Don’t worry about a dusting of wildfire ash on your garden — just wash it away

Ash can be a useful nutrient for garden soil.
(Ross May / Los Angeles Times; Getty Images)

It seems like California’s wildfires have left a coating of ash on everything, including garden plants. But there’s no reason to panic, said Master Gardener Yvonne Savio of Pasadena.

Pot ash is actually a source of potassium and can be a useful nutrient for garden soil, said Savio, who offers advice at

However, a buildup of ash on your plants will literally block the sun from helping the plant perform photosynthesis, which helps it create leaves, flowers and fruit.

Keep your houseplants healthy during record heat with these tips.

Sept. 9, 2020


The solution is simple, Savio said: Just take a garden hose and gently spray the ash off your plants. The ash will fall onto the soil, where it can do some good, and the plants will once again have full exposure to whatever sun can be found peeping through the smoke.

Large amounts of pot ash — that is, ash from wood-fueled fires — can increase the alkalinity in the soil, but a light dusting shouldn’t be a problem, she said. If you’re spreading ash in your garden, sprinkle it around and gently fork it into the soil so you don’t create any concentrated areas of alkalinity.

His East L.A. backyard is mostly concrete, but Ken Sparks has transformed the hardscape into something alive, with chickens, a butterfly garden and organic vegetables.

Aug. 19, 2020

In fact, wood ash from your fireplace or outdoor fire pit can be added in the same way to your garden soil or compost pile, Savio said.

One proviso: Keep the ash from charcoal fires or wood fires started with lighter fluid away from your soil, because the chemical accelerants in those products are bad for your garden, Savio said. “That’s a whole different chemistry going on in a charcoal briquette.”