How to clean growth between patio bricks?

Boiling water or vinegar will work. Non toxic, kid and pet safe, environmentally friendly and inexpensive.

You can also add salt to the water and vinegar mixture. Clean out the gaps of debri. Get some polymeric sand to fill in the gaps.

https://www.homedepot.com/p/SAKRETE-PermaSand-40-lb-Paver-Joint-Sand-65470004/202070568

Salt and vinegar is even faster, especially if the sun is shining. But I would clean the dirt out, too, with a wire brush after the salt and vinegar have killed the green growth. You may want to fill in all the spaces and cracks with lots of fine sand, up to the top of the bricks. This ought to work!

Hi Judy - This is the most effective all-natural weed killer DIY that we use. It's even been featured on Hometalk! Hope this helps! Hugs, Holly

https://pinkfortitude.com/weed-killer/