Sacramento Digs Gardening logo
Sacramento Digs Gardening Article
Your resource for Sacramento-area gardening news, tips and events

Articles Recipe Index Keyword Index Calendar Twitter Facebook Instagram About Us Contact Us

'Ash Wednesday' follows nearby wildfires

Smoky haze can affect tomatoes, grapes

Elephant ear leaf with ash
Ash particles pepper an elephant ear leaf. Rinse off the debris. (Photos: Debbie Arrington)

Ash on concrete
Use a broom or hose to remove ash from the patio, not a leaf blower.

It’s raining ash! After all this high heat, what’s that going to do to the tomatoes?

Wildfires in Solano and Napa counties have filled our skies with smoke and ash, which can travel many miles from burn areas. It’s unhealthy for people or pets to be outdoors.

When we do go outside, everything is dusted with fine particles of ash. And it’s still stifling hot.

If working around ash, wear protective clothing such as long sleeves, long pants, gloves, googles and (of course) a face mask. If ash gets on your skin, wash off promptly.

Don't use a leafblower for ash removal. It just puts it back into the air.

Instead, consider where that ash came from and how your garden can cope.

Most plants will be just fine. They deal with smoke better than we do. As they process carbon dioxide, they also help filter out smoke, cleaning the air. Another benefit: That smoky haze can act like cloud cover and lower temperatures. We might finally break our streak of triple-digit days.

But smoke also contains particulate matter that clogs leaf pores and hampers this cleansing process. This gritty residue can coat the outside of vegetables and fruit, too.

To remove ash residue, spray plants gently with water -- preferably early in the morning. That acts like a rain shower, nature's way of rinsing away debris.

The crops most vulnerable to smoke: Grapes and tomatoes. Both can absorb smoke into their skins, causing what's called "smoke taint" to their flavor. (Winemakers refer to it as "ashtray taste.") The volatile phenols in ash and smoke also are absorbed by the plant's leaves.

Most grape growers wash the smoke residue off picked fruit instead of rinsing their vines. They also may discard the grape skins before processing. Consider that same approach if processing your own homegrown grapes or tomatoes.

As for the ash, it can cause a gritty film on tomatoes and other vegetables. It tends to stick to tomato skin or kale leaves, more so than ordinary dirt.

Ash particles on a red rose
Ash accumulates on petals of a Trumpeter rose.
Not all ash is the same. Ash from burning forests or grasslands is similar to fireplace ash; it's acidic, even beneficial to a garden, and generally safe. That ash and any smoky residue could be scrubbed off with water and a little dish soap. then rinsed and dried. For leafy greens, submerge completely in a basin filled with water and a teaspoon of soap, then scrub, rinse and pat dry.

Ash from chemical fires, destroyed buildings or burned-out automobiles can be harmful. (That’s the type of ash we get if neighborhoods burn in wildfires.)

Vegetables covered with that ash residue should be discarded, UC master gardeners recommend.


0 comments have been posted.

Newsletter Subscription

Sacramento Digs Gardening to your inbox.

Taste Summer! E-cookbook


Find our summer recipes here!

Local News

Ad for California Local

Taste Spring! E-cookbook


Find our spring recipes here!

Thanks to our sponsor!

Summer Strong ad for

Garden Checklist for week of July 7

Take care of garden chores early in the morning, concentrating on watering. We’re still in survival mode until this heat wave breaks.

* Keep your vegetable garden watered, mulched and weeded. Water before 8 a.m. to conserve moisture.

* Prevent sunburn; provide temporary shade for tomatoes, peppers, eggplant, melons, squash and other crops with “sensitive” skin.

* Hold off on feeding plants until temperatures cool back down to “normal” range. That means daytime highs in the low to mid 90s.

* Don’t let tomatoes wilt or dry out completely. Give tomatoes a deep watering two to three times a week. Harvest vegetables promptly to encourage plants to produce more.

* Squash especially tends to grow rapidly in hot weather. Keep an eye on zucchini.

* Some weeds thrive in hot weather. Whack them before they go to seed.

* Pinch back chrysanthemums for bushy plants and more flowers in September.

* Harvest tomatoes, squash, peppers and eggplant. Prompt picking will help keep plants producing.

* Remove spent flowers from roses, daylilies and other bloomers as they finish flowering.

* Pinch off blooms from basil so the plant will grow more leaves.

* Cut back lavender after flowering to promote a second bloom.

* One good thing about hot days: Most lawns stop growing when temperatures top 95 degrees. Keep mower blades set on high.

* Once the weather cools down a little, it’s not too late to add a splash of color. Plant petunias, snapdragons, zinnias and marigolds.

* After the heat wave, plant corn, pumpkins, radishes, winter squash and sunflowers. Make sure the seeds stay hydrated.

Taste Fall! E-cookbook

Muffins and pumpkin

Find our fall recipes here!

Taste Winter! E-cookbook

Lemon coconut pancakes

Find our winter recipes here!