Living in California, we inevitably get smoke from wildfires in our yards and gardens and this year is no exception. Over 7,400 fires and 3.1 million acres have burned across California so far this year, making 2020 an extreme year for fires on top of COVID-19, protests, an election, and heat waves. But how does all of this smoke and ash affect our plants? I did some research and found that there are both positive and negative effects of smoke on plants.

Positive effects of smoke come from the increase of carbon dioxide. Plants extract carbon dioxide from the air and use it in photosynthesis to feed themselves. If the plant has an ample supply of water and there is enough sunlight shining through the smoke for the plant to use the extra carbon dioxide, the plant can produce more food for itself. At moderate levels smoke can diffuse the light, which can be a relief for plants here in the high desert that are normally exposed to very intense light every day. This is good for the plants but also for us humans and animals who depend on oxygen.

Conversely, smoke and ash particles can coat plants inhibiting photosynthesis. Smoke particulates can clog stomatal pores which prevent the gas exchanges required in photosynthesis which decreases the amount of food available to the plant. Smoke that sticks to plants can be bad for the plants but good for us. Plants, especially fuzzy plants, remove these smoke particles from the air by absorbing them into their leaves and stems and by minerals translocated through the roots. Again, this eventually helps clean the environment.

If plants are covered with smoke and ash, both sides of their leaves should be cleaned with water. As for the produce you eat from your garden, simply washing it with water before consuming it should remove any of the residue you might otherwise ingest.

In conclusion, the good news is that your plants will likely not be harmed by the smoke, especially if you give them a bath. The bad news is that the smoke is still hazardous to us humans.

Luckily, we have the plants to help us out by cleaning the air for us.

Humans can find out current air quality conditions online at airnow.gov.