Garden fruits and vegetables showered with ash from wildfires should be safe to consume, according to Oregon State University Extension Service experts.
Rinsing produce outside and then again in the kitchen sink helps 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, Brooke says. 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 decide.
“Use your best judgement,” Brooke says. “If your garden has a heavy layer of ash or is near a structure that burned, the risk is higher. Burning buildings contain different toxins than a forest.”
In addition to rinsing, Brooke advises peeling produce such as 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—1 cup vinegar to 9 cups water—which can lift soil particles off vegetables such as kale, Swiss chard and savoy cabbage, and fruit such as peaches, apricots and nectarines.
Avoid going outside to harvest while smoke lingers, Brooke says. When air quality improves, wear a mask to help filter any residual ash.
The closer your garden is to a fire, the larger the chance the soil may be contaminated. To determine the amount of chemicals that seeped into the soil, consider doing a soil test before planting the 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 “Get Actionable Results from a Soil, Plant or Environmental Testing Lab” is a good resource. Visit tinyurl.com/356f8vvh.
Mapping the food-growing area and soil sample spots allows you to correlate your test results and identify spots of concern if 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 reduce the chance that soil splashes on plants, especially leafy green vegetables. You can use a landscape fabric or weed cloth as a barrier between soil and mulch.
When there is ash after a fire, avoid kicking up soil as you walk through it. Do not use a leaf blower to clean anything outside, including plants, cars, patio furniture and sidewalks, so you don’t breathe in ash. Instead, use a gentle stream from a hose.
Finally, if you have a thick accumulation of ash, consider amending 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, are appropriate to add to areas of low-level contamination. However, it’s not necessary for most people to amend.
For more information on food safety and wildfires, visit tinyurl.com/ya263265. Information courtesy of Oregon State University Extension Service.