Lobelia (primarily Lobelia erinus and its hybrids) is a charming, low-growing annual prized for its profuse, delicate flowers in shades of intense blue, purple, pink, white, or bicolor.

**Lobelia** (primarily *Lobelia erinus* and its hybrids) is a charming, low-growing annual prized for its profuse, delicate flowers in shades of intense blue, purple, pink, white, or bicolor. The trailing varieties are especially popular as “spillers” in containers, pairing beautifully with your previous plants like Sweet Potato Vine (trailing), Juncus (upright), and Lantana (mounding). ### Growing Conditions in Fort Collins Fort Collins’ cool nights and intense summer sun create a mixed bag for Lobelia — it loves the cooler spring/fall but can struggle in peak summer heat. - **Hardiness**: Tender perennial in Zones 9–11. In Zone 5b, treat it strictly as a **summer annual**. It won’t survive winter outdoors. - **Planting time**: Mid-to-late May, after the last frost and when nights are reliably above 45–50°F. It prefers cooler weather for establishment. - **Sun**: Full sun to partial shade. In Colorado’s hot afternoons, afternoon shade or eastern exposure is ideal to prevent scorching and keep blooms coming longer. Morning sun is best. - **Soil**: Rich, well-draining, slightly acidic to neutral soil. Excellent in containers with quality potting mix. - **Water**: Keep soil **evenly moist** but not soggy. Consistent moisture is key — it wilts quickly if it dries out, especially in dry Colorado air. Water regularly, especially in containers. ### Care Tips - **Growth habit**: Trailing (cascading 6–12+ inches) or compact mounding types. Perfect for hanging baskets, window boxes, and mixed pots. - **Bloom time**: Best in spring and early fall. It may slow or stop blooming in midsummer heat but often rebounds in late summer/fall if cut back. - **Maintenance**: Trim back by about 1/3 to 1/2 if it gets leggy or stops blooming — this encourages fresh growth and a second flush. Self-cleaning (no deadheading needed). - **Fertilizer**: Use a balanced liquid fertilizer every 2–4 weeks during the growing season. - **Pests**: Generally low-maintenance and deer-resistant, but watch for aphids or slugs in moist conditions. Lobelia adds a beautiful cool-toned contrast (especially the blues) to warmer-colored plants like Lantana and the chartreuse/purple of Sweet Potato Vine. Great for pollinators too! If you have a specific variety (e.g., trailing ‘Regatta’, ‘Fountain’, or heat-tolerant types) or a photo, I can refine the advice further.