A mammoth shade-garden hosta with thick, corrugated blue-gray leaves up to 18 inches long that slugs leave alone, topped by fragrant lavender flower spikes in midsummer.
Toxic to cats and dogs, which surprises people because hostas look so unthreatening and sit right at nose height. Eating the leaves causes vomiting and diarrhoea. Rarely serious, but a dog that grazes a whole clump will have a bad night.
For gardeners who like to stay ahead.