I have grass growing up between the bricks on my patio. Is there a way to kill it off?

Roundup is a pretty popular brand of weed and grass killer to use.

Roundup Weed and Grass Killer - Google Search

There are also some organic ways to kill unwanted grass.

Organic Grass Killer - Google Search

Use round up.

All three of us agree to use Roundup. There are several versions of Roundup so read the label, you want the plain grass killer, not brush, not hard to kill, not year long.

Non-toxic solutions would be to hand pull the grass, use a weeder to uplift it. Pour boiling water over the grass saturating it thoroughly down to the roots. Use a torch to burn the grass to its roots. But make sure that the boiling water or the fire will not change or affect the bricks in a way that will disappoint you. Also if you can find a vinegar of 20% acidic acid, thoroughly soak the grass at high noon while the sun is shining on the grass in your patio. Remove all soil and seal the seams of the bricks.

Premium choice! Way more ecologic then the previous answers.

Our brick paths were left with sand between the bricks. We tried chemicals, but the weeds always came back. The only permanent solution is to point between. Method

Remove all weeds and roots
Rake out 1" deep
Tamp down
Point with a mixture of 2 parts cemetn to 3 parts building (not sharp) sand
Profile the mortar with a Frenchman tool. It is better if there is excess morta so that it squishes out a bit
After 12 to 24 hours carefully remove the excess mortar to the level of the bricks with a small paint scraper