Lobelia valida grows easily in the garden given a sunny position with light well- drained soil, enriched with compost. It is ideal for coastal gardens. Flowering abundantly throughout summer it is best to replace plants regularly, as the stems tend to get untidy and woody at the base after a year's vigorous growth. Plants live for about 3-4 years, but one might wish to replace them sooner in the garden. For the best display, the plants should be planted 15cm apart. Lobelia also looks beautiful mixed with other summer flowering perennials such as Pelargonium peltatum ( Ivy leaf pelargonium), Geranium incanum (carpet geranium) and Diascia integerrima.

Lobelia valida can be propagated by seed or cuttings. The plants set seed freely, producing small little black seeds. The seed can be sown any time of the year into seedtrays filled with a well-drained medium. Sow the seeds thinly as the germination is usually good and cover lightly with sifted soil or white sand. Place the trays in the shade and keep moist. Germination takes about a month, with the young seedlings grow very slowly in the beginning. Prick out the seedlings as soon as they are large enough to handle and grown on in bags until they are big and strong before planting out into the garden.

Strong tip cuttings are best taken in spring ans summer when they are less inclined to rot. The young plants respond well to fertilizer feeding and by pinching the tips, the plants are encouraged to grow bushier. Lobelia valida prefers a slightly alkaline soil.