Joe Pye has a purple patch, so seek him out
Joe Pye weed is an American plant, named after a mysterious healer who used it in herbal remedies. It is a catchy name and easily remembered. The plant has tall stems with heads of small puffy purple flowers. Flowering lasts over a period of weeks from now. It is a magnet for butterflies that come to drink nectar from the flowers.
The pale purple flowers, opening from purple-red buds, offer a lovely contrast with the many yellow daisy-type flowers of this time of year, such as the helianthus, heleniums, inula and echinacea. It is native to damp prairies and grows in open woodland too. The correct botanical name, which is also used, is eupatorium.
It is very vigorous and grows to over two metres and makes a clump nearly as wide. So this is not really a plant for a small garden but it can look great in a large garden, especially near a pond. It can be used in a flower border too as long as it is matched with strong perennials of similar vigour.
There is a smaller form, aptly named 'Little Joe', that reaches only half the height of the species and this one should be able to find a place in small gardens. It has the same foliage and flowers as the bigger variety but the individual flower heads are not quite as large. Eupatorium looks very well with grasses, especially the taller grasses that are in flower now or coming into flower, such as miscanthus and golden oat grass.
There is a native eupatorium species, known by the common name of hemp agrimony, often seen in damp places by roadsides and in marshy ground over much of the country. It is pink or white rather than purple. But it is much too vigorous for garden use except possibly for semi-wild damp areas in a rural garden. It is also excellent for attracting butterflies, worth growing for this purpose alone. If the plants are placed in a sheltered spot where the air can warm up, it sometimes can have dozens of butterflies feeding.
There is also a shrubby form of eupatorium, evergreen, and covered in late summer with airy clusters of small white flowers opening from pink buds. Native to Mexico, this is not completely hardy and can be damaged during prolonged spells of hard frost. But it survives in many gardens in mild areas. It makes a broad bush up to three metres tall and wide. It is well worth seeking out.