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

Wildfire brings more ozone problems

Sacramento Digs Gardening
BY Debbie Arrington PUBLISHED AUG 30, 2021

These citrus leaves show ozone damage. (Photo

courtesy UC IPM)

Hot, smoky conditions
create high pollutant levels

Plants may be able to cope with wildfire smoke better than people. But ozone is another matter.

After prolonged exposure to two weeks of wildfire smoke, foliage on many plants in the greater Sacramento area are showing signs of ozone damage. It starts out as stippling – little dots all over large leaves. Or parts of leaves may look like they were sun-bleached white or silver.

In my Sacramento garden, I noticed it in particular on a large dahlia plant. Besides funky foliage, its vivid red petals also were bleached white at the tips. That bleaching was accompanied by a build-up of soot on its leaves.

Ozone is what happens when wildfire ash and other pollutants get “cooked” by triple-digit heat. It makes our eyes water and throats hurt. And there’s a lot of it right now.

According to Sacramento region air quality monitors, our air quality is rated “very unhealthy” for the next several days with particle levels remaining high, especially in El Dorado and Placer counties. Through at least Thursday, Sacramento is forecast to rate 250 on the Air Quality Index. (“Good” is below 50.)

While ozone high up in the atmosphere is a good thing, ground-level ozone can be dangerous. In our case, it’s created by a combination of wildfire ash and other pollutants (usually nitrogen oxides and volatile organic compounds), intensified by bright sunlight and triple-digit heat.

Ground-level ozone can prevent a plant's leaves from properly doing their job. Ozone enters the leaf's stomata and burns the leaf's tissue.

Signs of ozone damage include dark stippling and bleaching of foliage. Plants lose their vigor and stop blooming or yielding fruit. Ozone damage weakens the plant and makes it much more susceptible to pests and disease.

Worried about the long-term effects of too much ozone, researchers and the National Park Service surveyed plants in national parks across the country and found hundreds of species with ozone sensitivity from ash and asters to sycamores and yarrow. Maple, cherry, polar and plum trees are all on the ozone-sensitive list. Find it here: https://irma.nps.gov/NPSpecies/Reports/Systemwide/Ozone-sensitive%20Species%20by%20Park

Meanwhile, keep plants hydrated. Wash ash and soot from leaves. Lower temperatures later this week may bring some ozone relief, too.

Comments

0 comments have been posted.

GENERAL GARDENING

An article about gardening.

Keywords:

ash Sacramento plant vigor smoke wildfires weather gardening gardening in smoke air pollution heat air quality ozone UC IPM

Newsletter Subscription

Sacramento Digs Gardening to your inbox.

Taste Summer! E-cookbook

Find our summer recipes here!

Thanks to Our Sponsor!

Local News

Taste Spring! E-cookbook

Find our spring recipes here!

Sites We Like

Garden Checklist for week of July 21

Your garden needs you!

* Keep your vegetable garden watered, mulched and weeded. Water before 8 a.m. to reduce the chance of fungal infection and to conserve moisture.

* Feed vegetable plants bone meal, rock phosphate or other fertilizers high in phosphate to stimulate more blooms and fruiting. (But wait until daily high temperatures drop out of the 100s.)

* 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.

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

* 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.

* It's not too late to add a splash of color. Plant petunias, snapdragons, zinnias and marigolds.

* From seed, plant corn, pumpkins, radishes, winter squash and sunflowers.

Taste Fall! E-cookbook

Find our fall recipes here!

Taste Winter! E-cookbook

Find our winter recipes here!