Ultimately, the goal for prevention is to eliminate anything you can that could fuel the fire. And while one person making these changes won’t save a whole community from burning down, spreading this information to others in your community and encouraging them to implement these strategies can create a fire resistant landscape.
Protect Your Garden and Harvest from Wildfires
While the ash from trees can actually improve gardens, that’s not the only ash you’re getting in a wildfire. Ash from buildings made with conventional construction materials are laden with chemicals you don’t want in your food. While the construction ash is diluted with the forest ash, you’ll still want to take every precaution you can to reduce chemical contamination.
Cover your garden. If you can, cover your garden with clear or translucent plastic. If you have season extension low tunnels or cold frames over your garden beds, use this to cover the top and reduce ash debris. It won’t eliminate the ash you’ll get from wind drift, but it will help.
If you don’t have season extension, even covering your garden area with a waterproof tent can reduce chemical ash exposure. Enclose the tent on all four sides but leave the side covers a foot or so off the ground to allow enough air to get in and circulate. Adding a small fan inside the tent will help your plants get the air circulation they need.
Not everyone can cover their whole garden. If this is the case for your situation, you can vastly reduce the amount of ash your soil absorbs by laying plastic weed barriers down on the soil.
Dust wildfire ash off your garden plants. If you notice large amounts of dust on your plant leaves, you’ll want to remove that to make sure the plants can transpire as needed. Dust will block the pores of the leaf (called the stomata) and prevent the plant from cooling. It will also affect the plants ability to absorb sunlight. Gently dust plants with a mildly damp cloth.
Use your best judgment when harvesting in the ash zone of a wildfire. Any amount of construction ash can still be harmful. Covering your garden will help, but you’ll still want to take precautions when harvesting.
Luckily fruiting crops like tomatoes don’t absorb through the skins of the fruit. Still, wash fruits three times to ensure you’ve removed all the ash debris. Use a soft brush on the more porous fruiting crops (like beans) while washing. As an extra precaution, peel fruiting crops that can be peeled and dispose of the peel.
For root crops, so long as a large amount of ash doesn’t fall on the garden and get absorbed into the soil, you can safely harvest roots and give them an extra rinse or two. However, cut and dispose of any root tops exposed above ground.
For herbs and leafy crops, you’ll want to take the most precaution. Leaves are more absorbent and porous so there is more potential for contamination. Leaves that are soft and fuzzy (like sage and comfrey) should not be eaten. If you’re farther away from the fire and the ash is light and you’ve been dusting the leaves, you’ll still want to wash your shiny leafy greens multiple times.
The closer you are to the fire, the less you should harvest. Pay close attention to the health of your plant and consider how much ash your plant is being exposed to. If there’s a thick heavy layer of ash or you’re downwind from a construction zone burn, don’t harvest. It’s better to be safe.
The good news is, that doesn’t mean you have to start all over and lose your plants! Instead, take note of where the ash is, dust leaves and remove as much ash from the soil as you can. Once the fire is out and the air has cleared, remove as many leaves as you can. For crops like kale and chard, remove all but the 3-5 inner most leaves. For lettuce, cut the whole head off about 3” above the soil line (most lettuces will grow back again if not cut too short). For herbs, prune them as deeply as you can. Once the new growth has appeared, you can begin harvesting again.