooler climates and when in moist to wet conditions, and by rule of thumb, opt for part shade in hot humid Southern gardens. If planting in drier well draining soil, keep it consistently moist with drip irrigation and an application of mulch to hold moisture in, plus keep it in the shade to reduce evaporation of the water in the soil. True of most North American wildflowers, fertilizer is not typically needed. Lobelia tolerates a wide range of soil types from poor to fertile, and also adapts to a wide range of soil pH from acidic to alkaline. This is truly a versatile perennial for warm winter gardeners. This lobelia loves the heat.

Deadheading is not needed to keep lobelia flowering for you, but it does help clean up spent flowers and may trigger a rebloom at a later time. Resist cleaning the foliage up in late fall and winter to allow it to protect the roots in colder winter regions. Mulch the root zone in cold winter zones, and clean everything up in early spring before new growth emerges.

Starship Blue Cardinal Flower Spacing

Space your lobelia 18 to 20 inches apart from other plants to allow it room to grow. Cardinal flowers grow to about 32 inches tall and 20 inches wide so need some room to spread out. Pair this beautiful blue flower with a large hosta, whose flower spikes will rival the lobelia for height and whose base needs are very similar to lobelia, making maintenance a lot easier. All in all, gardeners will agree that Starship Blue Cardinal Lobelia is worth every ounce of care that they expend for it once they see it in their spring gardens.