Thursday, May 4, 2023

Blue Mustard by CMG Brenda Sterns

Photo:  Brenda Sterns

Purple Mustard, Blue Mustard or Crossflower Chorispora tenella  

With the arrival of spring, the days are getting sunnier and warmer, and the trees and ground are showing tinges of green.   Excited to see what’s growing, you stroll through your yard and come across a petite, four-petal flower in shades of purple or pink. Perhaps you've seen it before, or maybe it's your first time noticing it. 

Intrigued, you decide to take a closer look and find that it has a musky smell. Chances are, you have Purple Mustard growing and enjoying the season's warmth and sunshine. 

The plant is native to Eurasia, and has become an invasive weed throughout most of North America.  Purple Mustard is hardy and can grow in various soil types including disturbed areas, pastures, fields and alas your flower beds.  Purple mustard, which is a winter annual, starts out as a rosette, and then elongates as it actively grows to produce a single stem with multiple flowers. The petite flowers form a distinctive cross shape.  In my gardens, I notice new plants germinating in February or March then blooming around April.  Unfortunately, the seeds are viable for years, and will wait out drought years before germinating.   

So, what do you decide to do?  Pluck it out (easy to do as the plant has a weak root system) or let it grow?  That can be a tough decision to make as some people enjoy the smell and don’t mind seeing the purple flowers across the fields.  A natural bonus for such an early blooming plant is that bees can find nectar that they need after hibernation. 
Photo: Brenda Sterns

For me and my pasture, I find the plant to be invasive and can choke out other native plants like grasses.  Even my llamas avoid eating this plant.  Currently, the musky smell is noticeable in my neighborhood as the plants are coming into bloom.  I have already pulled out my hula hoe a few times and started hoeing out the thick patches of Purple Mustard. 
If you are interested in various control methods beyond pulling out the plants, check out the PlantTalk article: