what plants can we grow at home to keep accidents and mishaps at bay?

As far as I know there are no universally protective herbs but here are a few suggestions I've found.
1. Sage can be used as a ritual cleansing.
2. Agrimony can be burned in much the same way as sage or you can sprinkle it around our house to send bad spirits back o the sender.
3. Ague Weed, also known as Boneset can be added to your bath water to banish evil spirits.
4. Angelica is sometimes used in formal exorcism to get rid of bad spirits.
5. Broom can be boiled in salt water to keep ad spirits at bay.
6. Cedar, burned as incense will protect your house from evil spirits.
7. Rue can be burned to protect the house from bad energies.
Do a little research on Google to find more info.

sorry for the late reply. thank you so much for the helpful advice. thanks a lot.

Sweetgrass is also a good herb to use for house clearing and blessing, along with the sage and cedar.  Other good ones are rosemary, cinnamon, clove, cedar, sandalwood, myrrh, and cypress oils.  All of these herbs can be used separately or combined.  They can be put around the doorways and windows so that the room is cleansed and then negativity can not enter into it.

Herbs can also be brewed into a tea and used to sprinkle a room, and carpets can be misted by using a spray bottle.  Another thing that is beneficial is to mop the floors and then go over them a second time with an herbal wash of the teas.

Also, a small amount of sea salt can be "blessed" and added to the teas. You can just bless a pound of salt, as well as the herbs and oils by saying a prayer over them, something like this:

(Deity or deities... i.e., God, Goddess, etc.) Bless and make sacred these herbs and oils. May all negativity be removed... remove all sorrow, misery, poverty, ghosts, demons, spirits and harmful energies of all types and shapes. May the (deities) be able to remove all energies of negativity and evil through out all time and space, all dimensions, all realities, whether they are known or unknown by the person now doing this ceremony. I ask (deity or deities) for their blessings and energies on this salt, and on these herbs and oils to nullify, destroy, and remove all negativity and release all spirits to their realms of existence and the light. So Be It