Casual Gardener: Lucious lobelia requires special attention

The scarlet flowers of Lobelia cardinalis ‘Queen Victoria’
The scarlet flowers of Lobelia cardinalis ‘Queen Victoria’ The scarlet flowers of Lobelia cardinalis ‘Queen Victoria’

Lobelias come in a variety of shapes and sizes – with some more attractive to snails than others...

I'M long enough in the tooth to know that pride is inevitably followed by a fall, yet I couldn't help myself. On one of my recent regular visits to the (highly recommended) Byrne's Nursery near Downpatrick I came across Lobelia x specieosa 'Starship Scarlet', a relatively new hybrid half-hardy perennial.

It was the first time I'd seen this particular plant, which is not dissimilar to the more common Lobelia cardinalis 'Queen Victoria', sometimes known as the cardinal flower.

The latter I'm very familiar with; familiar enough to know that it's not the most robust and can easily succumb to attacks by snails. However, in recent years I've discovered that such attacks can be avoided if the plant is permanently located in water.

Last year I raised mine in a half-barrel, its roots contained by a submerged pot. The drawback here is that the plant's deep maroon foliage won't be quite as luscious as it would be were its roots in terrafirma but it's a sacrifice worth making if you're to avoid assaults by greedy gastropods.

Further research reveals that this is quite a common way to grow the cardinal flower, treating it as a so-called marginal and positioning it on the edge of a pond or stream.

When I enquired at the nursery if 'Starship Scarlet' could be deployed in a similar fashion, the ordinarily well-informed staff appeared a little perplexed, having been unaware that 'Queen Victoria' would prosper with its roots permanently moist.

And so it was with an obligatory degree of boastfulness that I enlightened them about the plant's versatility. Proudly, I regaled them with how mine had been raised in a half-barrel and was now residing at the side of my pond, at home among the flag iris, marsh valerian, ligularia and astilbe – marginals that thrive in water or damp soil. I returned to the car feeling much taller than my modest 5ft 7ins.

It seems more than mere coincidence but on arriving home and visiting the pond, I noticed that the Lobelia cardinalis, which up until this point appeared in robust health, had suffered a snail attack.

Snails are deceptively agile and will climb the equivalent of a skyscraper from where they effectively abseil onto the selected target. In this case a neighbouring ligularia had been used to gain access.

The outer layer of the slender stalks that would be capped by eye-catching scarlet flowers had been stripped, exposing the plant's unsightly green innards.

The damage wasn't as bad as I've previously seen – they can be completed destroyed on occasions – and I'm hopeful it will recover, however, it's unlikely to flower this year. On a more positive note, the Lobelia x specieosa 'Starship Scarlet' has spent the past fortnight in the half-barrel that successfully housed 'Queen Victoria' last year and appears more than happy to have its roots submerged.

Elsewhere in the garden I'm utilising Lobelia erinus, arguably the most common of the genus, a tender perennial grown as an annual with a trailing habit particularly suited to pots and baskets. It bears little if any similarity to its above namesakes; however, all lobelias are characterised by their plain, alternate leaves and two-lipped tubular flowers, each with five lobes. Notably, Lobelia erinus, the best varieties which include 'Cambridge Blue' and 'Waterfall', is rarely troubled by snails.