Remove Thorns from Dangerous Hill

Question from Howard:

I live in Redondo Beach California and I have a thorny plant that is invading a hill area near my condo. As chairman of the landscape committee I have been asked to remove the thorn bushes. I am concerned about the steep hill. Can you tell me what it is and how to remove it or even if we should. It is large over 6 feet high and has inch long twin thorns. I don’t know what it is or how to deal with it. The hill is important as we are concerned with mud slides. Individuals here want to use Weed-B-Gon but I am against it. If I use the herbicide will the hill be replantable after the treatment. It is important to keep the dirt from slipping, perhaps I will leave it alone however it is blocking the view and the thorns are dangerous. Can I send you a pic. How do I remove it?

Answer from Pat:

Bullshorn Acacia (Vachellia cornigera) has twin thorns. Is that what you’ve got? I do not suggest herbicides. Better to cut off the plant down to the ground. Use a stump killer on the cuts. This way the roots will hold the earth and you can plant something else on top to shade out the acacia.