Cunjevoi

Tiger lily (Lilium lancifolium) is the lily you should think hardest about before planting, and the reason is not the plant itself. It is a near-universal symptomless carrier of the lily virus complex, above all cucumber mosaic virus, the pathogen gardeners know as lily mosaic. Tiger lily shrugs it off and looks perfect while carrying it; aphids move it to the Asiatic and Oriental hybrids nearby, and those streak, mottle, distort and decline with no cure available at any price. Missouri Botanical Garden's own note on the genus is blunt about that asymmetry: prompt aphid control is highly recommended, since there is no cure once infection occurs. The long-standing advice in lily circles follows from it - keep tiger lily well away from other lilies, or do not grow it at all near a collection you care about. Everything else about the plant is easy. It is a 3-to-6-foot stem-rooting lily with nodding, unscented, orange flowers heavily spotted in near-black, recurved right back on themselves, opening in July and August. It is one of the toughest lilies in cultivation, hardy well into the cold north, and it is the only common garden lily that reproduces from BULBILS - small purple-black bulbs formed one to three at a time in the leaf axils, which drop, root and become new plants. The North American plants are almost all sterile triploids, so seed is not the story; the bulbils are, and they are also how it escapes. Kew's rows flag forty-one introduced occurrences, from Alabama and Louisiana to Maine and Ontario and across much of Europe and Russia. Two more things belong on the label. Every lily in this group is severely toxic to CATS, including the pollen. And Lilioceris lilii, the scarlet lily leaf beetle, has spread across the northeast and eastern Canada and will strip this plant to bare stems.

The stately, classic tall border perennial - the parent of the great Elatum-hybrid delphiniums - grown for towering, densely packed spires of spurred flowers, most famously an intense pure blue (also purple, white, or pink), each bloom centred on a contrasting tuft of petals known as the "bee." It rises on tall hollow stems above deeply palmate-lobed leaves and flowers in early to mid summer. Magnificent but high-maintenance and load-bearing in its honesty: the tall spikes need staking and shelter from wind, the plant is hungry, thirsty, fairly short-lived, a slug magnet on its emerging shoots, and it dislikes hot, humid summers, performing best in cool-summer climates. It is also HIGHLY TOXIC in all parts (diterpenoid alkaloids), and the sap can irritate skin - which is also what makes it reliably deer-resistant. POWO (Kew) places it native to the mountains of Europe across to Siberia and central Asia; RHS rates the species fully hardy (H7) and has given the Award of Garden Merit to many of its hybrids.

Ligularia dentata (leopard plant, summer ragwort) is a bold, moisture-loving herbaceous perennial native to China and Japan, grown for its enormous, glossy, heart-shaped toothed leaves and bright orange-yellow daisy flowers on dark red, near-leafless stalks in mid- to late summer. It makes an outstanding focal point beside water or in a shaded border, where its tropical-scale foliage dominates from spring through autumn. There are two honest catches: water - in full sun or any drying wind the giant leaves wilt dramatically by midday (they recover overnight, but the spectacle is ruined), so consistent moisture and afternoon shade are non-negotiable; and toxicity - like its Senecio relatives it contains hepatotoxic pyrrolizidine alkaloids and is not edible.

Rodgersia podophylla is a bold, large-leaved herbaceous perennial native to the damp, shady forests of Japan and Korea, grown primarily for its dramatic palmate foliage - bronze at emergence, green through summer, and flaming bronze-red in autumn, with frothy creamy-white flower panicles in June and July. It suits the moist shade of a woodland garden or poolside planting where it anchors a composition with architectural scale. The honest catch is its rhizome: Rodgersia spreads underground and, given time, covers a large area, so site it where expansion is welcome or install a root barrier at the outset.