Editor's note: Master Gardeners are keeping busy in their own gardens during Napa County's “Shelter in Place” directive. It's spring, it's getting warmer, it's a great time to work in the garden! Here's how Master Gardeners are spending their time:
by Melody Kendall
One of the positive things in my life since the ‘shelter in place' order is my garden. It is my refuge and escape. Who knew that the family that I love more than words can express could drive me so bananas! So, I am out in my garden much of the time just puttering around.
Recently, I have been taking my frustration out on the weeds. February had many warm days and no rain, but the weeds are, of course, flourishing. Doesn't it always feel that way? You can purchase a plant and baby it along knowing full well there are no guarantees it will survive. But a weed will persevere under what seems to be the worst conditions, and despite fervent wishes and efforts aimed at its demise, will look healthier every day. 
To discourage those pesky weeds I have two methods I have found to be the most successful. First is decapitation to the ground level using of a stirrup-style hoe. I use it in garden beds and loose mulch and gravel areas. I used to laboriously pull the weeds out and then till the soil, but I have since learned that leaving the roots of the weeds in the soil and using minimal tillage can actually benefit the soil health.
The second method I use on compacted areas like my decomposed granite paths and seating areas is a spray herbicide. This way I don't disturb the compacted surface when I kill the weed. With the recent research into the use of glyphosate and possible unwanted secondary effects of its use, I decided to look for an effective safe alternative for weed control. I found some interesting data on the use of white vinegar that has acetic acid as the active ingredient.
It isn't a ‘magic bullet' but there have been some positive results with the use of white vinegar. The white vinegar in my kitchen is only a 5%-8% concentration and considered safe as a weed killer with a minimum risk factor. Any product with a concentration of acetic acid of 8% or more must be EPA-registered as an ‘active ingredient' as a pesticide product, and I can understand why a higher concentration is dangerous. So, I decided to give the household white vinegar a try. No matter what concentration vinegar you use, it can be harmful to your eyes and skin, so protect yourself by wearing eye goggles and gloves.
I purchased a gallon of white vinegar in the salad dressing aisle at the grocery store. After gloving and goggling up, I filled my pump sprayer with the undiluted 5% vinegar solution and headed out to the garden on a mission. It is very satisfying to spray all the little weed seedlings and to return the next day to brown, desiccated and very unhappy weeds. Sometimes it took more than one application, but responsible use of something better for me and the environment has great satisfaction that helps justify the extra work.
It is important to note that you need to clean all your equipment thoroughly immediately after use. I thought I'd keep a spray bottle full of vinegar ready to spritz random weeds at will - not a good idea. Within a week the spay mechanism was corroded because the acetic acid had eaten through the gaskets. Protect your equipment and always clean it thoroughly after use.
There are multiple ‘wins' to my adventure. I know the weeds will never be entirely eradicated in my yard (there are always weeds seeds waiting for that perfect spot to light), but I now have another method in my arsenal to relieve some stress with an added benefit of feeling good about the methods I have chosen.
Happy weeding.
References:
Northwest Center for Alternatives to Pesticides http://www.pesticide.org/vinegar_herbicides
Soil info: UC Integrated Pest Management http://ccmg.ucanr.edu/files/141617.pdf
UC Davis-Vegetable Research and Information Center https://anrcatalog.ucanr.edu/pdf/7248.pdf
During Napa County's shelter in place directive that protects everyone's health and safety, Napa Master Gardeners are available to answer garden questions by email: mastergardeners@countyofnapa.org. or phone at 707-253-4143. Volunteers will get back to you after they research answers to your questions.
Visit our website: napamg.ucanr.edu to find answers to all of your horticultural questions.
Photo credits: "Summa"- Pixabay free picture