Hardiness Zone: 8b
jhirsh from Hutto, TX
Generally speaking, lobelia prefers nutrient-rich, moist soil and grows (and blooms) best in climates where summer temperatures are cooler. You can start them from seed a week or two before your last frost date. Because your summers are hot, protect yours from afternoon sun by planting it in a sheltered spot where it will get partial shade. You may also want to mulch around young plants or add polymers to the soil to help it retain moisture. As plants grow, pinch them back to encourage bushy growth. If the heat starts to retard blooming, cut plants back by half and keep the soil moist. They will start to bloom again when cooler temps roll around. Lobelia tends to spread over the ground and works well in baskets and containers.
Lobelia seems easy to grow. It needs sun and plant it in the front of your beds, as it is so small. Usually I plant it as a border in most of my beds. It is pretty hardy and I have had a few even winter over under the mulch... when we have had mild winters in zone 5/6.
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