Lobelia siphilitica, generally called blue cardinal flower or great blue lobelia, is an easy-to-grow perennial for U.S. Department of Agriculture plant-hardiness zones 3 to 10. Lobelia types a clump of medium to dark-green leaves which are formed or oval. On stalks that grow 2 to 3-feet tall, bright-blue flowers bloom in summer. Lobelia thrives in moist to damp areas, making it a stylish addition along streams and ponds or in water gardens and bogs.

Clear grass and weeds from a website in full sunlight. Full sunlight is preferred by Lobelia, but does well in shade when the soil might be dried out by the warmth.

Test and amend the soil. Lobelia wants moist, fertile soil having a pH of 6.1 to 7.5. Add any soil amendments and well-rotted compost or manure 8 weeks before planting.

Dig a hole that’s slightly larger in relation to the nursery container. Invert the container and slide the plant out. Use a hand cultivator or your fingers to loosen the roots. Place the lobelia in the hole and fill the hole with all the garden soil. Water gently to to be in the soil round the roots.

Keep the soil moist; don’t allow it dry between watering. As it may cause diseases avoid wetting the foliage.

Lobelia after it exhibits signs of development. A high- potash plant foods every two months throughout the growing period.

Pinch the stems back by half in case a plant is preferred. Deadhead, or off, faded blossoms to promote re- .

Watch for signs of leaf place, or rust, smut and snails or slugs. Toss them away and remove diseased plants or plant parts; don’t compost them. Hand sprinkle diatomaceous earth round the roots of the lobelia or select slugs and snails.

Add a 1- to 2 inch layer of mulch in the fall. Don’t reduce lobelia again. Water lightly through the winter; the crops can be killed by extreme watering.

Propagate lobelia by dividing and lifting the plant every 2-3 years. In ideal conditions that are growing, it self-seeds easily, but isn’t considered invasive. In reality, it’s recommended instead of pond margin crops from the California Invasive Plant Council.

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