While a well-placed blackberry bush can bring joy to a grower who enjoys picking fresh blackberries and using them in pies or jams, sometimes a blackberry bush is unwanted. Full of thorns and a pain to mow around, blackberry bushes are a sore point for landscapers and homeowners who don't want to trade their hassle for berries. But they're not easy to get rid of. To truly remove a blackberry bush, you must to do more than mow over the bush, burn it or spray it with herbicide.
Clip away all of the stems that stick up from the ground by cutting them off at, or just above, ground level. Discard the top portion of the bush immediately to keep it from being left behind, for the plant will root wherever it is set down.
Start a foot away from the base of the bush and begin to dig the soil around it to create a large hole. Plan to dig as far down as 18 inches, if necessary, to get the bulk of the roots out of the ground.
Continue to dig the area until the entire blackberry bush is loose. Pull it from the ground and discard immediately. You'll want to remove as much root material as possible.
Pour two to three gallons of boiling water over the area to further kill off any remaining root system.
Allow the soil to dry thoroughly before tilling the entire area where the bush was rooted. Look for and discard any newly uncovered roots. Pour boiling water over the area one more time.