ash on tomatoes

CORVALLIS, Ore. – Fruits and vegetables in the garden that have been showered with ash from wildfires should be safe to consume, according to Oregon State University Extension Service experts.

Rinsing the produce outside and then again in the kitchen sink will help remove ash and the particulates that accompany it, according to Brooke Edmunds, associate professor and Extension community horticulturist in the OSU College of Agricultural Sciences.

Ash and smoke are unlikely to penetrate fruit and vegetables, Edmunds said. However, safety becomes more of an issue the closer you are to a fire. Note how much ash collected on your produce and the health of your plant to make a determination

“Use your best judgement,” Edmunds said. “If your garden has a heavy layer of ash or is located near a structure that burned, the risk is higher. Burning buildings contain different toxins than a forest.”

In addition to rinsing, Edmunds advised peeling produce like tomatoes, apples and root crops and stripping the outer leaves of lettuces and other greens. For a more thorough cleaning, soak vegetables and fruits in a 10% white vinegar solution (one cup vinegar to nine cups water), which can lift soil particles off vegetables like kale, Swiss chard, savoy cabbage and fruit like peaches, apricots and nectarines.

Avoid going outside to harvest while smoke lingers, Edmunds said. When air quality improves, wear a mask (an N95 is best, but if you can’t find one due to the shortage, wear a cloth one with a filter) to help filter any residual ash. You can find the latest air quality information at AirNow. Avoid tracking ash into your house on shoes by removing them outside. Clothes can also carry smoke and ash into the home, so change and launder them as soon as coming inside. And don’t forget to wash your hands.

If fire comes close to your home, think about taking additional precautions, Smoke, fumes and heat affect food even if the home seems well sealed. Smoke can enter through the smallest openings, including around windows and doors.

In those conditions, OSU Extension food safety experts recommend replacing:

  • Food stored at room temperature like potatoes, fresh fruit and vegetables and dried fruit in open containers in cabinets and on shelves.
  • Food such as meats and dairy products in refrigerators and freezers that have been contaminated – fumes can enter through seals that may not be airtight. If food has an off-flavor or odor when it’s prepared, toss it. Always err on the side of caution.
  • Food packaged in cans or jars that have been exposed to temperatures over 95 degrees. Cans that are split or ruptured or have visible signs of damage.

Food in metal cans that are commercially sealed, undamaged, unopened, waterproof and airtight can be considered safe once they’re disinfected. First scrub the can with detergent and then submerge it into a mixture of chlorine bleach and water. The Centers for Disease Control and Prevention recommends one cup of bleach to five gallons of water. When finished, make sure to label the can.

Heat can cause jars and cans to split and crack, allowing germs to enter. Even if undamaged, heat can cause food to spoil. Smoke and chemicals from a fire can potentially poison foods and firefighting chemicals can taint foods. Find more information at Food Safety and Wildfires, a resource from the Western Regional Center to Enhance Food Safety in the College of Agricultural Sciences.

The closer your garden is to a fire, the larger the chance the soil may be contaminated, Edmunds said. To determine the amount of chemicals that seeped into the soil, consider doing a soil test before planting next spring. Collect soil samples from several areas, label them with the spots where they originated and send them to a lab. The OSU Extension publication Analytical Laboratories Serving Oregon is a good resource.

Mapping the food-growing area and soil sample spots allows you to correlate your test results, and identify spots of concern in case you need to do more testing, according to the UC Cooperative Extension of Sonoma County, California. Ask the lab for a heavy metals panel analysis that includes lead, cadmium, arsenic, nickel and mercury.

Other actions to take include washing off plants in the garden with a hose, mulching and using drip irrigation or soaker hoses to lessen the chance of possibly contaminated soil from splashing on plants, especially leafy green vegetables. A landscape fabric or weed cloth can be used as a barrier between soil and mulch. Avoid kicking up soil as you walk through it. It’s very important not to use a leaf blower to clean anything outside, including plants, cars, patio furniture and sidewalks, so that you don’t breathe in ash, Edmunds said. Instead, use a gentle stream from a hose.

Finally, if you have a thick accumulation of ash, it’s not a bad idea to amend your soil with compost or a “clean” soil mixture from bags or in bulk from a soil amendment outlet. According to UC Sonoma Extension, some research suggests soil microbial and fungal populations, which help break down organic chemicals in soils, would be appropriate for low-level contamination. However, it wouldn’t be necessary to amend for most people.


About OSU Extension: The Oregon State University Extension Service shares research-based knowledge with people and communities in Oregon’s 36 counties and the Confederated Tribes of Warm Springs. OSU Extension addresses issues that matter to urban and rural Oregonians. OSU Extension’s partnerships and programs contribute to a healthy, prosperous and sustainable future for Oregon.Brooke Edmunds, 541-730-3470, [email protected]






Extension Service

About the OSU Extension Service: The Oregon State University Extension Service shares research-based knowledge with people and communities in Oregon’s 36 counties. OSU Extension addresses issues that matter to urban and rural Oregonians. OSU Extension’s partnerships and programs contribute to a healthy, prosperous and sustainable future for Oregon.

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By Kym Pokorny, 541-737-3380, [email protected]


Brooke Edmunds, 541-730-3470, [email protected]


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