Lobelia Seeds – Lobelia erinus
Lobelia erinus • Campanulaceae • Native to South Africa (Cape Province)
Lobelia Seeds grow into trailing or compact plants with vibrant blue, purple, or white blooms. Ideal for hanging baskets, containers, garden borders, and colorful summer displays.
Seed Variety: White Lobelia Seeds
Quantity: 100 Seeds
Selected: White Lobelia Seeds / 100 Seeds
Germination depends on soil, temperature, moisture, and care. See our return policy for details.
At a glance
Lobelia erinus is toxic to people, cats, and dogs if ingested, so plant it where children and pets are unlikely to chew on it.
Botanical profile
Meet the Lobelia – Lobelia erinus
Step-by-step planting
Growing lobelia from seed takes patience at the start, but the process is straightforward once you understand what the seed needs to sprout and settle in.
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1
Start Seeds Indoors Early
Sow Lobelia erinus seeds indoors 10 to 12 weeks before your last expected frost, pressing the tiny seeds onto the surface of a fine-textured, moist seed-starting mix without covering them.
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2
Provide Light for Germination
Lobelia seeds require light to germinate, so place the tray directly under grow lights or in a bright south-facing window and keep the lights on for 14 to 16 hours a day.
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3
Maintain Warmth and Moisture
Soil temperature between 70 and 75 degrees Fahrenheit speeds lobelia seed germination considerably, so use a heat mat and keep the surface evenly moist with a gentle mist rather than overhead watering that can dislodge the tiny seeds.
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4
Be Patient Through Germination
Sprouting typically takes anywhere from 14 to 21 days under good conditions, though cooler soil temperatures, inconsistent moisture, or lower light can stretch that window, so resist the urge to give up too early.
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5
Thin and Pot Up Seedlings
Once seedlings show two sets of true leaves, thin clumps to avoid overcrowding or pot them up into small cells with a well-draining mix, handling them carefully because the stems are very delicate at this stage.
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6
Harden Off Before Transplanting
About a week before moving plants outside, set them in a sheltered spot outdoors for a few hours each day and gradually increase their exposure so they adjust to sun, wind, and fluctuating temperatures without shock.
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7
Plant Out and Situate Well
Transplant into the garden or containers after all frost risk has passed, spacing mounding types about 6 inches apart for use as a lobelia border plant or ground cover, and placing trailing lobelia at the edges of hanging baskets where the stems can cascade freely.
Year-round care
Spring
- Sow after last frost
- prepare soil with compost
Summer
- Water regularly
- feed monthly
Fall
- Harvest before frost
- store well
Winter
- Rest
- store seeds cool and dry
Full specifications
Shipping
- Orders are delivered within 8 to 16 business days.
- All orders include tracking.
- Free shipping on all orders.
- Seeds are packed in moisture-resistant, resealable foil packets.
Germination
Germination rates vary depending on climate, soil conditions, and care. Seeds perform best when planted in the right season at the correct temperature, with consistent moisture and adequate light. We take quality seriously and each batch is tested before packaging. If you have concerns about your seeds, reach out and we will do our best to help.
Frequently asked
Questions about Lobelia Seeds – Lobelia erinus
How long does Lobelia erinus take to germinate?
Under warm, well-lit conditions with consistent moisture, most lobelia seeds will sprout somewhere between 14 and 21 days. Cooler soil, low humidity, or insufficient light can delay sprouting by a week or more, so conditions matter as much as the seed itself. Tracking your soil temperature with a simple thermometer takes a lot of the guesswork out of the process.
Does lobelia need light to germinate?
Yes, Lobelia erinus is a light-dependent germinator, meaning the seeds need exposure to light to trigger sprouting. Press seeds onto the surface of your seed-starting mix and do not cover them with soil. Place the tray under grow lights or very close to a bright window, and germination rates tend to be noticeably better than when seeds are buried.
Can lobelia grow in full shade?
Lobelia erinus tolerates partial shade well and actually appreciates afternoon shade in hot climates, but full, dense shade leads to weak, leggy growth and noticeably fewer flowers. A spot with morning sun and dappled afternoon shade is often ideal in warm regions. In cooler northern climates, a full-sun position usually produces the most compact and floriferous plants.
Is Lobelia erinus toxic to cats and dogs?
Yes, all parts of Lobelia erinus contain alkaloids that are toxic to cats, dogs, and humans if consumed. Symptoms of ingestion in pets can include nausea, vomiting, weakness, and drooling. If you suspect a pet has eaten any part of the plant, contact your veterinarian or an animal poison control line promptly.
When should I start lobelia seeds indoors?
Count back 10 to 12 weeks from your average last frost date and use that as your indoor sowing target. Because lobelia seed germination is slow and seedlings grow at a modest pace, this long lead time ensures you have sturdy, bloom-ready transplants by the time outdoor conditions are right. Starting too late often results in plants that are still small and not yet flowering when it is time to set them out.
Why did my lobelia stop blooming in summer?
Lobelia erinus is known to slow down or even stop flowering during periods of intense heat, typically when daytime temperatures climb consistently above 85 to 90 degrees Fahrenheit. This summer slump is normal and not a sign the plant is dying. Shearing plants back by about one-third and giving them a light feed will usually trigger a flush of fresh growth and renewed flowering once temperatures cool in late summer or early fall.
Can lobelia be grown as a perennial?
Lobelia erinus is a tender perennial native to a mild climate, so in USDA zones 9 and above it can survive mild winters and behave as a short-lived perennial. In most of North America and northern Europe, however, it is grown as an annual lobelia flower because it cannot withstand frost. Gardeners in colder zones sometimes overwinter favourite plants in a frost-free greenhouse or bright indoor space, though starting fresh from annual lobelia seeds each season is generally the easier approach.