Musk Thistle is a weed which mainly occurs on acreages and roadsides in various parts of the country due to their preference for sparse or degraded areas of soil. However, they can and do invade the home lawn as well, which most often occurs when a lawn has become degraded due to a current or previous drought, or perhaps lack of care by a previous owner.
For homeowners wanting to return their lawn to a state of good health and to be weed free, they may also need to control and kill any infestations of Musk Thistle, which is a nasty, prickly weed which can re-rproduce in great numbers if not effectively controlled.
Musk Thistle is biennial, meaning it's life cycle lasts over a two year period. It begins it's life as a seedling in Spring, and will turn into a rosette as the season continues. The rosette stage will last for the first season of it's life, and is recognizable by having many prickly leaves which spread out from it's center, and which lay low to the ground.
After Musk Thistle over-winters in the rosette stage, it will emerge the next Spring and begins the next part of it's growth by sending a vertical shoot up into the air which will eventually grow a flowers. This stalk is often called a Bolt. At it's maturity, Musk Thistle will produce several Bolts from each weed plant, each with a prickly stem containing a prickly pink flower at it's head.
The pink flowers can produce up to 20,000 seeds per plant, so it's important that these weeds be controlled as effectively and as soon as possible. Sometime treatments for Musk Thistle may last for several years if there has been a prior infestation of seeds into the soil.
Musk Thistle only spreads and reproduces itself from it's seeds. With this in mind, the greatest and easiest form of control is to never allow the Musk Thistle to create more seed heads which are formed from it's flowers. This can be easily done by cutting off or mowing over the top of the bolts, and placing the waste into the bin.
If the weed is producing flowers and seeds, this means the weed is in it's final year of growth and will die naturally, so there is very little else which needs to be done.
If it is noticed that there are Musk Thistle rosettes present, which are still in their first year of life, then a herbicide may be the best treatment method for the infestation. Herbicides are available for this weed, and manufacturers recommendations should always be followed for it's use. The best time to apply these herbicides is in the Spring or Fall
If the infestation of rosettes is only small, then the easiest and most environmentally friendly way of killing Musk Thistle is to simply get a sharp knife and cut it off below it's crown, which is the base of the plant, and the problem is solved.