Great Blue Lobelia

Botanical Name

:

Lobelia siphilitica

Plant Type

:

Herbaceous perennial

Seasons

:

Plant in spring; blooms in mid to late summer

Sun Level

:

Full sun (at least 6 hous daily), part shade, or shade; appreciates some shade from the hot afternoon sun

Ideal Soil Temperature for Planting

:

Keep very warm, around 70°F (21°C)

Soil Type

:

Chalk, clay, loam, or sand; adaptable to common garden soils or clay with average moisture; excellent for damp clay soils

Hardiness Zones

:

4–9 (USDA)

Germination

:

1–3 weeks

P.H. Level

:

6.5–7.5 (slightly acidic to neutral)

Water/Irrigation

:

High water needs; prefers moist to wet locations; keep soil moist; not drought-tolerant

Fertilization

:

Add plenty of peat moss when planting

Habit

:

Clump-forming, upright

Propagation

:

Seeds, division

Final Plant Height

:

2–3 ft

Spread

:

1–2 ft

Flowers

:

Deep blue flowers in spikes

Attracts

:

Butterflies, hummingbirds, and birds; special value to native and bumble bees

Uses

:

Perennial border, wild garden, native plant garden, woodland garden, naturalized planting, along ponds or streams; great as a cut flower

Companions

:

Asclepias incarnata ‘Ice Ballet’, Anemone canadensis, Carex comosa, Chelone glabra, Eupatorium coelestinum or Osmunda cinnamomea

Pruning

:

Remove any yellow or damaged leaves during the growing season to keep the plant healthy and strong

Toxicity

:

Poisonous if eaten in large quantities

Pests

:

Weevils, leaf beetles, leafhoppers, aphids and thrips

Diseases

:

Root rot, leaf spots, gray mold

Confused With

:

Cardinal Flower (Lobelia cardinalis)