At a glance:
Latin Name: Lobelia hybrid 'Techno Heat'™ & 'Waterfall'™ series
Common Name: Lobelia
Flowers: Small, star-shaped; blue, light blue, or white
Foliage: Medium-green
Mature height: 10" with 12" spread.
Hardiness: Annual
Soil: Acid to slightly alkaline
Exposure: Full sun to light shade
Water usage: Medium
Sources: Local nurseries

Some plants are like Godiva chocolates: beautiful, tempting, irresistible, and not really all that good for you! That's the way I think of lobelia, those incredibly pure-blue flowering annuals that all nurseries start selling with the first warm days of spring. They are just too perfect. Yankee gardeners consider this a summer plant, but they don't know what "summer" is, at least not a Texas summer!

I am fascinated by these plants. I can't think of any other annual that cascades out of spring containers with such pure, sapphire-blue tones. Each spring when I see them on the nursery shelves, my fingers start to itch and somehow, the plants make it to the register and find their way home with me. I guess, like all gardeners, I'm always hopeful that by some chance, I can keep them alive to at least May.

Luckily, I actually get paid to find the best plants for Texas at the Dallas Arboretum. I was determined that there had to be a better lobelia out there, and went on a hunt. I wasn't too hopeful that I'd find one, but guess what? I not only found one variety, but two! These were more heat-tolerant than any others. Now pay attention ... I said "more" heat-tolerant, not "completely" heat-tolerant. At the Dallas Arboretum, we had them in flower and looking great through the middle of August.

The two varieties I found are the 'Techno Heat'™ series from Fischer and the 'Waterfall'™ series from Ball Flora. They grow like any other lobelia with soft, mounding foliage that cascades wonderfully over the edges of pots and continuously cover themselves in star-like flowers of blue, azure or white. The 'Techno Heat'™ series comes in three colors: 'White,' 'Upright Blue' and 'Light Blue.' 'Waterfall'™ series comes in 'Blue,' 'Azure Mist' and 'White Sparkle.'

I do recommend using these mostly in containers - our soil doesn't drain fast enough to keep them from rotting after one of our usual drenching rains. We grew them in full sun, but I recommend light afternoon shade.

You should be able to find these two lobelia cultivars in your local nursery this spring. Be warned though - they won't be cheap. They are patented and grown only by cuttings, so they're more expensive that the more common seed-grown varieties, but I believe the extra months of color they provide is worth it!