Lobelia care guide
Lobelia erinus
Also known as: Edging lobelia, Trailing lobelia
Pets and children
Considered toxic
Lobelia species contain lobeline, and in dogs and cats eating it has been linked to vomiting, diarrhea, weakness and heart rhythm problems; keep it out of reach and consult a veterinarian (or a doctor, for a child) if eaten.
How often to water Lobelia
- Spring–Summer (Mar–Sep)
- Every 3 days
- In spring water thoroughly once the topsoil dries, as a guide; in midsummer heat keep it in partial shade and on the dry side.
- Autumn (Oct–Nov)
- Every 3 days
- Fall-planted seedlings are growing, so about every two or three days once the surface dries is the guide.
- Winter (Dec–Feb)
- Every 7 days
- Growth slows in winter; as a guide, water in the morning two or three days after the topsoil dries.
Light and placement for Lobelia
A sunny spot is the guide, but it dislikes heat and humidity, so from the rainy season through summer an airy, bright, partly shaded place helps it survive.
Overwintering Lobelia
Overwintering guide: 0°C (32°F) or above
Fall-planted seedlings are fairly cold-tolerant and generally overwinter outdoors out of frost, such as under the eaves; on hard freezes, a fleece cover is usually enough.
Fertilizing and repotting Lobelia
Fertilizer
Mix in slow-release fertilizer at planting and give liquid feed about every two weeks in bloom, with none while the plant struggles in midsummer.
When to repot
Spring–Summer (Mar–Sep), Autumn (Oct–Nov)
Common problems with Lobelia
- Rainy-season humidity and midsummer heat make the plant collapse and die.
- Overwatering rots the roots and the whole plant yellows.
- Left alone after flowering, the plant weakens.
Tips for growing Lobelia
- Cutting back by about half after the first flush can bring a second bloom in fall.
- To carry it through summer, keep it in cool partial shade out of the rain.
- Planting seedlings in fall grows a bigger plant that mounds with flowers in spring.
These are AI-generated general guidelines. They vary with the variety, the placement and the pot size. For effects on pets or children, consult a veterinarian or a doctor.
Keep your plant log going
Greenery is a free app that keeps your plant care going, with watering reminders and photo records. Available on iOS and Android.
