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Plant of the Month: Lobelia hybrid

Techno Heat & Waterfall Series

Lobelia hybrid ‘Techno Heat’(tm) series and ‘Waterfall’(tm) series

At a glance:
Latin Name: Lobelia hybrid ‘Techno Heat’(tm) & ‘Waterfall’(tm) 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’(tm) series from Fischer and the ‘Waterfall’(tm) 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’(tm) series comes in three colors: ‘White,’ ‘Upright Blue’ and ‘Light Blue.’ ‘Waterfall’(tm) 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!

If you would like more information about the Dallas Arboretum Plant Trials, visit our Web site at