Heat-proof lobelias

Plant breeders are a restless group, revisiting plants they’ve previously improved to see what more can be accomplished. I’m a great fan of annual lobelia (Lobelia erinus), available with intensely blue cascading flowers for hanging baskets or as an upright form that makes a colourful border around a large container. I was entirely satisfied with the plants, although a blast of summer heat usually fried them, and the withered remains had to be removed in midsummer.

Thanks to a second generation of breeding work, we now have hybrid lobelias with stronger resistance to heat and the ability to bloom from spring planting right through summer, up to frost. Heatproof Proven Winners Lucia and Laguna cultivars, and Magadi lobelias are interspecific hybrid strains. Interspecific hybrids are a combination of genetic traits from different lobelia species. Another plant example is California blackberry (Rubus ursinus or boysenberry), resulting from a three-way crossbreeding of common blackberries (R. fruticosus), European raspberries (R. idaeus) and loganberries (R. x loganobaccus).

The difference in these new hybrid lobelias is apparent, even when still in their nursery pots. The plants are more vigorous, their foliage is slightly larger with thicker stems, and the flowers are also somewhat bigger. The plants look robust and less delicate than the heat-sensitive lobelias I’ve been growing, but they still retain the usefulness of a companion plant for small spaces. However, their robustness makes it possible for them to carry the show alone, with three or four pots filling a hanging basket or patio container.

I picked up some pots of Magadi Blue, a beautiful deep blue with white central blotch. The Magadi strain will satisfy blue-obsessed gardeners with Dark Blue, Ocean Blue and Electric Blue; there’s also Dark Purple and Compact White. Proven Winners Lucia and Laguna strains have flowers in Dark Blue, Compact Blue with a white eye, Sky Blue, Lavender Blush, Heavenly Lilac and White. These lobelias could also be used for making beautiful mounding groundcovers in small garden areas for a reliably long season of display.

This time, a second generation of plant breeding has resulted in a win-win circumstance for lobelias.