Erigeron: species, confusion & control as weed
When the erigeron fades, the white flowers turn pink, bringing more colour to the greenery – making it a real eye-catcher for the garden.
The genus Erigeron features colourful flowers and a fast spread. This makes for wonderful groundcover and can allow establishment through seeding – however, it can also quickly turn some species of Erigeron into weeds. So should we tackle the Erigeron, and if so, can we do so in an environmentally friendly way? Read here how to recognise Erigeron, distinguish it from other plants and what species and varieties the genus contains.
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Recognising erigeron: characteristics and origin
The genus erigeron includes about 400 different species distributed primarily in temperate regions of the northern hemisphere and in North America. In Central Europe only 3 species are native, and 3 Erigeron species have been introduced to Europe as neophytes. The composite plants are also known as daisy erigeron or showy erigeron. Erigeron includes annual, biennial, and perennial herbaceous species, all of which are evergreen. The flowerheads are on erect stems with alternate to rarely basal stem leaves. The leaf blades are entire to toothed or divided. The flowers of Erigeron can have different colours depending on the species and variety and consist of fertile tubular and sterile ray florets. The ray florets lie around the outside of the tubular florets which are half as long in size. The centre of the flower is usually yellow. The composite plants form achene fruits after flowering, which spread by flying umbrellas.
Tip: The common name fleabane comes from the belief that the plant can drive away fleas. It was used in the Middle Ages to fight diseases, the origin of which was attributed to the black magic of sorcerers and witches. It is also said to have been placed in the cradle of children to protect against evil spells.
Is erigeron bee friendly?
Yes, erigeron is quite bee friendly and provides moderate amounts of pollen and nectar for butterflies, bees and other pollinators. However, the filled varieties are not insect-friendly. Important: Our native insects are, of course, primarily adapted to the native Erigeron species. So these perennials are best suited to the needs of the fauna of your garden. Below you will find the description of the species with a note in each case on the origin.
Danger of confusion with erigeron
Recognising the erigeron can sometimes be difficult, as the species of the genus are easily confused with other plants. Here are some plants that visually resemble the erigeron:
They are particularly similar to the aster. This sometimes leads to confusion.
Erigeron is also easily confused with the daisy (Bellis perennis). However, daisies have basal and smooth-edged foliage and grow no more than 15 cm high.
Confusion with camomile is also possible, the latter having divided leaves and broad ray florets.
The oxeye daisy (Leucanthemum vulgare) looks similar to the erigeron. However, their flower heads are about 5 cm wide and they have broad, white ray florets. In addition, its stem is unbranched.
Species and varieties at a glance
There are many species of the Erigeron. Here you will find the most popular species for the garden and those that occur in the wild.
Erigeron in the garden
In the garden at the moment, unfortunately, there are mostly non-native species of Erigeron. We present some beautiful varieties of these here:
Erigeron karvinskianus: Common name: Mexican fleabane; white ray florets, turning pink as they fade; self-seeding; annual erigeron; up to 20 cm tall; best growth in sunny to semi-shady sites with well-drained and dry substrate.
- Erigeron karvinskianus ˈProfusionˈ: Up to 20 cm high.
- Erigeron karvinskianus ˈSea of Flowersˈ: Up to 30 cm high.
Erigeron glaucus: Common name: beach aster; hardy species; bright purple ray florets; leathery, thick leaves; to 20 cm tall; best growth in off-sun locations with well-drained and fresh substrate; native to the U.S. West Coast.
- Erigeron glaucus ˈAlbusˈ: White tongue flowers.
- Erigeron glaucus ˈSea Breezeˈ: Pink tongue flowers, suitable for coastal sites.
Apart from these variants, there are other hybrids of the erigeron. Parent species include Erigeron pumilus, Erigeron glabratus, Erigeron glabellus and Erigeron atticus. For these varieties, the flowering period is between June and August, and they can be used as cut flowers. They grow best in off-sun locations with well-drained and fresh substrate.
- Erigeron speciosus hybrid ˈDunkelste Allerˈ: Dark blue, up to 60 cm tall.
- Erigeron speciosus hybrid ˈSommerneuschneeˈ: White, height to 60 cm.
- Erigeron speciosus hybrid ˈRosa Triumpfˈ: Pink, double flowers, to 60 cm high.
- Erigeron speciosus hybrid ˈGartenmeister Walterˈ: height to 80 cm and pink-salmon colour.
Wild erigeron
Representatives of wild erigeron can be found in the garden and along the path as well. Some are more of a nuisance to our flora, others are native wild species.
Erigeron acris: Also known as bitter fleabane; native throughout Europe; small, white flowers; globose, straw-white pappus fruits; green overwintering; to 70 cm tall.
Erigeron annuus: Common name: tall fleabane; from Central and North America; invasive neophyte with heavy spread; panicle of small, white aster flowers; hairy stems; blooms from June to October; to 170 cm tall.
Erigeron uniflorus: Native to Central Europe; purple-white ray florets; to 12 cm tall.
Erigeron alpinus: Native to Central Europe; pinkish-red, multi-rowed ray florets; height to 20 cm.
Erigeron canadensis: Common name: Canadian fleabane; invasive neophyte with heavy spread; short, whitish ray florets; blooms July to October; to 100 cm tall.
Erigeron strigosus: White ray florets; to 100 cm tall; native to Central and North America.
Erigeron philadelphicus: Common name: Philadelphia fleabane; white flowers; up to 70 cm tall; pretty to look at; spreading on the European continent for a few years.
Should you control erigeron as a weed?
Annual erigeron (Erigeron annuus) is considered problematic because of its vigorous dispersal by its seeds. The invasive neophyte is a particular problem in agriculture, as it can reduce yields. The same sometimes applies to the private garden. Accordingly, in beds it may be useful to control the erigeron as a weed and at least prevent its further spread.
However, to combat annual erigeron, it is not necessary to immediately resort to chemical means. The most efficient way to prevent the plant from spreading is to uproot it, roots and all, before it blooms. You should do this at least once a month, preferably when the soil is moist and with the help of a weeder. If erigeron has already spread and large stands are present, it is important to prevent it from going to seed by mowing regularly before flowering.
Tip: You should be careful when disposing of annual erigeron. In the compost, the plant must be disposed of without buds, flowers or seeds, otherwise it can spread there again. These parts can be disposed of with the green waste.
Is erigeron poisonous?
No, the erigeron is not poisonous, in fact it is even edible. The species of Erigeron are also not toxic to pets such as dogs and cats. The annual erigeron is said to have medicinal properties in homeopathy. Prepared in tea, the infusion is said to have an expectorant effect and raise body temperature.
If you are not sure whether you have erigeron, or even aster or camomile in the garden – there is more detailed information about these plants in our magazine.
