9 named cultivars

perennial

Hybrid Lobelia

The Story

Plant Bio

Lobelia speciosa is a group of garden hybrids raised from L. cardinalis, L. fulgens and L. siphilitica, grown as an upright perennial two to three feet high. Spires of lavender, pink or red flowers open from July to September above green foliage that is often flushed red, purple or bronze. The whole plant is stiffly vertical and narrow.

These hybrids are frequently short-lived, and gardeners lose them over winter rather than in the growing season, usually to wet or freezing soil around the crown. Lift and divide every second spring to keep young growth coming, and in the coldest gardens treat them as you would a tender perennial.

Uses & Benefits:

Vertical spires in lavender, pink or red over bronze-flushed foliage through late summer.

One of the few showy perennials that thrives in ground too wet for a conventional border.

Tubular flowers are worked by hummingbirds and long-tongued bees at a thin point in the season.

Essentials

At a Glance

Plant Type

Perennial

Height

28 inches

Width

21 inches

Light

Full Sun, Partial Sun

Zones

5, 6, 7, 8, 9

Water

High

Humidity

High

Lifespan

Perennial

Native To

Garden origin; parent species from North America

Toxicity

Toxic if ingested

Planting

How to Grow

Plant in spring in rich soil that stays moist to wet.
Choose full sun in the north, part afternoon shade further south.
Keep the soil damp; it will not tolerate drying out.
Feed with a balanced fertiliser as growth begins.
Deadhead spent spires to prolong the display.
Divide every second spring to keep the clump vigorous.

Pro Tip

Winter wet at the crown kills more of these than cold does; sharp drainage in winter matters as much as moisture in summer.

Keep It Thriving

Care Guide

Do

Keep the soil consistently moist to wet 💧
Divide every second spring to renew the clump 🌱
Deadhead spent flower spires 🌸
Mulch the crown in cold gardens 🍂

Don't

Let the soil dry out at any point in summer ❌
Leave the crown sitting in winter wet ❌
Assume it will be long-lived without division ❌

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Divide
Water

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Pond and stream margin plantingMoist woodland or shade garden edgeWet meadow and bog garden

Companion Plants

AstilbeJoe Pye Weed Siberian Iris LigulariaSwamp Milkweed

Multiply

Propagation Methods

Good to Know

Common Questions

Hybrid Lobelia questions

What zones can Hybrid Lobelia grow in?

Hybrid Lobelia is hardy in USDA Zones 5–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Hybrid Lobelia deer resistant?

Yes — Hybrid Lobelia is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Hybrid Lobelia bloom?

Hybrid Lobelia typically blooms in midsummer to early fall through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Hybrid Lobelia need full sun?

Hybrid Lobelia does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.