Sow thistle (Sonchus oleraceus) is an annual herb, from the daisy family, which is native to Europe and Western Asia. However, it also grows in several other regions around the world. It is particularly common in California, where it is treated as an invasive weed.
The species is known by many alternative names. For example, sow thistle, milky tassel, milk thistle, soft thistle, and swinies. It shares many aesthetic characteristics with the dandelion, and the two are often confused. They prosper in similar conditions, seeming to prefer the disturbed soil found in gardens, flower beds, cultivated ground, and wasteland.
Like many other broadleaf weeds (for instance, red sorrel), the leaves of this plant are safe to eat. They can be eaten raw as a salad ingredient or boiled to remove the bitter flavor. Sow thistle is a popular addition to Chinese dishes.
The plant poses few problems for weed control and lawn maintenance strategies, as it can be easily removed with mowing. It is not able to regrow from fragments, so a medium intensity lawn care routine should be sufficient. As the seeds need light to germinate, covering the ground with a thin layer of mulch is a good way to prevent new plants from forming.
If you think that there may be sow thistle growing in your garden, look for the following features. The mature sow thistle plant can grow to around 1.4 meters. Its stem is smooth and fairly thick. If broken, it leaks a milky white sap. The leaves are similarly smooth, with a green body and a slightly purple/blue tinge at their edges. They typically grow to between 4 and 8’’ long.
The flowers usually appear in the spring and summer, but if the plant gets lots of sun, they can remain all year round. They grow in clusters at the top of the stem and are a bright yellow. Like dandelions, the flower heads mature into fluffy white seedlings. However, they are more of a crescent shape than a ball, like the true dandelion.
If you want to guarantee the removal of sow thistle from your garden, it is a good idea to seek the help of a reliable lawn service that can purchase commercial grade weed control products. For older people and those with limited mobility, this can be a valuable option.