Three Types of Knapweeds

Noxious weed control in Arapahoe county, call or text (720)248-0000.
You know knapweeds are a problem. With that in mind, you need to take steps to minimize the growth, but do you know what knapweeds look like? There are three types of knapweeds that you need to be aware of.

Different types of knapweeds prefer certain growing conditions. You’ll also find them in specific areas. Here are the three types to look out for.

Diffuse Knapweeds

Initially introduced from Europe, diffuse knapweeds are usually found on rangeland, roadsides, and pastures. It’s the most common type found in Arapahoe County due to the natural of the land.
The plants can grow up to between 1ft and 3ft high, and that’s just from one stem. That single stem can produce multiple branches, which means a lot of buds to flower and produce seeds. It’s possible for one plant to produce 18,000 seeds, and those seeds can live in the soil without problems for up to 10 years.

The flowers are white, but they can sometimes turn purple. The purple flowers are often mistaken for spotted knapweed, but you can tell it’s a diffuse based on the sharp bracts at the bottom of the flower.

The plant is a short-lived perennial or a biennial one. It will kill off other vegetation in the area.

Spotted Knapweed

We’ve mentioned the spotted knapweed. This is the one with purple flowers and doesn’t have the sharp bracts at the bottom. It comes from Central Europe and has infested more than six million acres of the upper mid-west area of the United States. It loves rangelands, hillsides, waste areas, and riparian areas, usually doing the best in light textures soils that are well drained.

This is a simple perennial, regrowing from its own taproot. It can reach up to 4ft in height, and the bracts under the flowers will have dark spots. It is hairy, and between 1000 and 18,000 seeds are produced every year. It’s growing habits make it one of the hardest weeds to control.

Russian Knapweed

Another invasive weed from Europe, Russian knapweed is commonly found in waste areas, rangelands, roadsides, and croplands. It spreads fast and is very difficult to get rid of. It’s also highly poisonous to horses, so you’ll want to make sure you deal with it as much as possible if you have horses. The good news is there are few infestations in Arapahoe County right now.

While other knapweeds are purple, the Russian knapweed is pink in color. It can also sometimes look lavender or white. The bud and the flower’s base can look swollen, and there is an urn shape to it to make it stand out from other types. You’ll find it grows to between 1ft and 3ft in height.

SprayTech offers noxious weed control in Arapahoe county and surrounding areas. (720)248-0000.