Russian Thistle – Also known as Tumble weed.

This is an annual herb, not a weed, but most states have this categirized as a weed.  It will grow to be .5-6 feet tall.  These weeds can be found almost year round in the southwest.  It can grow in elevations between 150 – 7,000 feet and ususally flowers May to Oct or Nov.  This weed seeds out to spread.  As the plants dry out they break off at the base and start to blow around spreading it seeds.  They are known as ‘tumble weeds’ after they break off.  Glyphosate is the best product to control this.  To prevent this weed or herb use a premergence.

Milk Thistle – From the Thistle Family

This weed can be both an annual and biennial weed. It will grow to be 2 to 5 feet tall.  These weeds are common March thru August.  It grows in elevations usually between 1,000 to 3,500 feet elevation.  This weed has many spines in the leaves.  It has flowers that are purple in color.   Some say this weed contains nitrates at a toxic level but it is not common enough to cause issues in Arizona.  It can be prevented by a pre-emergent.  Some selective herbicides and glyphosate will also control it.  Please dont abuse the comment section on this blog or they will be disabled because I dont have time to personally approve every message.

Thanks, The Weed Control Guy.

Common Mallow – From the Mallow Family. This weed can be both an annual and biennial weed. It will grow to be 1 to 3 feet tall. The weed grows from the base. It has large leaves that alternate and are round in shape. They have a red spot at the base of the leaf. The weed does have small flowers. The flowers are blue or pink. The plant spreads by seeding out. It can grow year round with water but will usually die in areas not watered. It can be prevented by a pre-emergent. Some selective herbicides and glyphosate will also control it.

London Rocket – From the Mustard family. This weed is a winter annual and usually dies when the temps rise.  It will stay around longer in shady moist areas.  The plant is green and the flowers are yellow.  The plant grows to a height of up to 3 feet.  It can be controlled with some selective herbicides.  No need to use glyphosate for control. To prevent this weed from taking over use a pre emergent two times a year, especially in the south.