Coltsfoot (Tussilago farfara) is, in some areas, the very first flower of spring. Its charming yellow flowers emerge very early, often in February in mild climates, yet as late as May in cold ones.
The bright yellow blooms resemble dandelion flowers (Taraxacum officinale). Also, after they finish flowering, they also bear fluffy white seed heads like those of a dandelion. Add to that the fact the two plants belong to the same family, the Asteraceae, and you definitely have the potential for confusion.
In fact, many people do indeed take coltsfoot for a dandelion, at least while it is blooming. However, the two plants are in fact easy to tell apart.
Coltsfoot blooms on leafless stems that seem to arise directly from the soil. Its leaves only appear after the flowers have faded. When a true dandelion blooms, however, there is always a rosette of toothed green leaves at the plant’s base.
This curious habit of blooming well before the foliage appears lead to the Romans calling coltsfoot Filius ante patrem (son before father).
Two Different Plants?
The same people who mistake coltsfoot flowers for dandelion flowers are doubly confused when the leaves do appear: they think that the toothed more-or-less heart-shaped leaves belong to some other plant.
At this stage, it’s easy to confuse coltsfoot with the butterbur (Petasites hybridus), another common weed/medicinal plant, more common in Europe than North America, because their leaves are similar. For a long time, even taxonomists were confused. They originally called butterbur Tussilago hybrida, believing the two plants to be close relatives. Today, we know that they are only cousins several times removed.
The leaves are what give the plant the common name coltsfoot. With a bit of imagination, you can (sort of) see the shape as being that of a horse’s hoof… with teeth. To further distinguish coltsfoot from other pretenders, turn a leaf over and you’ll see they’re felty and white on the underside.
From Useful to Weedy
Coltsfoot is of Eurasian origin, but was introduced into North and South America as a medicinal plant over a century ago and has long since escaped culture and become a widespread weed, especially in clay and moist soils.
A pioneer plant, it often appears in disturbed soils, especially around construction sites. With its dense broad leaves, it chokes out native plants and sometimes comes to cover vast surfaces to the exclusion of any other plant. It’s a sun lover, though, and therefore it tends to gradually disappear as trees and shrubs move in and create dense shade.
Coltsfoot has a long history of medicinal use, especially as an antitussive. In fact, the name Tussilago comes from the Latin tussis (cough) and agere (to chase), because it’s said to “chase coughs”.
Even today, the plant remains very popular in herbalism, where both fresh and dried leaves, rhizomes and flowers are used as antitussives, demulcents, expectorants and tonics. The flowers and young leaves are edible and can be harvested as vegetables.
However, all the parts contain alkaloids that are toxic to the liver. The use of coltsfoot is therefore not recommended for people with liver problems or for pregnant or lactating women.
How to Control It
Coltsfoot generally arrives in gardens either through transported soil contaminated with rhizomes or through the air thanks to the silky hairs that carry the seed far and wide.
Once established, coltsfoot expands via underground rhizomes. As these can dip down to up to 10 feet (3 m) deep, obviously hoeing is not going to control coltsfoot. In fact, hoeing, cultivating or — worse yet! — using a rototiller often worsen the problem, as those tools tend to chop the rhizomes into pieces, yet any piece left in the soil will produce a new plant. Thus, often the more you cultivate, the faster coltsfoot spreads.
You’ll have more success to cutting back every leaf you see, repeating again and again. Just snip each one off at the base. That prevents the plant from carrying on photosynthesis, its only source of energy, and the inability to photosynthesize will gradually exhaust the rhizome. Or, more simply, cover the ground with a black tarpaulin or piece of old carpet starting in the spring as the leaves emerge, then leave this opaque cover in place for at least one year (two years may be necessary if the plant is well-established). Again, since it won’t be able to carry out photosynthesis, this will exhaust and kill the rhizomes.
Coltsfoot has the reputation of being difficult to kill with herbicides, but some people less environmentally concerned than myself have reported success by treating the young leaves with glyphosate.
So, is coltsfoot a beautiful harbinger of spring, a useful medicinal plant or a weed to eliminate? It’s all three, of course. How you see it depends on your attitude, your needs and your expectations.