Lobelia is a tender perennial widely grown as an annual plant in most USDA zones. This colorful plant belongs to the Campanulaceae (or “bellflower”) family.
Most varieties of this lobelia have a trailing growth habit and come in many colors. It is commonly sold in the annuals section of the garden center and has a wide variety of uses.
This type of lobelia is perennial only in zones 10 and 11. For this reason, in the North, it is treated as an annual and functions in the ways that another popular bedding plant functions: sweet alyssum. But lobelia comes in more colors than sweet alyssum and is more versatile due to the fact that it performs better across a spectrum of sunlight conditions ranging from full sun to partial shade.
Lobelia does not require a lot of maintenance. It does not need to be deadheaded because the plant self-cleans. Nor do deer tend to eat it. Lobelia does, however, tend to decline if subjected to full sun during very hot summers. If this happens to your plant, you can revive it by cutting it back and then providing water on a regular basis.
One of the selling points of lobelia is that it is not fussy about sunlight levels, flowering nicely in anything from full sun to partial shade. In the South, it is best to grow it in partial shade. In the North, grow it in full sun (as long as you water it regularly) to enjoy maximum flowering.
Lobelia likes rich, well-drained soil.
Keep the soil of lobelia evenly moist.
You can fertilize lobelia with compost, but, since it is a heavy feeder, many gardeners prefer to feed it with a liquid fertilizer every two weeks.
Uses for Lobelia
Its trailing growth habit, dense flowering, and tolerance for either sun or shade make “annual” lobelia a highly versatile plant. Here are just a few of the many uses for it during the summertime in a Northern landscape:
- As a flowering ground cover
- In rock gardens
- Use lobelia with blue flowers, along with red salvia and white petunias, in patriotic landscaping displays (July 4th plantings and plantings around cemetery monuments on Memorial Day).
- Use a lobelia with white flowers in a moon garden.
- Grow your lobelia in a hanging basket and display it on a porch.
- Install several lobelia plants along the edge of a mixed container garden, such as a whiskey barrel, and display it on your patio. The trailing growth habit of the lobelia allows it to cascade down the sides attractively.
- Likewise, as an element in mixed window boxes, lobelia can be the plant that hangs down the side of the window box, while taller plants such as Victoria blue salvia provide the backdrop.
- Use lobelia as an edging plant along a walkway.
- Plant lobelia in your butterfly garden as a short plant to complement taller species such as common milkweed.
Information courtesy of TheSpruce.com