Lobelia laxiflora is an interesting sub-shrubby, rhizomatous perennial member of the genus Lobelia from Mexico and Central America. It is hard to believe it is related to the cute little blue annual Lobelia erinus that is grown as an edging plant. The genus Lobelia belongs to the Campanulaceae family and contains a diversity of species.
Lobelia laxiflora grows to about 1.5-2m in my garden and flowers in late winter through to the end of spring. A marginally frost hardy plant, it has long, narrow, finely toothed leaves which form a lush green mound, smothered in hanging tubular orangey-red and yellow flowers. It can be a bit floppy, so benefits from support from cradle stakes. It is an effective addition to the hot-coloured shrub scene at this time of year, if grown with plants such as Streptosolen jamesonii and Salvia gesneriiflora 'Tequila'.
This plant likes sun and can cope with dryish soil. It is quite a feature in various beds in the Royal Botanic Gardens in Sydney, and I bought my original plant from the Friends' Nursery there. I cut it back fairly hard at the end of flowering, around the end of November. Note that it does sucker from the base, forming a clump, but I have not yet found it invasive. I do find it self-seeds a little bit, so I dig up these plants to give away and find this seems the best method of propagation as cuttings seem reluctant to strike. Detaching rooted suckers from the edge of the plant is another method of propagation.
Note: I believe that the plant I grow (as pictured and described above) is actually Lobelia laxiflora subsp. angustifolia but I have yet to verify this.
Postscript: Eventually I tired of this plant as it did spread beyond its allotted space, and I found it fairly ungainly in its form. It did also self-seed quite a bit more than I expected. Perhaps in a garden with more space, it would perform better.