Mexican lobelia, Lobelia laxiflora, is not seen often in Sonoma county gardens; nonetheless, it is a good candidate for groomed borders as well as informal areas where it withstands some neglect and little water.
Many gardeners think purple when thinking of Lobelia, as in the tiny-flowered annual that’s excellent in hanging baskets, containers, or borders. Or the versatile Lobelia cardinalis may come to mind with its rich green foliage and striking dark red tubular flowers so attractive to hummingbirds. This cardinal flower likes some shade and loves water, plenty of it. In fact, it can be planted it in a pot and placed in a bog or water garden.
But their cousin, Lobelia laxiflora, which hails from Mexico and Central America, looks and behaves completely differently. It has a closer resemblance to Phygelius (cape fuchsia) or Epilobium (California fuchsia), both perennials with orange tubular flowers. But they are not even in the same families. Lobelia laxiflora is actually in the Campanulaceae family, and the other two are Scrophulariaceae and Onagraceae respectively, similar in looks, but not related.
With brilliant, two-lipped, tubular flowers, Lobelia laxiflora is a sun-loving perennial that needs only occasional water after becoming established. With excessive water, this lobelia spreads quickly and can become invasive. With less water, it stays in check, thrives, and blooms regardless. Clumps slowly spread into broad colonies that may be welcome to fill open space, but underground rhizomes must be removed to limit unwanted expansion.
Standing fairly straight, red-tinted stems up to three feet tall are clothed with narrow, linear leaves and bear bright 1½ in. long, orange-to-red blooms that beckon hummingbirds from June until frost before dying back. Growth renews the following spring.