For long flowering and general reliability the Rudbeckias rank highly for adding brightness in the garden in late summer and autumn, even though all are in shades of yellow. R. deamii will flower in great profusion from late July into October with its black centred rayed. The height is 2-2½ feet, a little taller than the deeper yellow R. ‘Goldstwm’, which in good soil will flower for an even longer period. These supercede the old R. speciosa and there are taller, grey leaved species in R. subtomentosa and R. mollis, which grow 3-4 feet flowering July-September. The foregoing Rudbeckias are mat forming in the sense that they do not have a deep, compact system, but a more shallow rooting outward spread. Nearly all such plants are of a hungry and thirsty disposition and when plants have been down for about 3 years, covering a much wider space, they may show some deterioration in the centre of the plant with less foliage and fewer flowers. The remedy is to apply some fertilised soil in that centre or to take up and replant using only the outer, more vigorous growth. R. ‘Goldquelle’ is outstanding for its erect bushy habit, well clothed with deep green , and set with fine double chrome yellow flowers from early August into October. The height is little more than 3 feet, and a far tidier plant than the tall, floppy R. ‘Golden Glow’. The best tall variety is single flowered R. ‘Autumn Sun’, but even this will reach 5 feet or more. All these Rudbeckias will divide in early spring and will flower for longer in good soil, not too dry; than where starved. See under Echinacea for what is still sometimes called R. purpurea—the ‘Purple Cone Flower’.