Lobelia Growing Guide
Lobelia erinus
Crop Rotation Group
Miscellaneous ●
Soil
Fertile, well-drained soil, or use containers.
Position
Full sun to partial shade.
Frost tolerant
Limited. Lobelia can take cool weather but is easily damaged by frost.
Feeding
Mix a standard application of a balanced organic fertilizer into the soil prior to planting. In midsummer, drench plants with a liquid plant food to stimulate new growth.
Companions
Lobelia varieties that bloom blue are wonderful cascading flowers to combine with petunias or other easy annuals in containers. You also can use lobelia to edge beds because of its small size.
Spacing
Single Plants: 5" (15cm) each way (minimum)
Rows: 5" (15cm) with 5" (15cm) row gap (minimum)
Sow and Plant
Sow tiny lobelia seeds indoors, on top of moist seed starting mix, and provide very bright light. Most gardeners buy lobelia seedlings, which are widely available as bedding plants in spring.
Our Garden Planner can produce a personalized calendar of when to sow, plant and harvest for your area.
Notes
Lobelia is a great cool-season flower for adding vivid blue to the garden. Some varieties bloom white or pink.
Harvesting
In early summer, pinch back plants to stimulate the growth of new blossom-bearing branches.
Troubleshooting
High heat can cause lobelia to suffer, but the plants stay in bloom for many weeks in climates with cool nights.
Planting and Harvesting Calendar
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Pests which Affect Lobelia