Gardener's mint turned pure black overnight, and commenters suspect herbicide, not heat

A gardener's alarming photos are gaining attention online after a thriving plot appeared to collapse in just a day. Even more troubling, the renter said a mint plant isolated in its own container had also turned "pure black."

What happened?

In a post on r/gardening, the renter said, "My garden started wilting yesterday and this is today's pictures. … I have a mint set off to the side in its own pot and its pure black now."

According to the poster, the weather had been around 90 degrees, they were watering heavily, and they had also added coffee grounds and eggshells to the soil. Many commenters, though, argued that the sudden, uniform-looking damage seemed less consistent with heat stress or disease than with chemical exposure.

"I would cry for days. This is herbicide/pesticide damage. Plants don't die this quickly or brown either even the thirsty ones. Someone came in and destroyed your garden, I am sure of it," said the top commenter. 

People also debated where the damage may have come from, with theories ranging from drifting weed killer to manure-based compost contaminated with persistent herbicides. Others suggested overwatering, chlorinated water, or heat from raised beds.

Why does it matter?

Chemical damage can show up quickly and be difficult to trace. If herbicide drift or contaminated compost is involved, the problem may not stay confined to a lawn or a single flower bed.

The gardener also said that unfamiliar people had recently been entering the yard, prompting some users to suggest installing cameras and raising the possibility of deliberate sabotage.

The discussion also pointed to a broader issue with conventional lawn care — chemicals used to keep grass looking tidy can sometimes affect neighboring spaces. 

By choosing a lower-maintenance yard option that requires less water, homeowners can save money and time on lawn maintenance while lowering water bills.

What can I do?

Commenters suggested the gardener seek out local help, with several saying the gardener should contact a local agricultural extension office for testing. They also warned that if herbicide contamination is confirmed, the soil and affected plants may need to be discarded rather than reused.

For renters and homeowners alike, it may also be worth asking neighbors whether any weed killer was recently sprayed nearby. If unexplained damage appears suddenly, documenting it with photos and, if needed, adding a camera can help establish a timeline.

Later, the gardener added, "Thank you so much everyone for the help!"

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