- Author: Bob Niklewicz PT, UC Master Gardener of Napa County
Okay, be honest. When you have a plant that is not doing well and you look for help from your favorite book, website, or YouTube source, and they start talking about pH, do your eyes roll back?
First, let's define the term. In 1909 Danish biochemists decided to use pH as shorthand for potential hydrogen. They developed a pH scale, ranging from 0 to 14, to represent how many hydrogen ions (H+) are present in a sample. According to the scale, distilled water is a 7 (neutral). Anything under seven is considered acidic (sour), while anything above 7 is alkaline (sweet).
These values are not linear but, rather, logarithmic. That means that a sample with a pH of 6 is 10 times more acidic than a sample with a pH of 7.
What does pH have to do with gardening? Everything. A soil's pH affects the ability of plant roots to absorb nutrients and water. Most minerals in the soil must be dissolved to be absorbed by a plant's roots. Soil that is slightly acidic (6.2 to 6.8) or slightly alkaline (7.4 to 7.8) will dissolve minerals the best.
When soil is too acidic (pH below 5.5) new foliage looks yellow, distorted and possibly black around the edges and the plant does not grow. When soil is alkaline (pH above 8), plant leaves may look yellow between the veins or have a bleached or mottled and blotchy look. New growth may have brown or black leaf tips.
If you read that last paragraph again, you'll notice that the symptoms of pH imbalance are roughly the same, whether pH is too high or too low. That's indeed true but once you know the target soil pH for your plant, you can find information on how to adjust it.
The key point is that hydrogen drives the process of photosynthesis in the leaves and plant respiration in the roots. Both functions promote plant growth and health. Too much hydrogen or too little can reduce a plant's viability. Just like Goldilocks, you are looking for “just right.”
So don't think of pH as a scary word. Rather, think of it as the Teeter Totter of garden soil. Let's say you test your soil and find that it has a pH of 7.5 but you want it at 6.8. Adding acidic soil amendments, such as pine needles or coffee grounds, or an acid fertilizer, can shift the fulcrum. And a change in pH can be powerful. Just lowering the soil pH to a range of 5.2 to 5.5 can turn a pink hydrangea blue.
But be aware that it can take months for soil amendments to make a difference. If you rotate crops, the pH of the soil you amended last year may not be the best for this year's veggies. Save yourself some grief and experiment on smaller areas, such as planter boxes, rather than trying to adjust pH on a large plot. Test the soil a couple of times a year and make smaller adjustments frequently.
Of course, the best way to get accurate information about your soil's pH is to send samples to a laboratory for testing. For a fee, they will analyze your soil samples, but this can get pricy.
If you are a DYI person, start out with a small defined plot. Wearing gloves, take samples from four to five areas at a depth of four to six inches. Combine the samples in a clean, dry bucket. Remove debris such as sticks, rocks or dead plant parts. Add distilled water until the soil is a thick paste. Then dip your testing device into the bucket and follow the key on the packages to determine the pH of your sample.
Finally, with results in hand, you can amend the soil to achieve the desired pH. Not sure what amendments to use? Ask the staff at your local nursery. Read the labels on amendments for instructions. Study up on the nutritional requirements of your plant to know if you even need to correct the pH. Or contact the Napa County Master Gardener help desk (hours below). When you learn how to test and amend your own soil, you won't think of pH as a frightening term anymore. In fact, when your plants start to look great, you will be pH (pleasantly happy).
Fall Faire: Join the UC Master Gardeners of Napa County for an entertaining and educational event on Saturday, September 28, from 1 pm to 4 pm, outdoors at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Enjoy exhibits on composting, monarch butterflies, succulents, water conservation, bees and more. The program includes activities for kids, a scarecrow contest, giveaways, and music. Admission is free.
Library Talk: Join UC Master Gardeners of Napa County and Napa Public Library for a free talk on “Thirsty Lawn to Low-Water Succulents and Perennials: A Step-by-Step Guide” on Thursday, October 3, from 7 pm to 8 pm, via Zoom. Don't let analysis paralysis stop you from achieving your new climate-appropriate garden. Join the UC Master Gardeners of Napa County on a step-by-step journey from weedy, labor-intensive lawn to a garden of succulents and perennials with year-round color. Register here.
Become a Master Gardener Volunteer: UC Master Gardeners of Napa County is now accepting applications for the Class of 2025. Visit napamg.ucanr.edu to read the informational brochure, then register to attend a mandatory information session for applicants. Application deadline is 5 pm on September 25.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.
- Author: Kathy Keatley Garvey
It's the birthday anniversary of noted entomologist Richard "Doc" Bohart (1913-2007), founder of the Bohart Museum of Entomology, University of California, Davis.
So when the Bohart Museum hosts a public open house (theme:"Museum ABCs: Arthropods, Bohart and Collecting") from 1 to 4 p.m., Saturday, Sept. 28, plans also call for a tribute to him and his work.
"Doc" Bohart founded the insect museum in 1946 and served as its first director; compiled 32 years on the entomology faculty; and became an internationally recognized entomologist and author.
Born Sept. 28, 2013 in Palo Alto, Richard began collecting butterflies at age 7. "He and his brother George 'Ned' Bohart collected butterflies for a local collector to earn pocket money," according to UC Davis distinguished professor emerita Lynn Kimsey, who directed the Bohart Museum for 34 years until her retirement on Feb. 1, 2024.
Bohart attended UC Berkeley, receiving three degrees in entomology culminating in his doctorate in 1938. He joined the UC Davis faculty in 1946 and chaired the Department of Entomology from 1956 to 1965. He taught general entomology, medical entomology, systematics, and agricultural entomology.
According to the Academic Senate's memorial, Bohart "contributed substantially to the world literature of the insect Order Hymenoptera, which included two landmark books, Sphecid Wasps of the World (with A. S. Menke), and The Chrysidid Wasps of the World (with L.S. Kimsey), as well as 230 journal articles and four other books on wasps and mosquitoes, including the second and third editions of The Mosquitoes of California (the second with Stanley B. Freeborn and the third with Robert K. Washino). During his career, he described more than 200 new species and genera of insects."
Today the Bohart Museum is the home of a global collection of eight million insects; a live petting zoo (including Madagascar hissing cockroaches, stick insects and tarantulas); and an insect-themed gift shop, stocked with T-shirts, hoodies, jewelry, books, posters, and collecting equipment. The new director, only the third since 1946, is Professor Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology, and associate dean of the UC Davis College of Agricultural and Environmental Sciences.
"His teaching and collecting activities resulted in the development of one of the finest collections of stinging wasps in the world in the Bohart Museum of Entomology," Kimsey said. "A great deal of this material was obtained through his collecting and that of his students. During his tenure, the museum collection grew from 500 specimens to 7 million, a span of some 60 years. Chancellor James Meyer dedicated the entomology museum in his name in 1983. The R. M. Bohart Museum moved into a new building in 1994 and was dedicated by Chancellor Larry Vanderhoef."
Open House. The open house, free and family friendly, will include "an overview of terrestrial arthropods which encompasses everything from insects, arachnids, millipedes, isopods and centipedes," said Tabatha Yang, education and outreach coordination. "We will also showcase some of the trapping/catching methods we use, for example, nets, lights, pitfall traps and malaise traps."
Pinning, spreading and curation demonstrations are planned "so people know how to take care of and preserve a dead arthropod for research or for a personal collection," Yang said. "People sometimes find a dead dragonfly or a butterfly on the ground and we often get asked how they can preserve it."
"We also get asked a lot of questions about our own collection and why the specimens don't decay," she added. "We will highlight the different curation techniques from pinning, point mounting, preserving in alcohol and mounting on slides."
Entomologist Jeff Smith, curator of the Lepidoptera collection, which encompasses some 750,000 specimens, will demonstrate and discuss the various steps of relaxing, pinning, spreading, and labeling moths and butterflies.
A Bohart volunteer since 1998, Smith has spread the wings of some 180,000 moths and butterflies, typically 6,000 or more each year for the past 30-plus years. He has crafted and donated some 2,475 wooden specimen drawers, including 110 so far this year. He also has donated some 100,000 specimens (primarily butterflies, moths but a few other insects, including beetles) to the Bohart Museum.
- Author: Maggie Swanson
My name is Maggie (she/her), HREC's newest GrizzlyCorps fellow, alongside Brenda. Under the mentorship of Hannah Bird and John Bailey, I will be supporting the REC in land management projects and youth education programs.
I hail from Milton, Massachusetts, a town just south of Boston. I lived in New England through my early twenties, graduating from Middlebury College in Vermont in February, 2023 with a degree in Conservation Biology and minor in Computer Science. I spent the summers tending a local organic farm; monitoring endangered shore birds; and diving for coral reef research in the Caribbean in an effort to immersively understand our planet's varied ecosystems. After graduation, I forged my way West and hiked the Pacific Crest Trail to witness our changing climate in a region defined by a scarred biosphere. I encountered unprecedented snowfall, heatwaves, and wildfire across the 2,650-mile trail which cemented an interest in working toward rural climate resiliency in California. Last spring, I returned to Marin County and studied Spotted Owls with Point Blue Conservation Science and am filled with gratitude to be back working in and among Hopland's beautiful oak woodlands here at HREC.
I am most excited to work alongside life-long learners: preschoolers bottle-feeding lambs for the first time; post-docs investigating biological and ecological data years in the making; and tribal leaders who have stewarded this land since time immemorial. Cheers to embarking on a new service year!
- Author: Jennifer M Baumbach
Join us for a hands-on, creative adventure where you'll design a one-of-a-kind succulent centerpiece to bring your holiday table to life. Using beautifully vibrant, locally grown Master Gardener succulents paired with natural embellishments, you'll unleash your creativity and leave with a stunning masterpiece! Plus, enjoy light refreshments as you mingle with fellow plant lovers in a relaxed, festive atmosphere. Don't miss this chance to make something truly special while having a blast—reserve your spot now!
https://surveys.ucanr.edu/survey.cfm?surveynumber=43412
Dehydrated Zucchini Flour
Lynn Pastusak, UC Master Food Preserver Volunteer
I went out of town for four days and came home to massive zucchini!! What was I going to do with these monsters? I hate to throw away good food, especially beautiful home grown food. Then I had an ah ha moment, I could make zucchini flour!
Zucchini flour? What's that? It's mild flavored and gluten-free. That sounds nourishing, I thought, and I can hide it in my recipes! I'd never done it, but it sounded like a fun project and a great way to keep a big zucchini in a small container.
The very first thing to do is make sure all your kitchen supplies and surfaces are scrubbed clean and sanitized. Is there a difference? Absolutely. Find more information here about cleaning, sanitizing and disinfecting. After everything is squeaky clean, scrub the zucchini with a vegetable brush under running cold water. Don't put the zucchini in a sink or bowl full of water. The germs and bacteria will just float around. The running water washes all the bad stuff down the drain.
Then cut the zucchini into manageable sizes and remove the seeds. I used a grapefruit spoon. Its little, sharp, serrated teeth worked perfectly and made the job of scraping out all those seeds and pulp easy.
Next, you will need to decide whether to pare or not to pare the zucchini. If you leave the peel on, the flour will be a bit greener in color. Also, the peel may be bitter. Taste the peel before you pare it and decide what is best for you. The peel was not bitter on my zucchini, but I wanted to see the color and texture difference of my flour. I'll show the results later.
Then, cut the zucchini into workable pieces and grate them using a handheld cheese grater - or if you have a rotary grater or electric grater, it will go a lot faster. I used my electric grater, and it was super fast!
Zucchini holds a lot of moisture. The wetter it is, the longer it will take to dry in the dehydrator so you will want to dry the grated zucchini as much as possible. You can do this by placing the grated zucchini in a colander for about 15 minutes and pressing down on it to squeeze out the liquid or by squeezing the grated zucchini with a potato ricer. Another way, and is how I did it, is to lay some paper towels on a cloth towel; place a layer of grated zucchini on the paper towels; place another layer of paper towels on top of the zucchini; roll the towel up tightly and squish with your hands to absorb the liquid.
After the zucchini has released enough liquid, preheat the dehydrator to 135°.
Place the drained grated zucchini on the dehydrator trays. The pieces are pretty thin, so you don't have to worry about spreading the grated zucchini out sparsely. It's ok if some are overlapping a bit. You might want to stir them gently after a couple hours of drying in case there are some patches not drying as quickly because they are overlapped and stuck together.
Heat the grated zucchini in the dehydrator. The University of Maine Cooperative Extension recommends heating zoodles, which is a type of grated zucchini, at 135° until the zucchini is very dry and crispy. It's difficult to determine the exact heating time as moisture in the air (humidity) has a major impact on drying time, but it should take about 7-11 hours.
Remove the dried grated zucchini from the dehydrator.
Now comes the fun part! Fill your blender, food processor, or chopper about 2/3 full with the dehydrated grated zucchini and grind it until it is finely ground. Any grinder will work. Some grind finer than others. I used my Vitamix and it ground it to a very fine consistency.* (Read the important note below before removing the lid.)
Congratulations! You've just made flour!
*Important! After you are done grinding, keep the lid on your grinder for a few minutes to let the dust settle. If you don't, you will have a cloud of zucchini dust puff out all over the place when you remove the lid. It can be quite messy and it's not good to inhale all those fine particles.
Remember, I mentioned that I wanted to experiment with leaving the peel on or off. I left the peel on the first batch and pared the second batch. It's difficult to tell with the photos, but there was a slight difference in color; the peeled zucchini was a pale green and the unpeeled zucchini was a bit darker green. I did not notice a difference in the texture or taste. Therefore, I just combined both flours into one container.
Store the zucchini flour in an airtight container, such as a mason jar with a tight-fitting lid. You can also vacuum seal the jar lids for longer lasting storage. The zucchini flour tends to pull moisture from the air which can cause clumping and molding. To prevent this, you may add a food safe silica packet to absorb the moisture. This is optional, but well worth it. You can read more about silica packets here.
Do not store the zucchini flour in the refrigerator. There is too much moisture in the refrigerator which will undo all your dehydrating work.
Use your beautiful zucchini flour within 6 months for best taste; however, it can be stored for up to 1 year, especially with a silica packet. Not sure if it is good? Smell it; it's no good if it smells musty. It's no good if it is wet and has large clumps of mold. Here's an article to tell you more about bad flour.
So, how much flour will you get? Roughly 3 ½ pounds of zucchini will make about 2 cups of dried shredded zucchini which will end up making a scant ½ cup of zucchini flour.
Now that you have successfully made the zucchini flour, what do you do with it? You can make cakes, breads, cookies, muffins, and quick breads that don't require a lot of rising time since there is no gluten in the zucchini flour. Zucchini flour can replace coconut flour (1:1 ratio). You can replace 1/4 to 1/3 cup of regular flour with the zucchini flour (1:3-4 ratio). (I've been told you might want to add 1-2 tablespoons additional water or oil and mix it extra well.) Try adding some of the zucchini flour to soups, stir fries, casseroles, smoothies, scrambled eggs, or pancake batters. Have fun and add color and nutrition by adding a bit (not a lot) when making pasta (1:10 ratio).
There are a variety of easy to make recipes using alternative flours, such as zucchini flour, available on food blogs. A quick Google search will turn up many options. Find a reliable source for recipes and have some fun experimenting in the kitchen!
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